Research on Shape Memory Performance of TPI/PE Composite Materials

doi:10.21203/rs.3.rs-4849022/v1

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Research on Shape Memory Performance of TPI/PE Composite Materials

https://doi.org/10.21203/rs.3.rs-4849022/v1

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Triple shape memory materials have become a major research hotspot in recent years. Trans-1,4-polyisoprene (TPI) was mixed with inexpensive polyethylene (PE) in this work, and TPI/PE shape memory polymer composites (SMPCs) were vulcanized using the dynamic vulcanization process. PE can be divided into low-density polyethylene (LDPE) and high-density polyethylene (HDPE), both have the same structure but different molecular chain arrangement and density. Since the properties of SMPC are different due to the different ratios of TPI and PE components, choosing the right ratio is especially important for triple shape memory materials. We investigated the triple shape memory properties of composites of TPI with LDPE and TPI with HDPE at different ratios (8:2,7:3 and 6:4), respectively. The impact of the dynamic vulcanization system on the mechanical and shape memory characteristics of the TPI/PE hybrid SMPC was discovered through a sequence of studies. The results showed that when the ratio of TPI/PE was 8:2, the composites had the fastest vulcanization rate and the largest cross-linking degree with the highest tensile strength and mechanical properties. In addition, the test results show that the crystalline properties of HDPE-based composites are consistently higher than those of LDPE-based composites. The shape memory properties of TPI/HDPE composites are more excellent than those of TPI/LDPE composites at the same ratio. The best triple shape memory properties were obtained at a TPI/HDPE composite ratio of 8:2. We believe that the relevant findings of this study can provide a valuable design reference for the development of high-performance TPI shape memory materials.

Dynamic vulcanization system

TPI

LDPE

HDPE

Shape memory properties

Shape memory material (SMM) is a new type of smart-responsive material[1], after changing its initial state and fixing it under certain conditions, can be restored to its initial shape by stimulation with external conditions such as heat, electricity, light, and chemical induction[2–4].Shape memory polymers are widely used in sensors, actuators, aerospace, 4D printing and biomedical applications due to their unique advantages such as tunability, multiple stimuli, multiple shape memory effects and versatility[5–16]. Common shape memory polymers usually include reversible and stationary phases [17]. The stationary phase is usually the chemical and physical cross-linking point within the polymer, while the reversible phase is used to fix the temporary shape of the material and undergoes freezing or softening near the material's transition temperature. In current studies[18–20], research on shape memory polymers has focused on developing polymers with multiple shape memories. Currently, there are two techniques to achieve this effect, physical blending and chemical synthesis. Through polymer blending, polymer composites have different reversible phases or unique cross-linking network designs; polymer blending is cheaper to produce, easier to operate, and more suitable for industrial production than chemical synthesis methods.

TPI, also known as synthetic duralumin rubber, is a thermosensitive shape memory polymer (SMP) obtained by molecular reorganization and modification using modern polymer synthesis and modification techniques [21–23]. TPI is a significant subset of cross-linked polyolefin materials that are frequently utilized in the creation of SMPs that respond to temperature[24, 25]. Under certain conditions, TPI and its polymers are given a certain initial state of shape. When the external temperature exceeds the phase transition temperature (Tt) of the shape memory polymer, an external force is applied to change its shape accordingly, and then it is cooled below Tt to fix its shape and eliminate the external force. If the external temperature exceeds Tt again in a specific way and law, it can be reversibly restored to the initial state, completing the cycle of memorizing the initial state - deforming the state - restoring the initial state[26–28]. TPI is often blended with other materials when used as a triple shape memory matrix. For example, Tian et al [29] reported a novel triple shape memory elastomer, which uses paraffin, TPI as the reversible phase, and a lightly crosslinked TPI network as the stationary phase to provide the driving force for recovery. GUO [30, 31] used short carbon fibers as fillers to improve the mechanical properties and shape restoring force of TPI matrix. However, the composite of TPI and other materials is less studied in the field of triple shape memory.

Polyethylene is widely used in industry, agriculture and daily life due to its relatively low price and good mechanical and processing properties [32]. Low-density polyethylene (LDPE) and high-density polyethylene (HDPE) are typical crystalline polymers with crystallinity of 55–65% and 80–90%, respectively. In this study, composites with triple shape memory function were prepared by mechanical melt blending of TPI with LDPE and HDPE, respectively. In this work, TPI SMPC was vulcanized using the dynamic vulcanization technology, which took processing safety and vulcanization efficiency into account. The technique of creating hybrid thermoplastic elastomer materials by melting plastic and rubber together in the presence of vulcanization aids following high-speed shear treatment is known as dynamic vulcanization[33]. A common process for creating thermoplastic elastomers is dynamic vulcanization [34].

The effects of the ratio of TPI-LDPE and the ratio of TPI-HDPE on the vulcanization characteristics, mechanical strength, crystalline properties and triple shape memory properties of the composites were investigated respectively. The mechanical properties and shape memory properties of the composites were improved while realizing the triple shape memory. Finally, by comparing the various properties of two different composites in equal proportions, a triple shape memory polymer with good mechanical properties was found. It is hoped that this study can provide a reference for the development and utilization of new TPI composites.

2.1. Materials and preparation

TPI: was purchased from Qingdao Dipai New Material, trans content ≥ 97%; LDPE and HDPE: Q/SY DH0016-2006, China National Petroleum Corporation Daqing Petrochemical Branch; Zinc Oxide (ZnO), Stearic Acid (SA), Accelerator NOBS(NOBS) and Sulphur(S) are all commercially available in industrial grades. The composite formulation table is shown in Table 1.

Set the temperature of XSS-300 Torque Rheometer (Shanghai Kechuang Rubber & Plastic Machinery Equipment Co., Ltd.) to 130°C and put TPI and LDPE/HDPE into it to realize uniform mixing. The order of adding materials should be: first add additives, then add fillers, and finally add sulfur. The mixture was mixed for 10 minutes and then the sample was taken out and the roller pitch was adjusted on the opener model BP-8175 (Dongguan Baopin Precision Instrument Co., Ltd.). Next, the mixed rubber was left at room temperature for 2 hours. After that, a rotorless vulcanizing machine model M-3000A (High Speed Railway Testing Instrument Co., Ltd.) was used to determine the positive vulcanization time (Tc90). After determining the Tc90, the TPI/LDPE/OC compound was vulcanized in a BP-8179 plate vulcanizing machine (Dongguan Baopin Precision Instrument Co., Ltd.). The vulcanized rubber samples should be left at room temperature for 16 hours, and then various performance tests can be conducted.

Table 1

Formulation of composite materials
Samples	A1	B1	C1	A2	B2	C2
TPI	80	70	60	80	70	60
LDPE	20	30	40	0	0	0
HDPE	0	0	0	20	30	40
ZnO	4	4	4	4	4	4
SA	2	2	2	2	2	2
NOBS	1.2	1.2	1.2	1.2	1.2	1.2
S	1.5	1.5	1.5	1.5	1.5	1.5

2.2 Performance testing

Vulcanization characteristics

According to GB/T16584-1996 standard, the test was carried out with a rotorless vulcanizing machine model M-3000A; the temperature of the test was set at 160℃, the duration was 60 minutes, and the applied pressure was 15MPa.

Mechanical properties

Prepare dumbbell shaped tensile test samples according to relevant specifications. According to the GB/T528-2009 standard, the AI-7000M tensile testing machine (produced by High Speed Railway Testing Instrument Co., Ltd.) is used to evaluate the mechanical properties of composite materials. Set the experimental environment temperature to 23 ° C and conduct a tensile test at a speed of 500mm/min.

Crystallization properties

Differential Scanning Calorimetry (DSC) analyses were performed on a Model Q20 instrument (TA, Inc., USA) and were completed under a nitrogen atmosphere with the flow rate of nitrogen maintained at approximately 0.1 MPa. The specific test procedure was as follows: first, the sample was rapidly warmed to 150°C and held for 2 min to ensure elimination of thermal history, followed by cooling to -20°C at a rate of 10°C per minute and again held for 2 min to stabilize the sample. Finally, the sample was reheated to 150°C at a ramp rate of 10°C/min and the crystallization and melting behavior of the sample during this process was recorded. Using these data and based on Eq. (1), the degree of crystallinity (Xc) of the TPI component of the composite can be calculated.

X_c=$\:\frac{\varDelta\:{H}_{m}}{\varDelta\:{{H}^{\text{*}}}_{m}}\times\:100\text{%}$, (1)

where $\:\varDelta\:{H}_{m}$ and $\:\varDelta\:{H}_{m}$* are the melting enthalpy of certain polymer portion and that of pure polymer (ca 277.1 Jg^− 1 for LDPE and ca186.8 Jg^− 1 for TPI), respectively[35, 36].

The composite material was cut into square samples with 15 mm side lengths and a TD-3700 model X-ray diffractometer (Dandong Tongda Instrument Co., Ltd.) was used for crystallinity analysis. The test was carried out at room temperature (23°C) with the angular scanning range set between 2θ = 1.5–10° and a scanning speed of 3°/mi.[37].

Shape memory performance test

The shape memory properties of the composites were evaluated using a Dynamic Mechanical Analyzer (DMA), Model Q800, manufactured by TA Instruments, Inc., USA, in the "controlled force" mode at a preload force of 0.0001 N and a frequency of 1 Hz. The dimensions of the rectangular samples used for the tests were 2.0 mm in thickness, 4.0 mm in width and 30.0 mm in length. The initial fixture spacing was adjusted to a range of 5.0 to 8.0 mm prior to the start of the experiment. The specific test procedure is described below.[38]:

Step 1: The specimen was held at a constant temperature of 150°C for 10 minutes, during which time a pressure of 0.1 MPa was applied to it.

Step 2: The temperature of the specimen was reduced to 70°C at a rate of 10°C per minute.

Step 3: Remove the pressure and hold the specimen at 70°C for 3 minutes while applying a pressure of 0.35 MPa.

Step 4: Continue to reduce the specimen temperature to -20°C at a rate of 10°C per minute.

Step 5: Remove the pressure and hold the specimen at -20°C for 5 minutes.

Step 6: Heat the specimen to 70°C at a rate of 10°C per minute and maintain a constant temperature for 5 minutes after reaching.

Step 7: Finally, heat the specimen to 150°C at a rate of 10°C per minute and hold at this temperature for 5 minutes.

Micromorphological characterization

The microstructural properties of the composites were examined by a scanning electron microscope (SEM), model JSM-7200F, manufactured by Nippon Electronics Corporation. In order to observe the details of the composites, sample strips that were fractured by stretching were selected and analyzed by SEM after they were subjected to gold spraying.

3.1 Vulcanization characteristics

Table 2 Table 3 and Fig. 1 reflect the vulcanization characteristics and vulcanization curves of different ratios of TPI/LDPE and TPI/HDPE hybridized SMPC during dynamic vulcanization, respectively. During dynamic vulcanization, process safety is reflected in the scorch time T_c10. The vulcanization process is safer the longer the scorch duration.. The results show that the charring time T_c10 shows a slow increasing trend with the change of the proportion of shape memory composites (SMPC). As a result, the processing safety of the dynamic vulcanization process increases significantly with decreasing TPI content and increasing PE content. The amount of time needed for the rubber to attain its maximum crosslinking density is known as the optimal curing time (T_c90). According to the data of vulcanization characteristics, it can be seen that T_c90 increases gradually with the change of SMPC ratio. This is because TPI is the main component involved in cross-linking in a dynamic vulcanization system, whereas PE hardly reacts with sulfur, making it difficult to produce mesh cross-linking. Therefore, SMPC is more difficult to reach the maximum degree of crosslinking, so it takes longer.

The minimum torque M_L of SMPC decreases as the ratio of TPI to PE changes. Since M_L indicates a material's fluidity, it follows that when the PE concentration increases during the first melting step of dynamic vulcanization, the fluidity of SMPC decreases. In the hot vulcanization stage, the vulcanization curve rises rapidly due to the cross-linking reaction between TPI and sulfur. As the ratio changes, the system's torque differential M_H-M_L(∆M) diminishes. Since M_H-M_L indicates the material's degree of cross-linking, it can be concluded that when PE content rises, SMPC's degree of cross-linking drops noticeably. This is due to the fact that as the ratio of SMPC changes, the TPI within SMPC that can chemically react with sulfur decreases, and less crosslinking network is formed, thus decreasing the degree of crosslinking. In addition, TPI/LDPE composites are consistently more cross-linked than TPI/HDPE composites. This is due to the fact that compared to LDPE, HDPE is denser, the molecular chain is more regular, and fewer molecular chains are able to physically cross-link with TPI, resulting in a lower degree of cross-linking.

Table 2

Vulcanization characteristics of TPI/LDPE composites
Group	T_c10/s	T_c90/s	M_L/dN·m	M_H/dN·m
A1	7.46	21.45	0.83	6.07
B1	8.08	22.31	0.68	5.03
C1	8.57	24.15	0.55	3.71

Table 3

Vulcanization characteristics of TPI/HDPE composites
Group	T_c10/s	T_c90/s	M_L/dN·m	M_H/dN·m
A2	2.92	8.38	0.77	5.08
B2	3.08	8.60	0.49	3.53
C2	3.24	9.49	0.36	2.07

3.2 Mechanical properties

The static tensile stress-strain curves of hybridized SMPCs made of TPI/LDPE and TPI/HDPE, with varying ratios, at 23°C are displayed in Fig. 2, and Fig. 3 depicts the difference in fracture stresses for different ratios of SMPCs. For the fracture strain in Fig. 2, it can be found that the strain decreases gradually with the increase of PE by the decrease of TPI in SPMC. This is because, when it comes to macro-stretching, TPI's molecular chains show more deformation than PE's since they are more prone to deformation. For the fracture stresses in Figs. 2 and 3, it can be noticed that the fracture stress decreases with the change of scale. The maximum values were increased by 167.7% and 184.9% compared to the minimum values of SPMC fracture stress for TPI/LDPE and TPI/HDPE, respectively. This is mainly due to the fact that with the change of SPMC ratio, the molecular chain inside the composite is more chaotic, and the intermolecular interaction force is greatly reduced by mechanical shear, so the tensile strength gradually decreases. In addition, it can be seen that the tensile strength of the TPI/HDPE composites with different ratios is higher than that of the TPI/LDPE composites. This is probably due to the fact that the density, hardness and crystallinity of HDPE are higher than that of LDPE, and during tensile deformation, the crystalline region will hinder the deformation of the composite material, and it requires a high force to break the crystalline part, so the tensile strength of the TPI/HDPE composite material is always higher than that of the TPI/LDPE composite material. Comprehensively comparing the stress-strain at fracture at different ratios of different SMPCs, the optimal physical and mechanical properties were found when the ratio of TPI/HDPE was 8:2.

Figure 2 Stress-strain curve of composite material

3.3 Crystallization properties

The crystallization characteristics of different ratios of SMPC are presented in Fig. 4, where Figs. A and B show the cooling crystallization and elevated temperature melting curves, respectively. Figures C and D show the melting temperatures of components TPI and PE, respectively. To get the crystallinity (X_c) of the two components, the enthalpies of melting of each component may be entered into Eq. (1), as shown in Figs. E and F. Combined with Fig. 4, it can be found that the variation of the ratio of the two components has a great influence on the crystallization properties of TPI. Figure C shows that the melting temperatures (T_m) of TPI are all shifted to lower temperatures as the proportion of SMPC is changed. This indicates that as the TPI content decreases, TPI is more likely to melt at lower temperatures, which means that the thermal stability of TPI decreases. In addition, it can be seen from Fig. D that the Tm of PE are shifted to high temperature with the change of SMPC ratio. However, the movement is more minute, which indicates that as the PE content increases, PE requires higher temperatures to melt, meaning that the thermal stability of PE is enhanced. As can be seen from Figures E and F, as TPI decreases PE increases, X_c (TPI) decreases significantly while X_c(PE) increases significantly. In addition the X_c(TPI) of TPI/HDPE is always higher than the X_c(TPI) of TPI/LDPE at a given ratio. This is due to the high degree of regularity of the HDPE molecular chain, during dynamic vulcanization the part of the TPI molecular chain involved in cross-linking is reduced, the crystalline part is increased, and the TPI molecular chain is arranged in a more regular manner. As shown by the vulcanization characteristics, TPI/LDPESMPC has a higher degree of cross-linking than TPI/HDPE, and the TPI molecules that have been cross-linked are broken up into tiny pieces and scattered throughout the composite matrix. This disrupts the ordering of the molecular chains within the TPI, ultimately leading to a gradual decrease in X_c(TPI). In addition, the X_c (HDPE) of TPI/HDPE is always higher than the X_c (LDPE) of TPI/LDPE. This is due to the fact that HDPE has a more regular and dense molecular chain than LDPE in the composite component, and therefore the composite containing HDPE has a higher degree of crystallinity in the same proportion.

Figure 5A shows the X-ray diffractograms of pure TPI, LDPE and HDPE and Fig. 5B shows the XRD spectra of the composites tested with different ratios. From the figure, it can be seen that the characteristic peaks of TPI, corresponding to diffraction angles (2θ) of 18.7° and 22.6°, respectively, and LDPE, corresponding to diffraction angles (2θ) of 21.3° and 23.7°, respectively; and HDPE, corresponding to diffraction angles (2θ) of 21.5° and 23.9°, respectively, can be seen. The three characteristic peaks between 30° and 40° are the XRD characteristic peaks of ZnO. The results show that the addition of additives does not affect the characteristic peaks of TPI, LDPE and HDPE, and TPI, LDPE and HDPE crystallize independently without eutectic. This implies that the two will not influence one another's crystallization in a given domain, which is a need for the triple shape memory characteristics.

3.4 Microstructural characterization

Figure 6 shows the microstructure of SMPC tensile sections at different scales. As the PE concentration rises, it is evident that the specimens have more holes in them. This is because the orderliness of the matrix molecules is destroyed by the random insertion of PE as a scattered phase into the TPI matrix. Furthermore, the molecular organization of PE is not significantly affected by the cross-linked TPI, and the dynamically vulcanized TPI is only partly vulcanized. When the ratio of TPI:PE is 8:2, the specimen has the fewest holes and the smoothest substrate surface, forming a flat, continuous organization. The results show that with the change of the ratio during the dynamic vulcanization process, the two components interlock with each other and the molecular chain arrangement is disorganized. The degree of TPI sulfidation's influence on crystallinity was found to be very compatible with the microstructure alterations of the sections in the DSC tests, hence enhancing the experiment's dependability.

3.5 Shape memory properties

Figure 6 shows the shape memory curves of DMA tests for different ratios of hybridized SMPC. As can be seen from the figure, the shape memory strain curve shows a stepwise recovery. There are two applied stresses and two withdrawn stresses in the figure. The stages experienced by the triple shape memory are, in order, fixation of PE, fixation of TPI, return of the second temporary shape and return of the first temporary shape. In this case, the stage of fixing the temporary shape before the second withdrawal of stress and the stage of returning to the initial shape after the second withdrawal of stress. All curves show a clear shape recovery process with a large shape recovery rate.

Figure 7 shows a schematic diagram of the principle of triple shape memory performance of TPI/PE composites. The disorderly dispersed lines in the figure indicate the macromolecular chain segments, and the red and blue colors indicate the molecular chains of TPI and PE, respectively. The red squares represent the crystallization zone of TPI and the blue squares represent the crystallization zone of PE. The yellow circle indicates the point of cross-linking of the molecular chain of the composite. When the temperature of the composite is above the melting temperature of the PE, all crystallized regions melt and the crystallized regions of TPI and PE form temporary shapes during stretching and cooling. After unloading the tension the composite is heated again and the crystalline zone melts and returns to its initial shape driven by the restoring force of the crosslinked network.

The crystalline region of TPI acts as a reversible phase, while the cross-linked portion and crystalline region of PE act as a stationary phase. The energy stored in the stationary phase and the reversible phase is gradually released when the temperature rises above the Tt of the two components. This causes the molecular kinetic energy of the reversible phase molecular chain to increase and the micro-Brownian motion to intensify, which forces the stationary phase to return to the entropy disorder state and realizes the shape recovery.

Tables 4 and 5 show the fixation and recovery rates of the triple shape memory properties of SMPC with different ratios. Where the fixation rate and the recovery rate were calculated by the following equation, respectively.

$$\:{R}_{f1}=\frac{{\epsilon\:}_{3}-{\epsilon\:}_{1}}{{\epsilon\:}_{2}-{\epsilon\:}_{1}}\times\:100\text{%}$$

$$\:{R}_{f2}=\frac{{\epsilon\:}_{5}-{\epsilon\:}_{3}}{{\epsilon\:}_{4}-{\epsilon\:}_{3}}\times\:100\text{%}$$

$$\:{R}_{r2}=\frac{{\epsilon\:}_{5}-{\epsilon\:}_{6}}{{\epsilon\:}_{5}-{\epsilon\:}_{3}}\times\:100\text{%}$$

$$\:{R}_{r1}=\frac{{\epsilon\:}_{3}-{\epsilon\:}_{7}}{{\epsilon\:}_{3}-{\epsilon\:}_{1}}\times\:100\text{%}$$

For the shape fixation rate (R_f) in the table, it can be seen that R_f1 gradually increases while R_f2 gradually decreases as the ratio changes. This is because the PE content gradually increases as the ratio changes, and in the first fixation stage, more crystals are involved in the first stage of fixation as the temporary shape is mainly fixed by the crystallized regions of PE. Thus, R_f1 gradually increases and TPI gradually decreases. In the second fixation stage, the temporary shape is fixed mainly by the crystalline regions of TPI, and the crystalline fraction of TPI involved in the second stage of fixation decreases, so R_f2 gradually decreases. In addition, as TPI content decreases and PE content increases, R_r1 gradually decreases while R_r2 gradually increases. This is because the first return to the temporary shape needs to reach the melting temperature of TPI, at this time the TPI crystalline region melts to become an amorphous form, the TPI crosslinked network is not limited by the crystalline region, and begins to shrink back to the initial state. As the TPI content decreases, the crosslinked network formed by the TPI matrix decreases, and the restoring force to return to the temporary shape decreases, so R_r1 gradually decreases. In addition, the second time to return to the temporary shape, it is necessary to reach the melting temperature of PE, at which time the PE crystallization region melts to become an amorphous form, and the crosslinked network, without the restriction of the PE crystallization region, begins to return to the initial state. As the PE content increases, there is more cross-linked network formed by the PE molecular chains to provide the restoring force, so R_r2 gradually increases.

R_a is the average of the fixation and recovery rates for each shape. From the table, it can be seen that there is the highest Ra when the ratio of TPI/LDPE composites is 7:3, which indicates that at this time TPI/LDPE composites have the best triple shape memory properties. TPI/HDPE composites have the highest R_a at a ratio of 8:2, when TPI/HDPE composites have the best triple shape memory properties. Therefore, the shape memory properties of TPI/HDPE composites are more excellent than TPI/LDPE composites at the same ratio.

Table 4

Shape memory properties of TPI/LDPE composites
TPI/LDPE	R_f1/%	R_f2/%	R_r1/%	R_r2/%	R_a/%
8:2	48.1	98.4	91.7	68.8	76.8
7:3	74.3	97.9	81.4	79.2	83.2
6:4	88.4	94.7	64.8	82.6	82.6

Table 5 Shape memory properties of TPI/HDPE composites

TPI/HDPE	R_f1/%	R_f2/%	R_r1/%	R_r2/%	R_a/%
8:2	81.9	96.9	99.6	72.6	87.8
7:3	96.0	89.8	83.0	76.3	86.3
6:4	96.9	84.2	50.0	82.7	78.5

In this paper, based on the TPI shape memory material, Both the preparation procedure and the dynamic vulcanization technique were enhanced. Through a series of studies, the differences between TPI/LDPE and TPI/HDPE composites, as well as the impact of the dynamic vulcanization system on the mechanical and shape memory characteristics of TPI/PE hybrid SMPC, were discovered. The results showed that SMPC with a TPI/HDPE ratio of 8:2 had the best thermomechanical and shape memory properties in the vulcanization system. Other innovative TPI SMPCs can be developed using this paper's study approach and results as a guide. The particular findings are as follows:

(1) The processing safety of the dynamic vulcanization process increases with increasing PE content. The process positive vulcanization time increases with increasing PE content during vulcanization. In addition, the degree of cross-linking of the composites starts to decrease as the PE content increases. When the TPI/PE ratio is 8:2, the composite has the fastest vulcanization rate and the highest degree of crosslinking.

(2) In static tensile tests, the fracture stress decreases with decreasing TPI content at different test temperatures. The composites have the highest tensile strength at a TPI/PE ratio of 8:2. In addition, the composites have the highest mechanical properties at a TPI/HDPE ratio of 8:2.

(3) Dynamic vulcanization system with the decrease of TPI content and the increase of PE has a greater effect on the TPI and PE components. The melt temperature of TPI moves to a lower temperature, while the melt temperature of PE moves to a higher temperature. X_c (TPI) decreases with decreasing TPI content and X_c (PE) increases with increasing PE content. In addition X_c(HDPE) is always higher than X_c(LDPE).

(4) In the shape memory test, Rf1 gradually increases while Rf2 gradually decreases with the change of SMPC ratio; Rr1 gradually decreases while Rr2 gradually increases. In addition, the TPI/LDPE composite ratio of 7:3 has the highest Ra, which indicates that at this time the TPI/LDPE composite has the best triple shape memory; TPI/HDPE composites have the highest Ra at a ratio of 8:2, when TPI/HDPE composites have the best triple shape memory properties. In addition, the shape memory properties of TPI/HDPE composites are more excellent than those of TPI/LDPE composites at the same ratio. The results showed that the composite with a TPI/HDPE ratio of 8:2 had the best shape memory properties.

Funding

This study was funded by the National Natural Science Foundation of China (Nos.51573124).

Data availability

All data generated or analyzed during this study are included in this published article. The data that support the findings of this study are available from the corresponding author upon reasonable request.

Declarations Conflict of interest

The authors declare that they have no conflict of interest.

Wang Z, Chang M, Kong F, Yun K (2019) Optimization of thermo-mechanical properties of shape memory polymer composites based on a network model. Chem Eng Sci 207:1017–1029
Zhao W, Liu L, Zhang F, Leng J, Liu Y (2019) Shape memory polymers and their composites in biomedical applications. Mater Sci Eng C-Materials Biol Appl 97:864–883
Yang H, D'Ambrosio N, Liu P, Pasini D, Ma L (2023) Shape memory mechanical metamaterials. Mater Today 66:36–49
Teng J, Wang Z, Liu J, Sun X (2020) Thermodynamic and shape memory properties of TPI/HDPE hybrid shape memory polymer. Polym Test, 81
Xiao X, Kong D, Qiu X, Zhang W, Zhang F, Liu L, Liu Y, Zhang S, Hu Y, Leng J (2015) Shape-Memory Polymers with Adjustable High Glass Transition Temperatures, Macromolecules, 48 3582–3589
Cui Y, Li D, Gong C, Chang C (2021) Bioinspired Shape Memory Hydrogel Artificial Muscles Driven by Solvents. ACS Nano 15:13712–13720
Wang Y, Wang Y, Wei Q, Zhang J (2022) Light-responsive shape memory polymer composites. Eur Polymer J, 173
Li Z, Zhang X, Wang S, Yang Y, Qin B, Wang K, Xie T, Wei Y, Ji Y (2016) Polydopamine coated shape memory polymer: enabling light triggered shape recovery, light controlled shape reprogramming and surface functionalization. Chem Sci 7:4741–4747
Gopinath S, Adarsh NN, Radhakrishnan Nair P, Mathew S (2023) Recent trends in thermo-responsive elastomeric shape memory polymer nanocomposites. Polym Compos 44:4433–4458
Karasu F, Weder C (2021) Blends of poly(ester urethane)s and polyesters as a general design approach for triple-shape memory polymers. J Appl Polym Sci, 138
Delaey J, Dubruel P, Van Vlierberghe S (2020) Shape-Memory Polymers for Biomedical Applications. Adv Funct Mater, 30
Xu C, Zheng Z, Lin M, Shen Q, Wang X, Lin B, Fu L (2020) Strengthened, Antibacterial, and Conductive Flexible Film for Humidity and Strain Sensors. ACS Appl Mater Interfaces 12:35482–35492
Wang Q, Li Y, Xiao J, Xia L (2023) Intelligent Eucommia ulmoides Rubber/Ionomer Blends with Thermally Activated Shape Memory and Self-Healing Properties. Polymers, p 15
Arun DI, Kumar KSS, Kumar BS, Chakravarthy P, Dona M, Santhosh B (2019) High glass-transition polyurethane-carbon black electro-active shape memory nanocomposite for aerospace systems. Mater Sci Technol 35:596–605
Alshebly YS, Nafea M, Ali MSM, Almurib HAF (2021) Review on recent advances in 4D printing of shape memory polymers. Eur Polymer J, 159
Ramaraju H, Akman RE, Safranski DL, Hollister SJ (2020) Designing Biodegradable Shape Memory Polymers for Tissue Repair. Adv Funct Mater, 30
Zheng X, Zhou B, Xue S (2019) A Viscoelastic-Plastic Constitutive Model of Shape Memory Polymer. J Mech 35:601–611
Huang YN, Fan LF, Rong MZ, Zhang MQ, Gao YM (2019) External Stress-Free Reversible Multiple Shape Memory Polymers. ACS Appl Mater Interfaces 11:31346–31355
Nie J, Huang J, Fan J, Cao L, Xu C, Chen Y (2020) Strengthened, Self-Healing, and Conductive ENR-Based Composites Based on Multiple Hydrogen Bonding Interactions. ACS Sustain Chem Eng 8:13724–13733
Zheng Y, Ji XY, Yin M, Shen JB, Guo SY (2017) Strategy for Fabricating Multiple-Shape-Memory Polymeric Materials via the Multilayer Assembly of Co-Continuous Blends. ACS Appl Mater Interfaces 9:32270–32279
Yang G, Wan X, Liu Y, Li R, Su Y, Zeng X, Tang J (2016) Luminescent Poly(vinyl alcohol)/Carbon Quantum Dots Composites with Tunable Water-Induced Shape Memory Behavior in Different pH and Temperature Environments. ACS Appl Mater Interfaces 8:34744–34754
Teng J, Wang Z, Liu J, Sun X (2020) Effect of dynamic vulcanization system on the thermodynamics and shape memory properties of TPI/HDPE hybrid shape memory polymers. Eur Polymer J, 132
Scalet G, Niccoli F, Garion C, Chiggiato P, Maletta C, Auricchio F (2019) A three-dimensional phenomenological model for shape memory alloys including two-way shape memory effect and plasticity. Mech Mater, 136
Liu J, Wang Z, Li S, Teng J, Min B (2019) Development of functionalized core-shell nanohybrid/synthetic rubber nanocomposites with enhanced performance. Soft Matter 15:8338–8351
Liu J, Wang Z, Li S, Li S (2019) Development of trans-1,4-polyisoprene (TPI) nanocomposite reinforced with nano-SiO 2 functionalized graphene oxide. Colloids Surf a-Physicochemical Eng Aspects, 580
Qi X, Pan C, Zhang L, Yue D, Bio-Based (2023) Self-Healing, Recyclable, Reconfigurable Multifunctional Polymers with Both One-Way and Two-Way Shape Memory Properties. Acs Applied Materials & Interfaces
Fu X, Yuan Y, Liu Z, Yan P, Zhou C, Lei J (2017) Thermoplastic shape memory polymers with tailor-made trigger temperature. Eur Polymer J 93:307–313
Wang Y, Geng J, Xia L, Xin Z (2018) Multiple shape memory behaviors of natural Eucommia ulmoides rubber and polybutene-1 composites. Polym Int 67:901–908
Tian M, Gao W, Hu J, Xu X, Ning N, Yu B, Zhang L (2020) Multidirectional Triple-Shape-Memory Polymer by Tunable Cross-linking and Crystallization. ACS Appl Mater Interfaces 12:6426–6435
Guo J, Wang Z, Tong L, Lv H, Liang W (2015) Shape memory and thermo-mechanical properties of shape memory polymer/carbon fiber composites. Compos Part a-Applied Sci Manuf 76:162–171
Liu J, Teng J, Yun K, Wang Z, Sun X (2019) Investigation of thermodynamic and shape memory properties of alumina nanoparticle-loaded graphene oxide (GO) reinforced nanocomposites. Mater Design, 181
Liang J-Z (2019) Melt strength and drawability of HDPE, LDPE and HDPE/LDPE blends. Polym Test 73:433–438
Yao P, Wu H, Ning N, Zhang L, Tian H, Wu Y, Hu G, Chan TW, Tian M (2016) Properties and unique morphological evolution of dynamically vulcanized bromo-isobutylene-isoprene rubber/polypropylene thermoplastic elastomer. RSC Adv 6:11151–11160
Xu C, Fan J, Yuan D, Wang Y, Chen Y (2019) Model construction of particle size in dynamic vulcanization of PVDF/SR blends-matching degree between crosslinking and shearing rates. Mater Chem Phys 222:200–206
Xia L, Gao H, Bi W, Fu W, Qiu G (2019) Z. Xin, = Shape Memory Behavior of Carbon Black-reinforced Trans-1,4-polyisoprene and Low-density Polyethylene Composites. Polymers, p 11
Zhang JC, Xue ZH (2011) A comparative study on the properties of Eucommia ulmoides gum and synthetic trans-1,4-polyisoprene. Polym Test 30:753–759
Song YM, Zhao ZD, Yu WX, Zheng WT, Li B, Yang XW, Chen XF (2008) Poly(vinylidene fluoride)/clay nanocomposites by melt compounding. Chem Res Chin Univ 24:116–119
Wang Q, Ma Y, Meng J, Liu X, Xia L (2022) Thermal-triggered Trans-1, 4-polyisoprene/polyethylene wax shape memory and self-healing composites. Polym Test, 111

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Research on Shape Memory Performance of TPI/PE Composite Materials

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Abstract

Figures

1. Introduction

2. Experimental

2.1. Materials and preparation

2.2 Performance testing

3 Results and discussion

3.1 Vulcanization characteristics

3.2 Mechanical properties

3.3 Crystallization properties

3.4 Microstructural characterization

3.5 Shape memory properties

4 Conclusions

Declarations

References

Additional Declarations

Supplementary Files

Status:

Version 1