橡胶型乙烯-醋酸乙烯酯共聚物与热塑性聚氨酯弹性体共混物耐油性能研究

将2种乙烯-醋酸乙烯酯共聚物（EVM400，EVM700）和2种热塑性聚氨酯弹性体（聚酯型TPU385E和聚醚型TPU8685）按不同并用比进行交叉共混，考察了共混体系的耐油性能。结果表明，3#标准油较1#标准油对EVM／TPU共混胶性能影响大，且VA含量低的EVM400共混胶比VA含量高的EVM700共混胶受3#标准油的影响大；EVM700／TPU385E共混胶具有最好的耐油性；EVM／TPU共混胶并用比为50／50时．浸油前后性能变化最大，即耐油性最差。     

TOTM/DOP并用比对CM/EVM共混胶性能的研究

本文主要研究了CM/EVM为70/30配比时,不同TOTM/DOP配比下共混胶料的力学性能、耐热氧老化性能、耐油性能。结果表明:随着TOTM用量的增加,热空气老化前,拉伸强度增大,扯断伸长率基本不变,100%定伸应力呈逐渐上升的趋势;热空气老化后,拉伸强度逐渐下降,扯断伸长率增大,50%定伸应力逐渐减小。在3#标准油中老化后,扯断伸长率呈下降趋势,100%定伸应力增大,拉伸强度增大,体积变化率减小。     

动态硫化乙华平橡胶/热塑性聚氨酯弹性体共混物

对乙酸乙烯酯质量分数分别为40%和70%的乙烯-乙酸乙烯酯共聚物EVM 400和EVM 700先进行动态硫化制成母炼肢,然后与热塑性聚氨酯弹性体(TPU)进行共混,以过氧化二异丙苯(DCP)作为硫化荆.考察了动态硫化工艺和DCP用量以及返炼对共混物力学性能的影响,并通过相差显微镜对共混物的结构进行了分析.结果表明,EVM 400在动态硫化时,黏度变化对DCP用量改变的敏感性要明显高于EVM 700;随着DCP用量的增大,共混物TPU/EVM 700的力学性能提高,而对TPU/EVM 400共混物的力学性能没有明显改善;EVM动态硫化后,在TPU/EVM 700共混物中,其相畴较TPU/EVM400共混物的更小.更均匀;返炼使TPU/EVM 700共混体系的力学性能下降,但使TPU/EVM 400共混体系的力学性能有所提高.     

DCP/TAIC用量及老化行为对NBR/EVM共混胶性能的影响

课题研究了DCP/TAIC用量及不同老化行为对NBR/EVM共混胶的硫化特性、总交联密度、两项交联密度、物理机械性能、压缩永久变形及压缩蠕变等性能的影响;结果表明共混胶随着DCP/TAIC用量增大,其总交联密度、两项交联密度、拉伸强度、100%定伸应力、硬度和压缩蠕变呈上升趋势,扯断伸长率和压缩永久变形呈上升趋势;老化后总交联密度、两相交联密度、100%定伸应力、硬度和老化前相比都增大,拉伸强度和扯断伸长率都减小,老化前后扯断永久变形基本不变。     

硫化剂双酚AF和DCP对EPDM/FKM共混胶性能影响

研究了硫化剂双酚AF和DCP用量对EPDM/FKM共混胶硫化特性和热空气老化前后物理机械性能的影响。实验证明,随着双酚AF用量的增加,共混胶M_H变大,t_(10)基本不变,t_(90)变大;硬度和扯断伸长率基本不变,拉伸强度和100%定伸应力均变大;老化后,硬度和100%定伸应力变大,拉伸强度和扯断伸长率变小。随着DCP用量的增加,共混胶M_H变大,t_(10)基本不变,t_(90)变小;硬度基本不变,拉伸强度先上升后下降,100%定伸应力变大,扯断伸长率下降;老化后,硬度和100%定伸应力变大,拉伸强度和扯断伸长率均变小。     

EVA/TPU共混物热氧老化性能研究

研究4种不同组合的乙烯-乙酸乙烯酯共聚物（EVA）／热塑性聚氨酯（TPU）共混物热氧老化前后物理性能的变化规律。结果表明，EVA／TPU共混物老化后总体趋势是邵尔A型硬度、100％定伸应力和拉伸强度增大，拉断伸长率减小；在EVA／聚醚型TPU（T8）并用比为50／50时，共混物老化后出现气泡，老化规律异常。乙酸乙烯酯质量分数为0．4的EVA（E4）／T8共混物在E4／T8并用比为75／25时，老化前后平均的物理性能变化率较小，为较佳组合。     

CM/EVM共混胶补强体系的研究

研究了CM/EVM为70/30配比下的补强体系。结果表明:随N550含量的减小,CM/EVM共混胶拉伸强度减小,断裂伸长率减小。耐油老化和热空气老化后,随强威粉用量的增多,共混胶拉伸强度、扯断伸长率、100%定伸应力呈现规律性变化。CM并用了EVM后,CM/EVM共混胶的性能有了较大提高。     

SEBS共混物的力学性能研究

采用熔融共混法研究了白油、聚丙烯(PP)、聚苯乙烯(PS)和无机填料对氢化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)共混物力学性能的影响。结果表明,白油使SEBS共混物的300%定伸应力、扯断强度、硬度迅速下降,扯断伸长率升高;随着PP加入量的增加,SEBS共混物的300%定伸应力、扯断强度和硬度均逐渐升高,扯断伸长率逐渐下降;随着PS加入量的增加,SEBS共混物的300%定伸应力、硬度逐渐升高,扯断伸长率逐渐降低,而扯断强度先降低后升高;无机填料对SEBS共混物的力学性能影响较大,应根据制品性能要求选择合适的填料种类及加入量,以达到SEBS最优化的配方设计。     

复合硫化体系下NBR/EVM共混胶耐热空气及耐油性能研究

在复合硫化体系作用下,研究了NBR/EVM(EVM800HV和EVM500HV)共混比对硫化胶硫化特性、物理机械性能、热空气老化性能和热油老化性能的影响。结果表明,随EVM用量的增大,NBR/EVM硫化胶的交联密度逐渐减小,Ts1逐渐增大,胶料的操作安全性逐渐变好,T90逐渐增大;拉伸强度和300%定伸应力逐渐减小,且NBR/EVM500HV硫化胶减小更显著,硬度和100%定伸应力略微减小,NBR/EVM500HV硫化胶的扯断伸长率随EVM500HV用量增大逐渐增大,NBR/EVM800HV硫化胶的扯断伸长率随EVM800HV用量增大而基本保持不变。     

HNBR/FKM共混比对HNBR共混胶力学性能及耐热油性能的影响

研究了HNBR/FKM共混比对HNBR共混胶力学性能及耐热油性能的影响,研究表明,随着HNBR/FKM共混胶中氟橡胶共混比的增加,共混胶的硫化程度先增大后基本不变,硫化时间变长;共混胶100%定伸应力上升,硬度变大,拉伸强度先变大后变小,扯断伸长率减小;经热空气老化后,共混胶硬度明显变大,拉伸强度变大但比老化前小,扯断伸长率减小;经热油老化后,共混胶硬度变大且比老化前大,拉伸强度变大但比老化前小,扯断伸长率也降低,50%定伸应力变大,质量变化率和体积变化率为负值,且绝对值变大;共混胶的耐低温性能变差。     

DMA analysis of the damping of ethylene–vinyl acetate/acrylonitrile butadiene rubber blends

The mechanical and damping properties of blends of ethylene–vinyl acetate rubber (VA content > 40% wt) (EVM)/acrylonitrile butadiene rubber (NBR), with 1.4 phr BIPB [bis (tert‐butyl peroxy isopropyl) benzene] as curing agent, were investigated by DMA and DSC. The effect of chlorinated polyvinyl chloride (CPVC), silica, carbon black, and phenolic resin (PF) as a substitute curing agent, on the damping and mechanical properties of EVM/NBR blends were studied. The results showed that 10 phr CPVC did not contribute to the damping of EVM700/NBR blends; Silica could dramatically improve the damping of EVM700/NBR blends because of the formation of bound rubber between EVM700/NBR and silica, which appeared as a shoulder tan δ peak between 20 and 70°C proved by DMA and DSC. This shoulder tan δ peak increased as the increase of the content of EVM in EVM/NBR blends. The tensile strength, modulus at 100% and tear strength of the blend with SiO₂ increased while the elongation at break and hardness decreased comparing with the blend with CB. PF, partly replacing BIPB as the curing agent, could significantly improve the damping of EVM700/NBR to have an effective damping temperature range of over 100°C and reasonable mechanical properties. Among EVM600, EVM700, and EVM800/NBR/silica blend system, EVM800/NBR/silica blend had the best damping properties. The EVM700/NBR = 80/10 blend had a better damping property than EVM700/NBR = 70/20. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

NBR/EVM并用胶料的性能研究

文中主要研究了NBR/EVM(丁腈橡胶/乙烯醋酸乙烯酯)不同配比共混胶料的力学性能、耐老化性能、耐油性能、耐低温性能,耐高温性能和硫化特性.结果表明,随着EVM含量的增加,NBR/EVM硫化胶的拉伸强度、拉断伸长率、回弹性和压缩永久变形有明显改善,硬度和100％定伸应力呈下降趋势;脆性温度明显降低,显著改善了低温性能;耐老化性能得到改善;耐油性能下降.热失重分析表明,EVM明显改善了NBR胶料的耐高温性能.对硫化体系的研究表明,NBR/EVM并用胶料适合用过氧化物硫化.     

PVC/TPU/NBR三元共混物的制备及性能研究

对PVC／热塑性聚氨酯（TPU）／SR三元共混物的性能进行研究，重点讨论NBR品种、TPU／NBR并用比、PVC聚合度、增塑剂DOP和硫化剂DCP用量对PVC／TPU／NBR三元共混物性能的影响。结果表明。PVC／TPU／NBR-3604三元共混物的物理性能较优；PVC／TPU／NBR-3604三元共混物的拉断伸长率和拉断永久变形均随着PVC聚合度的增大基本呈上升趋势；随着增塑剂DOP用量的增大，共混物的邵尔A型硬度、拉伸强度、撕裂强度和拉断永久变形均基本呈下降趋势，拉断伸长率增大；随着硫化剂DCP用量的增大。共混物的拉伸强度和拉断伸长率变化不大，撕裂强度基本呈逐渐减小的趋势。不同PVC／TPU／SR三元共混物的扫描电子显微镜照片表明，NBR与PVC和TPU的相容性较好。     

Abrasion resistance of thermoplastic polyurethane materials blended with ethylene–propylene–diene monomer rubber

The effect of ethylene–propylene–diene monomer rubber (EPDM) as an additive on the abrasion resistance of a thermoplastic polyurethane (TPU) resin was investigated. The mechanical properties and microstructure of the resultant TPU/EPDM composites were evaluated, and the surface morphology of the composites after abrasion testing was examined. The results showed that the addition of EPDM greatly improved both the mechanical properties and abrasion resistance of the TPU resin. A TPU/EPDM composite with 8 wt % EPDM demonstrated the highest tensile strength, the largest elongation at break, and the best overall performance. The abrasion of this composite was 27 mg, whereas that of the pure resin was 73 mg. With the further addition of EPDM, the abrasion resistance of the resultant composites decreased, whereas the viscosity increased. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

回归分析法研究补强剂对NBR/EVM并用胶性能的影响

采用回归分析法研究了FEF和ZDMA用量对NBR/EVM并用胶性能的影响。结果表明,在试验范围内,随着FEF或ZDMA用量的增加,硫化胶的硬度、拉伸强度、撕裂强度、100%定伸应力、压缩永久变形逐渐增大,而拉断伸长率逐渐减小,耐油性能得到改善;由等高线曲线可以清楚地看出两者用量对性能影响的规律,并可以预测胶料的各项物性与配合剂用量之间的关系。     

Morphologies and mechanical properties of polylactide/thermoplastic polyurethane elastomer blends

To explore a potential method for improving the toughness of a polylactide (PLA), we used a thermoplastic polyurethane (TPU) elastomer with a high strength and toughness and biocompatibility to prepare PLA/TPU blends suitable for a wide range of applications of PLA as general‐purpose plastics. The structure and properties of the PLA/TPU blends were studied in terms of the mechanical and morphological properties. The results indicate that an obvious yield and neck formation was observed for the PLA/TPU blends; this indicated the transition of PLA from brittle fracture to ductile fracture. The elongation at break and notched impact strength for the PLA/20 wt %TPU blend reached 350% and 25 KJ/m², respectively, without an obvious drop in the tensile strength. The blends were partially miscible systems because of the hydrogen bonding between the molecules of PLA and TPU. Spherical particles of TPU dispersed homogeneously in the PLA matrix, and the fracture surface presented much roughness. With increasing TPU content, the blends exhibited increasing tough failure. The J‐integral value of the PLA/TPU blend was much higher than that of the neat PLA; this indicated that the toughened blends had increasing crack initiation resistance and crack propagation resistance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Morphology and mechanical properties of ethylene‐vinyl acetate rubber/polyamide thermoplastic elastomers

High performance thermoplastic elastomers based on ethylene‐vinyl acetate rubber (EVM) and ternary polyamide copolymer (tPA) were prepared through a dynamic vulcanization process in the presence of dicumyl peroxide (DCP). The morphology, crystallization, and mechanical properties of the EVM/tPA blends were studied. A phase transition of EVM/tPA blend was observed at a weight ratio of 60/40. The presence of EVM increased the melting enthalpy at the high temperature of tPA, ascribing to the heterogeneous nucleating effect of EVM. The tensile strength of EVM/tPA (70/30) blends was increased up to 20.5 MPa as the DCP concentration increased to 3.5 phr, whereas the elongation at break of the blends kept decreasing as the DCP concentration increased. The addition of ethylene‐acrylic acid copolymer (EAA) or maleic anhydride‐grafted EVM (EVM‐g‐MAH) to the EVM/tPA blends both induced finer dispersion of the EVM particles in the tPA phase and improvement in the tensile strength and elongation at break of the blends, which were ascribed to the compatibilization of EAA or EVM‐g‐MAH. Finally, a high performance EVM/tPA (70/30) thermoplastic elastomer with Shore A hardness of 75, tensile strength of 24 MPa, elongation at break of 361%, and set at break of 20% was obtained by adding 5 wt % of EVM‐g‐MAH and 3.5 phr DCP. It has great potential in automotive and oil pipeline applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Thermoplastic elastomers-based natural rubber and thermoplastic polyurethane blends

Thermoplastic elastomers based on the blends of thermoplastic polyurethane (TPU) and natural rubber were prepared by a simple blend technique. The influence of the two different types of natural rubber (i.e., unmodified natural rubber (NR) and epoxidized natural rubber (ENR)) on properties of the blends was investigated. The main aim of this study was to improve heat resistance and damping properties, and also to prepare the TPU material with low hardness by blending with various amounts of natural rubber. It was found that the TPU/ENR blends exhibited superior modulus, hardness, shear viscosity, stress relaxation behavior and heat-resistant properties compared to the blends with TPU and unmodified NR. This was attributed to higher chemical interaction between the polar functional groups of ENR and TPU by improving the interfacial adhesion. It was also found that the ENR/TPU blends exhibited finer grain morphology than the blends with unmodified NR. Furthermore, lower tension set, damping factor (Tan ??) and hardness, but higher degradation temperature, were observed in natural rubber/TPU blends compared to pure TPU. This proves the formation of TPU material with high heat resistance, low hardness and better damping properties. However, the blends with higher proportion of natural rubber exhibited lower tensile strength and elongation at break.     

Mechanical,morphological, and thermal properties of (thermoplastic polyurethane)/(chlorinated polyethylene) blends

The preparation and characterization of CPE (chlorinated polyethylene)/TPU (thermoplastic polyurethane) blends with various ratios were investigated. The compatibility, morphology, and rheology, as well as the thermal and physico‐mechanical properties, were studied by differential scanning calorimetry, Fourier‐transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, universal tensile machine analysis, and capillary rheometry. The results showed that CPE is partially miscible with TPU. The introduction of CPE into TPU resulted in a reduction of the viscosity, tensile strength, tear strength, compression set, abrasion resistance, and hardness, whereas the elongation at break was increased. Thermogravimetric analysis showed that the blends underwent two stages of thermal degradation. J. VINYL ADDIT. TECHNOL., 19:192‐197, 2013. © 2013 Society of Plastics Engineers