PP/HDPE/EPDM共混物的研究

研究了聚丙烯（ＰＰ）、高密度聚乙烯（ＨＤＰＥ）和ＥＰＤＭ共混制备非交联型ＰＰ／ＨＤＰＥ／ＥＰＤＭ三元共混物。结果表明，当共混比ＰＰ／ＨＤＰＥ／ＥＰＤＭ＝６５／２０／１５，活性碳酸钙为３０份，ＨＤＰＥ品种为ＧＦ７７５０，采用先把ＨＤＰＥ和ＥＰＤＭ预制成混料再与ＰＰ共混的方法，可得到性能良好的ＰＰ／ＨＤＰＥ／ＥＰＤＭ共混物。     

PP／HDPE／EPDM三元共混材料的微观形态结构及增韧机理分析

本文用ＳＥＭ对ＰＰ／ＨＤＰＥ／ＥＰＤＭ三元共混材料的微观形态进行了考察,结果发现,ＥＰＤＭ和ＨＤＰＥ在ＰＰ基体中形成了特定的壳核结构,这一微观结构是共混物强度和韧性兼优的内在原因。在对三元洪混材料的银纹,剪切带考察的基础上,将ＨＤＰＥ和ＥＰＤ协同增韧ＰＰ的增韧机理作了阐述。     

热致性液晶共聚酯／聚丙烯共混物

通过熔融共混制备了不同配比的（ＰＨＢ／ＰＥＴ）／ＰＰ共混物，研究表明，共混物的弯曲弹性模量，弯曲强度及拉伸强度均比ＰＰ有所提高，当液晶含量为１５％，ＰＰ－ｇ－ＭＡＨ为２０％时，（ＰＨＢ／ＰＥＴ）（ＰＰ－ｇ－ＭＡＨ）／ＰＰ三元共混物弯曲弹性模量最大，ＰＰ－ｇ－ＭＡＨ作为两相界面相容剂，改善了两相间的亲合性。ＤＳＣ分析表明，共混物中ＰＰ相的结晶温度有较大幅度的提高，（ＰＨＢ／ＰＥＴ）共聚酯起了ＰＰ结晶     

EPDM/聚烯烃共混型热塑性弹性体的研究

制备ＥＰＤＭ／聚烯烃简单共混型热塑性弹性体。研究了聚合物种类、橡塑比、二元和三元共混对共混物力学性能的影响。结果表明，部分结晶性ＥＰＤＭ共混物的力学性能比无定形ＥＰＤＭ共混物好，部分结晶性ＥＰＤＭ与ＬＤＰＥ（低密度聚乙烯）共混物的拉伸强度大于两者的加和值，而其它二元共混物的拉伸强度均低于两共混单元的加和值；用ＬＤＰＥ部分替代ＰＰ，或用氯磺化聚乙烯（ＣＳＭ）部分替代结晶性ＥＰＤＭ进行三元共混，能改善部分结晶性ＥＰＤＭ／ＰＰ共混物的某些性能。     

PP／EPDM共混体系界面的研究

本文采用马来酸酐对三元乙丙橡胶（ＥＰＤＭ）进行熔融接枝改性，将性后的ＥＰＤＭ与聚丙烯（ＰＰ）共混，对ＰＰ／ＥＰＤＭ和ＰＰ／ＥＰＤＭ－ｇ－ＭＡＨ两种共混体系的界面状况进行了对比。运用Ｈｕｇｇｉｎｓ参数、界面张力参数对界面状况进行了表征；运用扫描电镜（ＳＥＭ）和偏光显微镜对共混物的冲击断口形貌以及结晶情况进行了观察与分析；探讨了界面状况与共混物力学性能以及流变性能间的关系。     

新型增韧剂在聚丙烯改性中的应用研究

本文介绍了新型增韧剂ＴＰＥ用量对ＰＰ／ＴＰＥ共混体主要性能的影响，并对ＰＰ／ＴＰＥ共混比为（９０／１０）及（８０／２０）时，添加ＬＬＤＰＥ三元共混体系性能进行了研究。表明ＴＰＥ的加入使得ＰＰ的韧性增大，且在适量ＬＬＤＰＥ共混条件下，可以保持其拉伸强度降低很小时而冲击强度有显著提高。使三元共混物的综合性能较好。     

PP／HDPE／SBS三元共混物的研究：基体韧性和弹性体分散相对PP三…

研究了固定ＰＰ／ＨＤＰＥ／ＳＢＳ三地共混物配比，采用不同共混工艺条件下的脆－韧转变规律。研究表明：ＰＰ三元共混物的冲击强度与ＳＢＳ分散相粒径有密度关系，当ＳＢＳ分散相粒间距Ｔ等于临界值ＴＣ时、ＰＰ三元共混物将发生脆－韧转变研究还表明基体韧性与ＴＣ有密切关系，当基体韧性增高时，ＴＣ值将增大。     

PP／EPDM／云母共混复合材料的研究

冲击强度和弯曲模量是聚丙烯共混材料中存在的一个矛盾，通过ＰＰ／ＥＰＤＭ／云母三元共混得一以具有高冲击强度和高弯曲模量的硬而韧的复合材料，并将其用于汽车塑料件中。本文研究了ＰＰ／ＥＰＤＭ／云母的共混物配方、共混体系中ＥＰＤＭ和云母含量与冲击强度和弯曲模量间的关系，分析了云母的表面处理及ＰＰ／ＥＰＤＭ／云母材料断面ＳＥＭ照片，提出了该材料的结构形态模型。     

汽车保险杠材料的研究

本文以ＥＰＤＭ为主增韧剂，ＳＢＳ为辅助增韧剂，对ＰＰ进行了三元共混改性，以过氧化苯甲酰作交联剂，使橡胶相内部形成部分交联结构，使材料的力学性能得到改善；通过在材料中填充适量的滑石粉，材料的弯曲强度能够得到保证；并且还讨论了ＰＰ／ＥＰＤＭ／ＳＢＳ的不同配比对共混材料性能的影响，获得的材料性能基本接近汽车保险杠的技术指标。     

国产聚丙烯的增韧改性研究

本文采用共混的方法对ＰＰ进行增韧改性，分别用苯乙烯与丁二烯嵌段共聚物（ＳＢＳ）、三元乙丙橡胶（ＥＰＤＭ）和乙烯与聚烯烃共聚物（ＰＯＥ）作为增韧剂与ＰＰ组成二元及三元共混体系，测试了各共混体系的力学性能，并确定最佳的增韧剂和具有较好的协同效应的共混体系，试验结果表明：ＰＯＥ为ＰＰ的最佳增韧剂，ＰＰ／ＥＰＤＭ／ＳＢＳ三元共混体系具有较好的协同效应。     

PP/HDPE/SBS三元共混物的研究——基体韧性和弹性体分散相对PP三元共混物脆—韧转变的影响

研究了固定PP/HDPE/SBS三元共混物配比,采用不同共混工艺条件下的脆-韧转变规律。研究表明:PP三元共混物的冲击强度与SBS分散相粒径有密切关系。当SBS分散相粒间距T等于临界值T_c时,PP三元共混物将发生脆-韧转变。研究还表明基体韧性与T_c有密切关系,当基体韧性增高时,T_c值将增大。     

PP／HDPE／SBS三元共混物的研究——形态结构与性能

研究了PP/HDPE/SBS三元共混物的性能及形态结构特征。研究结果表明,PP三元共混物的冲击韧性除与SBS的含量密切相关外,还与HDPE的含量有关,HDPE起到了与SBS相似的增韧作用。由于HDPE的掺入,减少了SBS的含量,制成了一种力学性能均衡的超高韧性PP三元共混材料。形态结构的研究表明,共混物中,SBS呈颗粒状分布,另外SBS还与HDPE组成了具有包藏结构的复合粒子。     

Toughening of polypropylene combined with nanosized CaCO3 and styrene–butadiene–styrene

Nanocomposites of nanosized CaCO₃/SBS/PP were prepared by using twin‐screw and single‐screw extruder. By adding nanosized CaCO₃ particles into SBS/PP blend, the notched impact strength, flexural modulus, and tensile strength of the composites can be improved, whereas, by adding microsized CaCO₃ particles into SBS/PP blend, the notched impact strength of the composite is decreased markedly. At nanosized CaCO₃ content of 16 phr (parts per hundred PP resin by weight), the impact strength of nanosized CaCO₃/SBS/PP composite reaches 56.55 KJ/m², which is 1.27 times that of SBS/PP blend. At nanosized CaCO₃ content of 4 phr, the tensile strength of the composites reaches 31.3 MPa, which is 1.23 times that of SBS/PP blend. The maximum and balanced torque of the composites improves significantly by the addition of CaCO₃ nanoparticles. The increased shear force during compounding continuously breaks down SBS particles, resulting in the reduction of the SBS particles size, and improving the dispersion of SBS particles in PP matrix. Thus the toughening effect of SBS on matrix was improved. Simultaneously, the existence of SBS provides the matrix with a good intrinsic toughness, satisfying the condition that nanosized inorganic particle of CaCO₃ efficiently toughens polymer matrix. The synergistic toughening function of nanosized CaCO₃ and SBS on PP matrix was exhibited. POLYM. ENG. SCI. 47:201–206, 2007. © 2007 Society of Plastics Engineers     

SBS和纳米CaCO_3增容PP/SAN体系的研究

研究了苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)单独添加和与纳米CaCO3复配添加对聚丙烯/苯乙烯-丙烯腈共聚物(PP/SAN)共混体系相容性的影响。结果表明:SBS用量为6 phr时,体系的分散性尺寸降低,分布均匀性改善,有一定的增容效果,但当其用量为10 phr时,体系的相容性变差;SBS和纳米CaCO3先在双辊塑炼机上混炼后再复配添加,当纳米CaCO3/SBS质量比为2/1、总添加量为10 phr时,增容效果好于单独添加SBS的体系;改变纳米CaCO3/SBS的配比体,系的拉伸强度和缺口冲击强度变化不大。     

The effect of matrix toughness and dispersed elastomer phase on the brittle-ductile transition in PP/HDPE/SBS blends

In this paper the sbrittle-ductile transition of polypropylene, high density polyethylene, and a styrene-butadiene-styrene triblock copolymer (PP/HDPE/SBS) ternary blends is investigated for fixed compositions and prepared under various conditions. The morphology of the SBS dispersed phase particles and impact strength of the PP ternary blends is closely related to the processing conditions. There is a sharp Brittle-Ductile transition for the ternary blends when interparticle distance T becomes less than the critical interparticle distance T_c. Both the impact strength in general and more specifically, T_c depend upon the toughness of the PP/HDPE composite matrix.     

增韧改性本体PP在中空制品上的应用

本文介绍由小本体ＰＰ、ＨＤＰＥ和ＳＢＳ弹性体组成的三元共混物在中空制品上的应用。通过调整配方，采用二阶共混工艺可制得中抗冲和高抗冲的ＰＰ共混物，其他力学性能下降不大。以配比为７０～６５％ＰＰ、２０～２５％ＨＤＰＥ和１０％ＳＢＳ的共混物用于生产中空制品是可行的，制品的冲击、拉伸等力学性能及外观符合要求，从而扩大了小本体ＰＰ的应用范围。     

PP/HDPE/滑石粉复合材料微孔发泡实验研究

为了改善聚丙烯(PP)的微孔发泡性能,将PP与高密度聚乙烯(HDPE)共混,提高其熔体强度;然后在PP/HDPE共混体系中加入少量滑石粉,研究滑石粉的用量对共混体系熔体强度及微孔发泡过程的影响。研究结果表明,滑石粉的加入使体系的熔体强度提高,发泡样品的泡孔结构变得更均匀。而且,随着滑石粉用量的增加,泡孔尺寸减小,泡孔密度增加。     

Morphology and mechanical properties of biaxially oriented films of polypropylene and HDPE blends

Biaxially oriented films of blends of high-density polyethylene (HDPE) with polypropylene (PP) homopolymer and PP copolymers prepared by twin-screw extrusion and lab-stretcher have been investigated by scanning electron microscopy (SEM), polarized microscopy, differential-scanning calorimeter, and universal testing machine. Three different kinds of PP copolymers were used: (i) ethylene–propylene (EP) random copolymer; (ii) ethylene–propylene (EP) block copolymer; (iii) ethylene–propylene–buttylene (EPB) terpolymer. In the SEM study of the morphology of films of HDPE with various PP blends, phase separation is observed between the PP phase and the HDPE phase for all blends and compositions. In all blends, HDPE serves to reduce the average spherulites size, probably acting as a nucleating agent for PP. The reduction of spherulite size appeared most significantly in the blend of EPB terpolymer and HDPE. A large increase of crystallization temperature was found in the blend of EPB terpolymer and HDPE compared with the unblended EPB terpolymer. For the blend of EPB terpolymer and HDPE, the improvement of tensile strength and modulus is observed with an increase of HDPE content, and this can be considered as a result of the role of HDPE in reducing average spherulite size. © 1994 John Wiley & Sons, Inc.     

Structure and properties of PP/POE/HDPE blends

This work was aimed to counteract the effect of ethylene‐α‐olefin copolymers (POE) by reinforcing the polypropylene (PP)/POE blends with high density polyethylene (HDPE) particles and, thus, achieved a balance between toughness and strength for the PP/POE/HDPE blends. The results showed that addition of HDPE resulted in an increasing wide stress plateau and more ductile fracture behavior. With the increase of HDPE content, the elongation at break of the blends increased rapidly without obvious decrease of yield strength and Young's modulus, and the notched izod impact strength of the blends can reach as high as 63 kJ/m² at 20 wt % HDPE loading. The storage modulus of PP blends increased and the glass transition temperature of each component of the blends shifted close to each other when HDPE was added. The crystallization of HDPE phase led to an increase of the total crystallinity of the blend. With increasing HDPE content, the dispersed POE particle size was obviously decreased, and the interparticle distance was effectively reduced and the blend rearranged into much more and obvious core‐shell structure. The fracture surface also changed from irregular striation to the regularly distant striations, displaying much obvious character of tough fracture. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of ethylene-propylene copolymer with residual PE crystallinity on mechanical properties and morphology of PP/HDPE blends

Morphology and mechanical properties of polypropylene (PP)/high density polyethylene (HDPE) blends modified by ethylene-propylene copolymers (EPC) with residual PE crystallinity were investigated. The EPC showed different interfacial behavior in PP/HDPE blends of different compositions. A 25/75 blend of PP/HDPE (weight ratio) showed improved tensile strength and elongation at break at low EPC content (5 wt %). For the PP/HDPE = 50/50 blend, the presence of the EPC component tended to make the PP dispresed phase structure transform into a cocontinuous one, probably caused by improved viscosity matching of the two components. Both tensile strength and elongation at break were improved at EPC content of 5 wt %. For PP/HDPE 75/25 blends, the much smaller dispersed HDPE phase and significantly improved elongation at break resulted from compatibilization by EPC copolymers. © 1995 John Wiley & Sons, Inc.