High-elastic State Research Articles

Smart Window with Reversible and Instantaneous Photoluminescence based on Microsphere Structure.

A smart window that dynamically regulates light transmittance is crucial for modern life end-users and promising for on-demand optical devices. The advent of three-dimensional (3D) photonic crystal microspheres has enriched the functions of a smart window. However, the smart window formed by polymer microspheres encounters poor mechanical strength and microstructural defects. Herein, to solve this limitation, we report the microsphere-based smart window composed of tightly packed cross-linked polymer microspheres (as a precursor) containing organic photochromic dyes, followed by compression under a high elastic state. When excited under an ultraviolet supply, our smart window showed a rapid and reversible fluorescent photoluminescence without fatigue (50 cycles). Moreover, the bulk devices with a microsphere cross-linked network structure enable excellent mechanical strength (hardness reached 0.158 GPa) and visible-light transparency. Interestingly, a QR code can be recognized under visible light exposure but not under ultraviolet light exposure because of photoluminescence of the smart window. Our method generally provided a paradigm for various amorphous polymers, which can be regarded as a simple and effective approach to build a versatile strategy to introduce an ideal marketplace with economic and community benefits.

Research on thermal insulation materials properties under HTHP conditions for deep oil and gas reservoir rock ITP-Coring

Deep oil and gas reservoirs are under high-temperature conditions, but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability, resulting in distorted resource assessments. The development of in situ temperature-preserved coring (ITP-Coring) technology for deep reservoir rock is urgent, and thermal insulation materials are key. Therefore, hollow glass microsphere/epoxy resin thermal insulation materials (HGM/EP materials) were proposed as thermal insulation materials. The materials properties under coupled high-temperature and high-pressure (HTHP) conditions were tested. The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased; additionally, increasing temperature accelerated the process. High temperatures directly caused the thermal conductivity of the materials to increase; additionally, the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity. High temperatures weakened the matrix, and high pressures destroyed the HGM, which resulted in a decrease in the tensile mechanical properties of the materials. The materials entered the high elastic state at 150 °C, and the mechanical properties were weakened more obviously, while the pressure led to a significant effect when the water absorption was above 10%. Meanwhile, the tensile strength/strain were 13.62 MPa/1.3% and 6.09 MPa/0.86% at 100 °C and 100 MPa, respectively, which meet the application requirements of the self-designed coring device. Finally, K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100 °C and 100 MPa. To further improve the materials properties, the interface layer and EP matrix should be optimized. The results can provide references for the optimization and engineering application of materials and thus technical support for deep oil and gas resource development.

Study on the preparation method of porous membranes with single pore size distribution and tailored pore sizes by the induced swelling effect of pre-set graft side chains

To improve the sieving accuracy of material separation, it is necessary to develop a porous membrane with tailored pore size and narrow pore size distribution. Polyvinylidene fluoride (PVDF), the mainstream membrane material, is a semi-crystalline polymer. On the basis of the high elastic state of the PVDF molecular chain in the amorphous region at room temperature, a novel method was proposed to prepare porous membranes with single pore size distribution and tailored pore sizes in this paper. First, 1,3-bis (tris(hydroxymethyl)methylamino) propane (Bis-Tris propane) was grafted onto the PVDF-CTFE main chain during casting solution preparation, and the membranes with the thin and nonporous skin layers were prepared by non-solvent-induced phase separation (NIPS), which had almost no water flux. The membrane with the nonporous skin layer produced a water flux of 35.3 L ∙ m−2∙ h−1∙ bar−1 after soaking in the alkaline glycine solution. FTIR and EDX tests demonstrated that small molecular glycine can be guided into the membrane matrix by the affinity with the polar groups on the pre-set side chains, inducing the reactive swelling effect, which led to the formation of new through holes. Subsequently, the membrane with the nonporous skin layer was initially soaked in ethanol to form pores in advance, then the induced reactive swelling of pre-set graft side chains was carried out. The water flux of obtained membrane was significantly up to 96.9 L ∙ m−2∙ h−1∙ bar−1, proving that the pre-pore forming process successfully strengthened the reactive swelling-caused pore generation effect. Furthermore, based on the enhanced swelling-caused pore generation strategy, amino acids with different molecular sizes were induced to the reactive swelling effect in the amorphous regions. The mathematical fitting showed a linear correlation between the average pore size of the membrane and the molar hydration volume of amino acids, and the membrane was single pore size distribution, verifying that controllably tailored membrane pore size can be realized by the reactive swelling effect of the reactive small molecule with different molecular sizes. Compared to some membranes with single pore size distribution prepared by track etching and anodic oxidation method, the membranes prepared by this method had higher water flux. The water contact angle result clarified that the membrane surfaces and pore channels had excellent hydrophilicity. The reactive swelling did not change the crystallinity and porosity, so the mechanical strength of the membrane did not deteriorate.

Особливості розроблення піроболтів з низькими ударними та віброімпульсними характеристиками

One of the systems in the integrated launch vehicle responsible for prelaunch processing and launch is a ground thermal conditioning system, which supplies the low-pressure air into the launch vehicle’s “dry” compartments. Thermal conditioning system is mated with the launch vehicle, using the mating interfaces, proper functioning of which enhances reliability of the ground support equipment, the launch vehicle and the entire space launch system. The article describes key requirements to the interfaces of the thermal conditioning system and the drawbacks of the existing designs. The article proposes a new design concept of the interface that connects the pipeline of the ground thermal conditioning system to the orifice of the launch vehicle using the corrugated rubber hose composed of three basic parts, attached with the help of a metal lock/release assembly. The proposed solution provides reliable leaktightness, ease of operation, providing multiple connections to the launch vehicle, including at various angles, and automatic disconnection by rocket motion or manual removal in case of launch abort. Using rubber as a high-elasticity structural material to manufacture the hoses, enabled minimization of efforts required to disconnect the interface from the launch vehicle. In its high-elasticity state, rubber can absorb and dissipate mechanical energy within a wide range of temperatures, which prevents transmission of engine vibrations to the ground thermal conditioning system. The article presents key properties of rubber used as a structural material and its peculiarities to be considered during design of similar products. Unlike metal showing two types of deformation (elastic and plastic), rubber can exhibit three types of deformation (elastic, superelastic and plastic). In the process of interface design, we took into account two types of deformations (elastic and superelastic ones). Experimental studies of the interface showed its full compliance with technical specification. Key words: orifice of the launch vehicle, corrugated rubber hose, lock/release assembly, superelastic deformation, leaktightness.

Highly Efficient Dispersion of Individual Multiwalled Carbon Nanotubes by Polylactide in High Elastic State

Highly Efficient Dispersion of Individual Multiwalled Carbon Nanotubes by Polylactide in High Elastic State

Laboratory evaluation on oil-soluble resin as selective water shut-off agent in water control fracturing for low-permeability hydrocarbon reservoirs with bottom aquifer

During the development of low-permeability hydrocarbon reservoirs with bottom aquifer, hydraulic fracturing is essentially employed for commercial oil flow while increasing the potential risk of serious water production, thus water control hydraulic fracturing technology plays important role on addressing this challenge. In this work, a water control fracturing technique is developed to integrate fracture height containment with selective water shut-off. Specifically, oil-soluble resin is used as selective water shut-off agent and is injected with sinking agent simultaneously, carried by fracturing fluid at the fracture generation stage, to establish an improved artificial barrier. Afterwards, a modified fracture conductivity test equipment is designed and manufactured to measure the selective conductivity of the artificial barrier, its sensitivity to temperature, ratio of oil-soluble resin to sinking agent, two-phase flow are studied to evaluate the capability of selective water shut-off.The results demonstrated that 1) the occupation in porous space of sinking agent (0.212–0.425 mm) and the status change from glassy state to high elastic state of oil-soluble resin are mainly responsible for water shut-off; 2) The ratio of oil-soluble resin to sinking agent in 10 g: 70 g and temperature at 75 °C are two critical value to significantly reduce water conductivity in our experiments; 3) Fast dissolution of resin in oil results in oil conductivity over 5 to 100 times higher than water conductivity to achieve selective water shut-off. The results presented herein will provide important guidance on water control in low permeability reservoirs with active bottom aquifer and will promote the unconventional hydrocarbon recovery.

High strain-rate compression behavior of woven CF/PEEK thermoplastic composites at the glassy state and high-elastic state

A reliable hot air-flow heating approach is creatively carried out for high strain rate tests without environment tank. The out-of-plane and in-plane compression of carbon fiber reinforced polyetheretherketone (CF/PEEK) woven composites are investigated from 400 to 4000/s at the glassy state and high-elastic state. The real-time and in-situ deformation and failure process of the composite specimens under the extreme thermo-mechanical loads are successfully captured, which can reflect the impact dynamic behavior of the material near the ultimate service temperature. Empirical laws for mechanical index of the woven composites are given. The results reveal that the thermal softening effect outperforms the strain-rate strengthening effect. For out-of-plane impact at low strain rates, damage mode transitions from the interface and matrix cracking at glassy state to the “parallel” shear and fiber extrusion at high-elastic state. Under high strain rates, it reveals the “fragmented” shear mode at glassy state. For in-plane impact, the temperature effect leads to the failure mode changing from the delamination and local shear to the mixed feature of kinking bands, delamination, and multiple-band shear with “bulge” behavior. And the multiple-band shear and delamination are more likely to occur along the in-plane direction as the strain rate increased.

In Situ Constructed Nanocrystal Structure and Its Contribution in Shape Memory Performance of Pure Polylactide

Crystal size plays an essential role in the performance of polymers. Generally, direct processing of common spherulites into nanocrystals (NCs) is hardly applied since polymer spherulites always shape into fibrous crystals and are hard to flow again. In this study, polylactide (PLA) lamellae of spherulites are first diluted by amorphous PLA. Then, PLA NCs are constructed in situ by intense stress, which is transferred by the amorphous polylactide in a high elastic state. The NCs and their network formed in bulk endow pure polylactide with excellent shape memory features. A strong shape recovery initiation force (around 4–5 MPa) and an enhancement of 41.6% in the shape recovery ratio with 30 wt % NCs in PLA are achieved compared with traditional PLA. This study presents a new common methodology for the industrial production of polymer NCs.

Free volume dependence of the dielectric constant of poly(vinylidene fluoride) nanocomposite films.

The free volume effects on the dielectric properties of the polymer are ambiguous, and the quantitative effect of free volume on the dielectric properties has rarely been systematically studied, especially in the high-elastic state dipolar (HESD) polymer. In this work, the free volume of dipolar poly(vinylidene fluoride) (PVDF) is regulated by the addition of Al2O3, which greatly increase the size of free volume holes. Then the effect of free volume on the dielectric properties of PVDF/Al2O3 composites is discussed. The greatly enlarged size of free volume holes is believed to potentially generate disparate effects on dielectric constant under different frequencies in such kinds of HESD polymer-based composites, bringing about more remarkable frequency dependence of the dielectric constant. The influence of atomic-scale microstructure based on free volume further clarifies the free volume effects on the dielectric properties and provides valuable insights for the research of dielectric behaviour of polymer composites, which is constructive to design novel dielectric materials and further optimize the dielectric properties of dipolar dielectric polymer composites.

Efficient liberation of electrode materials in spent lithium-ion batteries using a cryogenic ball mill

Efficient liberation is a key to the recycling of the electrode materials in spent lithium-ion batteries (LIBs). To improve the liberation of the electrode materials, a novel cryogenic grinding method of high selectivity was proposed. The low temperature characteristics of the traditional binder material PVDF and the current collector materials were tested. The results show that the glassy transition temperature of the binder PVDF is about 235 K. The binder would change from a high elastic state to a brittle state thus is easy to be crushed at a lower temperature. On the contrary, the impact strength of the current collector materials increases with the decrease of the temperature. Therefore, the grinding of electrode plates at low temperatures would be more selective grinding. The cryogenic grinding tests results show that, compared with that of room temperature, the content of the nickel-cobalt-manganese-lithium in the −0.15 mm particle size was increased from about 16–84%, the graphite content from 31.55% to 90.58%, and the content of aluminum and copper in the +1 mm grain size increased from 79.32% and 74.62–95.42% and 97.75%，respectively. This research may provide a new method to the recycling of spent LIBs.

Evolution of ordered structure of TPU in high-elastic state and their influences on the autoclave foaming of TPU and inter-bead bonding of expanded TPU beads

Different from the melt foaming of extrusion and injection molding, polymer is in high-elastic state during autoclave foaming. In this study, the critical parameters used to describe the high-elastic state of polymer, i.e., softening temperature (Ts) and viscous flow temperature (Tv), were introduced to explain the autoclave foaming of thermoplastic polyurethane (TPU) and the inter-bead bonding mechanism of expanded TPU (ETPU) beads. Evolution of ordered structure of TPU in high-elastic state was characterized by different methods. The steam-chest molding was used to manufacture the ETPU parts, and the molding temperature window was compared with the Ts and Tv of TPU resin, and the endothermic peaks of ETPU beads. The melting of ordered hard segments structure, interface-diffusion of polymer chains, cooling-induced formation of new ordered structure among the diffused polymer chains were the possible mechanism of strong inter-bead bonding in the molded ETPU parts.

Гума як перспективний конструкційний матеріал для створення вузлів стикування системи термостатування

In integrated launch vehicles, one of the systems responsible for successful launch preparation and support is a ground thermal conditioning system supplying low-pressure thermostatic air to the “dry” compartments and head blocks of a launch vehicle. To connect the thermal conditioning system to the launch vehicle, a special interface is used. The proper functioning of the interface is critical to the reliability of the ground equipment of the system, the launch vehicle, and the space complex as a whole. This article describes key requirements to the interfaces of the thermal conditioning system and the drawbacks of their existing designs. The article proposes a new concept of interface design, according to which the pipeline of the ground thermal conditioning system is connected to the inlet tube of the launch vehicle via a corrugated rubber hose composed of three basic parts. The hose is attached to the inlet tube of the launch vehicle with the help of a metal lock/unlock device. The proposed solution provides good air tightness, ease of operation, easy multiple connections to the launch vehicle at different angles, and an automatic disconnection at launch or a manual disconnection in the case of a cancelled launch. Using rubber, which is a high-elasticity structural material, in the manufacturing of hoses makes it possible to minimise the effort required to disconnect the interface from the launch vehicle. In a high elasticity state, rubber can absorb and dissipate mechanical energy over a wide range of temperatures, which precludes the vibration caused by the engine operation from being transmitted to the ground thermal conditioning system. The article presents the key properties of rubber used as a structural material and its features to be considered in the design of similar devices. In contrast to metal, which shows two types of deformation (elastic and plastic), rubber can exhibit three types (elastic, superelastic, and plastic). During the design of interfaces, two types of deformation were taken into account: elastic and superelastic. Experimental tests of the interface presented in the article showed its full compliance with the requirements specification.

The effect of surface hydroxylation of Nano-SiO2 on the insulating paper cellulose/Nano-SiO2 interface

It has become an important method to modify cellulose insulating paper by doping nano-SiO2 particles to improve its thermal stability. But in the doping process, the pure nano-SiO2 surface can easily react with oxygen and produce hydroxyl groups. The influence of interface hydroxylation is difficult to be explained in macroscopic experiments. Therefore, in this paper, the surface hydroxylated nano-SiO2/cellulose bilayer model and the unhydroxylated nano-SiO2/cellulose bilayer model were established by means of molecular simulation. The interface change before and after hydroxylation was analyzed from the microscopic parameters such as model interface interaction energy, interface relative concentration, cellulose chain mean square displacement and interface hydrogen bond. The result of research shows: compared with the N–C (unhydroxylated) bilayer model, the interaction energy and interaction energy density of the SNH–C (hydroxylated) bilayer model were increased to 2.3 times and 2.2 times respectively. Furthermore, the overlapping area and peak value of interfacial relative concentration increased to 1.62 times and 1.24 times respectively, the mean square displacement (MSD) jumping temperature of cellulose decreased by 20 K, and a hydrogen bond network with a density of 4.18 nm−2 was formed between the interfaces. Obviously, the surface hydroxylation of nano-SiO2 helps to promote the interaction between the interfaces, so that the nano-SiO2 and cellulose bond becomes more closely, which helps to strengthen the constraint of cellulose chain, and delays the process of transition from glassy state to high elastic state.

Tribological behaviour of acrylonitrile-butadiene rubber under thermal oxidation ageing

Acrylonitrile–butadiene rubber (NBR) is an important tribological material that is often used in dynamic sealing pairs (as rubber/metal seal-pairs), but often degrades prematurely because of thermal oxidation ageing. In this work, NBR seals were exposed to an accelerated thermal ageing atmosphere at different temperatures and time periods, and the aged NBRs were evaluated for their mechanical properties, tribological behaviour, and energy dissipation. The results showed that thermal oxidation ageing has a substantial effect on rubber properties. The hardness and bulk modulus of rubber increased, whereas its tensile strength and tear strength decreased remarkably with increasing ageing temperature and time. The evolution trends of rubber ageing can be divided into three regions (A, B, and C) according to different ageing degrees (high elastic state, weakened elastic state, and hardening state). The damage mechanism of each region is obviously different. The wear mechanism gradually changes from adhesive wear to abrasive wear, or fatigue and abrasive wear. Although the average wear rate decreases with the increase of ageing parameters, mechanical properties, such as viscoelasticity, fracture resistance, and tear resistance, were severely reduced or even disappeared. The adhesion and hysteresis characteristics of the rubber during friction were remarkably disturbed because of their ageing degradation. Therefore, different energy dissipation characteristics in friction were presented for various aged rubbers.

Упруго-релаксационные свойства древесины лиственницы и их роль при получении древесных и древесно-угольных брикетов

Processing of sawdust, which accounts for 10…12 % of the volume of processed raw wood materials in products with high added value, is one of the areas of woodbiorefining. This became a premise for sawdust processing into secondgeneration biofuel, as well as carbonized briquettes based on it. The relaxation properties of larch wood are studied and their role in the technological process carried out in creation of new generation biofuel with a given set of operational properties is analyzedtaking into account the specific features of relaxation transitions at the stages of obtaining wood and charcoal briquettes.The relationship between the directed change in the relaxation state of the wood polymer components (lignin, cellulose and hemicelluloses) and the operational parameters is considered. The experimental data findings confirm that cellulose and hemicelluloses are in a high-elastic state in the initial wood and sawdust.It is advisable to ensure that the wood polymer components are transferred below the brittle temperature, in other words, wood should be dried to the lowest possible residual moisture, in order to grind wood sawdust to a powdery state with minimum energy consumption. Subsequent steam humidification to a moisture content of 3…4 % gives the system extrusion ability due to the formation of hemicellulose gel layers on the surface. For citation: Pekarets A.A., Erokhina O.A., Novozhilov V.V., Mandre Yu.G., Akim E.L. Elastic and Relaxation Properties of Larch Wood and Their Role in Production of Wood and Charcoal Briquettes. Lesnoy Zhurnal [Russian Forestry Journal], 2020, no. 1, pp. 200–208. DOI: 10.37482/0536-1036-2020-1-200-208

Molecular mobility in crystallising aromatic thermoplastic polyimide R-BAPS

The molecular mobility of the thermoplastic aromatic R-BAPS polyimide films based on 1,3-bis (3,3’-4,4’-dicarboxyphenoxy) benzene (dianhydride) and 4,4’-bis (4-aminophenoxy) biphenyl was studied using the dielectric method. Two relaxation regions of dipole polarisation caused by local mobility of phenylene groups in the diamine (γ process) and in the diamine and dianhydride macromolecule parts (β process) were identified in the glassy state, In the high-elastic state, two relaxation processes, α and αMWS, were also observed. The α process is due to the large-scale segmental mobility of macromolecules. The αMWS process is caused by the relaxation at the boundary between amorphous and crystalline regions, i.e., the Maxwell-Wagner-Sillars relaxation. Moreover, a structural transition due to melting was observed in the initial samples.

Poly(4-methyl-1-pentene) as a semicrystalline polymeric matrix for gas separating membranes

The appearance of gas (vapor) membrane separation technologies stimulates the expansion of the boundaries of the existing membrane material applications. One of these materials is commercially available poly(4-methyl-1-pentene) (PMP). This paper presents results of a theoretical and experimental study of selective gas transfer in PMP with varying degrees of crystallinity. In this study, the experimental measurements of selective gas transfer were carried out in the range of temperatures covering the glassy and high-elasticity state of the amorphous PMP phase. Pierotti's theory was used to estimate the solubility coefficients of ethane in the crystalline and amorphous PMP phases. The diffusion (D), solubility (S), and permeability (P) coefficients of the amorphous and crystalline PMP phase with respect to lower alkanes were determined for the first time. It was shown that the PMP crystalline phase is selectively permeable to gases with the properties, that are close to those of the amorphous phase below the Tg. It can be concluded that the crystalline phase “works” according to the solution–diffusion model and makes a significant contribution to the gas permeability of PMP. It is noted that the PMP crystalline phase has high selectivity for C1–C4 alkane separation.

EFFECT OF HYBRID CARBON BLACK/CARBON NANOTUBES FILLER ON VULCANIZATES RELAXATION BEHAVIOR

The glass transition in hybrid carbon black/carbon nano-tube (CB/CNT) filled elastomer composites has been studied through dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The storage modulus E' and loss tangent (TanD) are recorded from -100 to 100 ° C and a frequency of 10 Hz. The thermal analysis was carried out at 2° C/min temperature increment. The vulcanizates were made as per conventional technology. The CNT were introduced into rubber compounds as CB/CNT masterbatches resulting from joint ultrasound processing. The CNT content in the rubber compounds varied from 0.1 to 0.5 phr. The DMA data proved that introduction of CB/CNT hybrid particles resulted in the spread of TanD temperature peaks for all the samples towards lower temperatures and the subsequent shift of the maximum TanD position by 4.0 to 15.6 degrees. The DSC data demonstrated the existence of additional low-temperature α-relaxation transitions in the modified vulcanizates (-123…-118 °C). The observed relaxation behavior could be explained by the increase in vacant volume in the vulcanizates along with the rise in segmental mobility of some macromolecules when compared against the reference sample. The highest hybrid filler content vulcanizate demonstrated certain TanD drop in the glass-to-rubber transition zone and the TanD rise in the high-elasticity state, which fact indicated formation of additional filler-filler interactions. Thus, the CNT treatment with carbon black resulted in a synergy effect upon the rubbers' dynamic characteristics; hence, it can be applied to the task of raising the material frost resistance point.

PROPERTIES OF DYNAMIC THERMOPLASTIC ELASTOMERS BASED ON POLYPROPYLENE AND BUTADIEN-NITRIL RUBBER

The study results of the influence of butadiene-nitrile rubber different grades concentration, cross-linking agent type and content on the physico-mechanical and thermo-deformation properties of polymer compositions based on polypropylene are presented. Mixing of the components was carried out on hot rollers in the melt mode at 170 °C. A preliminary study of rubber concentration affect on the properties of compositions based on polypropylene showed that the introduction of an elastomeric component leads to a regular decrease in the strength and elongation at break of the compositions. The results of investigation of the thermo-deformation properties of polymer compositions showed that at a rubber concentration of 30wt%, and higher on thermomechanical curves, the region of the high-elastic state characteristic of rubbers is noticeably distinguished. Taking into account that the rubber materials are obtained during the process of their vulcanization, it seemed interesting to crosslink materials with two types of vulcanizing agents – dicumyl peroxide and sulphur for obtaining comparable results. The concentration of dicumyl peroxide was varied between 0.5 - 2.0 wt%. It was found that the use of dicumyl peroxide in an amount of 1.0-2.0 wt% is accompanied by intense occurrence of crosslinking with the formation of an irreversible highly crosslinked structure in the polymer composition. Based on the evaluation of the melt flow index of the vulcanized compositions, it was found that at the concentration of dicumyl peroxide in an amount of 0.5 wt% they still retain the ability to flow. At concentrations above 0.5 wt% of dicumyl peroxide the polymer compositions completely lose the fluidity of the melt. It was found that with an increase in the sulphur concentration from 3.0 to 10 wt% the decrease in the melt flow index from 2.76 to 0.616 g/10 min is observed. It was found that the crosslinking process predominantly proceeds through double bonds of butadiene-nitrile rubber, thereby facilitating the production of dynamically vulcanized polymer materials with a unique combination of structure and properties. This was confirmed by the results of a study of the thermo-deformation characteristics of compositions, according to which a transition from the region of a high-elastic state to viscous-flow state is observed in all samples subjected to sulfur vulcanization. The results of the study make it possible to state that dynamic thermoplastic elastomers can be obtained only if the ratio of the components used in the polymer composition is correctly selected.

The study of gas X (X=H2O, CH4, O2) adsorbed low density poly(4-methyl-1-pentene) foam by molecular dynamics simulations

We use the molecular dynamics (MD) simulations to study the important properties of gas X (X = H2O, CH4, O2) adsorbed-poly(4-methyl-1-pentene) (PMP) and our results clarify that the H2O and CH4 molecules can increase the glass transition temperature (Tg) of PMP while O2 molecules can decrease the Tg of PMP. Moreover, all the jump values of MSD for pure PMP and gas-adsorbed PMP fall behind the corresponding Tg and demonstrate the hindrance of the chain segment motion is reduced at high elastic state. In addition, the calculated Young's modulus (E), Bulk modulus (K), Shear modulus (G) and Poisson's ratio (γ) indicate the CH4-adsorbed PMP system has a remarkable mechanical property and the K/G and Cauchy pressure (C12−C44) also present it has an outstanding ductility. Therefore, CH4-adsorbed PMP foam is considered as a promising candidate target in ICF experiment.