BR/EVA/HIPS TPV的制备和性能研究

采用苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)改善BR/乙烯-乙酸乙烯酯共聚物(EVA)/高抗冲聚苯乙烯(HIPS)共混物的界面相容性,通过动态硫化法制备BR/EVA/HIPS TPV,并对其性能进行研究.结果表明:未加入SBS的BR/EVA/HIPS共混物未表现出橡胶类弹性体特征,而加入适量SBS的共混物表现出典型橡胶类弹性体特征;当SBS用量为8～12份时,BR/EVA/HIPS TPV的综合物理性能较好,拉伸断面平滑,界面相容性良好.     

动态硫化EVA/BR热塑性弹性体的增强研究

采用动态硫化法制备了乙烯-醋酸乙烯共聚物(EVA)/顺丁橡胶(BR)共混型热塑性弹性体(TPE),通过在树脂相中添加HDPE的方式对复合体系进行增强,对其力学性能及断面微观结构进行了研究。结果表明,对于动态硫化EVA/BR共混型TPE,当HDPE填充量在0～30phr的范围内,其动态硫化产物均表现出TPE的特征;随着树脂相中HDPE用量的提高,复合体系的拉伸强度、撕裂强度、邵氏硬度趋于显著提高,断裂伸长率趋于缓慢增加,而扯断永久形变则始终低于25%;FE-SEM的观察表明,动态硫化TPE的拉伸断面上两相界面结合良好;刻蚀样品表面的硫化胶粒子的尺寸在5mm左右且均匀分散。     

充油BR/EVA/SBS/HIPS TPV的结构与性能

采用动态硫化法制备了充油顺丁橡胶(BR)/乙烯-醋酸乙烯共聚物(EVA)/苯乙烯-丁二烯-苯乙烯共聚物(SBS)/高抗冲聚苯乙烯(HIPS)共混型热塑性硫化胶(TPV),研究了在树脂相中填充芳烃油对TPV性能和亚微观结构的影响.结果表明,随着芳烃油用量的提高,TPV的硬度、拉伸永久变形、强度均呈显著下降趋势,而拉断伸长...     

炭黑补强HIPS/SBS/SBR TPV的相态结构和性能研究

采用动态硫化法制备炭黑补强高抗冲聚苯乙烯(HIPS)/苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)/丁苯橡胶(SBR)热塑性硫化胶(TPV),考察炭黑用量对TPV物理性能的影响,通过场发射扫描电子显微镜观察动态硫化过程中橡胶相的形态演变。结果表明:在TPV的分散相中填充炭黑,可使TPV的拉伸强度和撕裂强度提高,炭黑用量(对于SBR胶料)为60份时,TPV拉伸强度和撕裂强度最大;在动态硫化过程中,橡胶相在交联的同时逐渐被撕碎为分散相,动态硫化至8min,橡胶相呈稳定的类球状形貌,粒径为3~6μm,表面为纳米乱片层状结构。     

基于HIPS/废旧SBR胶粉热塑性弹性体的制备及性能

采用熔融共混法,制备高抗冲聚苯乙烯(HIPS)/废旧丁苯胶粉(废旧SBR胶粉)复合体系,通过在基体HIPS中填加芳烃油和苯乙烯-丁二烯-苯乙烯热塑性弹性体(SBS),研究了体系的力学性能及微观相态结构。结果表明,HIPS/废旧SBR胶粉复合体系中填充10份以上的芳烃油,可获得热塑性弹性体(TPE);在HIPS/废旧SBR胶粉/芳烃油体系中加入SBS进行增容,拉断伸长率有较大提高。拉伸断面形貌研究表明,基体中填充芳烃油和SBS,基体无明显塑性变形和撕裂带,断面平坦,体系具有良好的高弹形变回复能力。     

炭黑补强HIPS/SBS/SBR TPV的性能和相态结构研究

采用动态硫化法制备炭黑补强高抗冲聚苯乙烯（HIPS）/苯乙烯-丁二烯-苯乙烯嵌段共聚物（SBS）/丁苯橡胶（SBR）热塑性硫化胶（TPV）,考察炭黑用量对TPV物理性能的影响,通过场发射扫描电子显微镜观察动态硫化过程中橡胶相的形态演变。结果表明：在TPV的分散相中填充炭黑,可使TPV的拉伸强度和撕裂强度提高,炭黑用量（对于SBR胶料）为60份时,TPV拉伸强度和撕裂强度最大;在动态硫化过程中,橡胶相在交联的同时逐渐被撕碎为分散相,动态硫化至8?min,橡胶相呈稳定的类球状形貌,粒径为3～6?μm,表面为纳米乱片层状结构。     

热塑性弹性体在塑胶跑道的冲击吸收性能研究

采用熔融共混法制备了基于高抗冲聚苯乙烯(HIPS)/乙烯-醋酸乙烯酯共聚物(EVA)/废旧橡胶轮胎(WGRT)粉末复合材料的热塑性弹性体(TPE),并以苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)为相容剂。系统研究了不同混合比例的HIPS/EVA/WGRT复合材料机械性能、动态力学性能和低速冲击性能。结果表明,HIPS/EVA/WGRT重量比=40/5/55时,机械性能和动态力学性能达到最好,且在实验范围内,材料冲击吸收性能随着速度增加而逐渐增大。     

动态硫化EVA/SBS复合改性沥青动态力学性能的研究

研究动态硫化乙烯-乙酸乙烯酯共聚物(EVA)/苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)复合改性沥青的动态力学性能,并与基质沥青和SBS改性沥青进行对比.结果表明,与基质沥青和SBS改性沥青相比,EVA/SBS复合改性沥青的复数模量和抗车辙因子明显增大、损耗因子明显减小,说明其高温弹性和高温抗车辙变形能力增强、温敏性显著下降;动态硫化EVA/SBS复合改性沥青的高温弹性、高温抗车辙变形能力和温敏性进一步改善.     

增容高抗冲聚苯乙烯/高乙烯基聚丁二烯橡胶热塑性硫化胶的Mullins效应及其可逆性

采用动态硫化法制备了苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)增容高抗冲聚苯乙烯(HIPS)/高乙烯基聚丁二烯橡胶(HVPBR)热塑性硫化胶(TPV),考察了SBS用量对TPV物理机械性能的影响,表征了TPV的微观形貌,并研究了TPV的Mullins效应及其可逆性。结果表明,SBS可显著改善HIPS/HVPBR体系的相容性,其用量为12份时,TPV的物理机械性能较好;SBS增容TPV的断面平整、结构致密,界面相互作用明显增强;SBS增容TPV在循环单轴拉伸过程中出现明显的Mullins效应,提高应变速率时,TPV的最大应力和内耗呈增大趋势,瞬时残余形变则减小;当拉伸比相同时,TPV经第1次拉伸热处理后,第2次单轴拉伸中TPV的最大应力和内耗均增大,瞬时残余形变则减小。     

炭黑增强高抗冲聚苯乙烯/苯乙烯-丁二烯-苯乙烯/丁苯橡胶热塑性硫化胶的形态演变

采用动态硫化法制备了炭黑增强高抗冲聚苯乙烯(HIPS)/苯乙烯-丁二烯-苯乙烯(SBS)/丁苯橡胶(SBR)热塑性硫化胶(TPV),考察了炭黑填充量对其力学性能的影响,通过场发射扫描电子显微镜(FE-SEM)观察了动态硫化过程中橡胶相的形态演变。结果表明,在TPV的分散相SBR中填充炭黑,可使TPV的力学性能获显著改善;随着动态硫化的进行,橡胶相在交联的同时逐渐被撕碎为分散相,在动态硫化至8 min时橡胶相呈稳定的类球状形貌,其粒径为3~6 μm,且表面呈现出纳米乱片层状结构。     

PP/EVA共混物的动态硫化研究

研究了动态硫化对聚丙烯/乙烯-醋酸乙烯酯共聚物(PP/EVA)共混物的性能和结构的影响。结果表明:动态硫化使PP/EVA共混物的力学性能(尤其是韧性)获得显著提高;通过对交联剂BIPB用量和助硫化剂S用量的合理控制可制得综合性能优异的PP/EVA动态硫化共混物;动态硫化可细化分散于PP基体中的EVA颗粒粒径,改善EVA的分散效果。最终制得的抗冲PP料主要性能均达到或超过国外同类产品水平。     

Rheological,mechanical and morphological properties of thermoplastic vulcanizates based on high impact polystyrene and styrene‐butadiene rubber

Thermoplastic vulcanizates (TPVs) based on high impact polystyrene (HIPS)/styrene‐butadiene rubber (SBR) blends were prepared by dynamic vulcanization technique. The rheological, mechanical and morphological properties of the dynamically vulcanized blends were investigated systematically. As determined by capillary rheometer, the apparent viscosity of the blends decreases as the shear rate increases, indicating obvious pseudoplastic behavior. At low shear rate, the apparent viscosity of these blends is considerably higher than that of neat HIPS and decreases with the increase of HIPS concentration. The increase of HIPS content in the dynamically vulcanized blends contributes to the increase of tensile strength and hardness properties, while elongation at break and tensile set at break reach a maximum at 30 and 50 wt % of the HIPS content, respectively. The etched surfaces of the HIPS/SBR TPVs were investigated using field‐emission scanning electron microscopy, the morphological study reveals continuous HIPS phase and finely dispersed SBR elastomeric phase in the TPVs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

环氧树脂增强天然橡胶/顺丁橡胶并用胶的性能

采用低相对分子质量的液体环氧树脂(EP)与固化剂混合作为增强体的前驱体,比较了其填充天然橡胶(NR)、顺丁橡胶(BR)及两者并用胶的物理机械性能,考察了EP用量对并用胶及炭黑增强并用胶物理机械性能的影响,并通过扫描电子显微镜表征了填充后的NR、BR及并用胶的微观相态结构。结果表明,EP的加入均可提高NR、BR、NR/BR并用胶的物理机械性能,其中并用胶的拉伸强度提高幅度最大;当EP用量约为24份时,NR/BR并用胶的综合性能最佳;EP可以提高炭黑增强NR/BR并用胶的物理机械性能,但提高幅度不大;EP在NR/BR并用胶中呈现规整的圆球形状,直径为1.0～2.5μm。     

Use of crosslinking agent to produce high-performance PLA/EVA blends via reactive processing

Poly (lactic acid) (PLA) is one of the most currently investigated polymers due to its production from renewable sources and biodegradability. Being a brittle polymer, PLA has low toughness, limiting its use for commercial applications. Therefore, the present work aims to produce PLA blends, using the ethylene-vinyl acetate copolymer (EVA), dynamically vulcanized with dicumyl peroxide (DCP) as a crosslinking agent. A 70/30 mixture of PLA/EVA was produced with 0.2, 0.4, 0.6, 0.8, and 1.0 phr DCP. The produced blends were characterized by torque rheometry, melt flow index (MFI), gel content, thermogravimetry (TG), and differential scanning calorimetry (DSC). Tensile properties, impact strength, heat deflection temperature (HDT), and blends morphologies (SEM) were also studied. The presence of increased dynamically vulcanized systems with added DCP was verified through torque rheometry, MFI, and gel content. Substantial increases in the impact strength and elongation at break were observed in PLA/EVA/DCP, providing super-tough materials at 0.6, 0.8, and 1.0 phr of DCP, with impact strengths of 829.5, 860.3, and 890.2 J/m and elongation at break of 138.5, 146.8, and 120.4%, respectively. These results are promising when compared with engineering polymers and blends. This is probably due to in situ compatibilizer PLA-g-EVA, which resulted in a homogeneous morphology as evidenced by SEM images.     

Influence of static and dynamic crosslinking techniques on the transport properties of ethylene propylene diene monomer rubber/poly (ethylene-co-vinyl acetate) blends

The transport characteristics of dynamically and statically cross-linked Ethylene Propylene Diene Monomer/poly (ethylene-co-vinyl acetate) (EPDM/EVA) blends have been examined in the temperature interval of 28–58 °C using benzene, toluene and xylene as probe molecules. The dynamically vulcanized blends exhibited enhanced properties on the sorption and diffusion features compared to the corresponding statically vulcanized blends. In both the cases, as the EVA content increased in the blends, the solvent uptake decreased. The experimental observations have been correlated with the phase morphology of the blends, using scanning electron micrographs. The crystallinity of the blends was studied using X-ray diffraction patterns. Among the three vulcanising systems, viz, sulphur, dicumyl peroxide (DCP), and a mixture consisting of sulphur and peroxide, employed for the matrix, the DCP cross linked system exhibited the lowest solvent uptake. The molar mass between cross links and the diffusion coefficients have been computed to complement the observed sorption behaviour.     

动态硫化制备PA/SAN/NBR合金冲击性能的研究

采用酚醛树脂（PF）、DCP和硫磺等硫化体系对PA／SAN／NBR共混体系进行动态硫化,研究了该共混体系的缺口冲击强度、冲击行为和分散相形态。结果发现,PF比其它硫化体系更有效,可制得超韧的PA／SAN／NBR（50／25／25）合金;SEM照片表明,随着PF用量增加,共混体系中分散相粒子变小,形态变规则,动态硫化体系的相容性变好。