PP/EPDM共混体系增韧技术研究进展

从乙烯/丙烯/二烯烃共聚物(EPDM)增韧、β–PP晶增韧以及刚性粒子增韧等方面对PP/EPDM共混体系的增韧技术进行综述,展望了PP增韧改性研究的发展趋势。     

PP/EPDM/纳米弹性体粒子三元共混体系的脆韧转变

研究了PP／EPDM／纳米弹性体粒子(ENP)三元共混体系的脆韧转变行为。结果表明，与PP／EPDM二元共混物相比，三元共混物的脆韧转变可以在EPDM质量分数较低的情况下发生；在橡胶总质量分数相同的情况下，三元共混物有更高的冲击强度，拉伸强度有一定提高。从脆断样条的扫描电镜照片观察到，在相同EPDM质量分数下，PP／EPDM／ENP三元共混物中的EPDM粒子明显细化，分布均一，粒子间距减小，这是脆韧转变提前的原因。     

1999年中国高分子材料老化与应用文摘

EPDM/PP共混物老化性能的研究/赵永仙(青岛化工学院)/塑料工业.1999,27(4),30～31转38.研究了三元乙丙橡胶(EPDM)改性聚丙烯(PP)共混物的性能,探讨了不同含量的EPDM对共混物力学性能、热性能、流变性能的影响,还探讨了不同品种、不同含量的抗氧剂对共混物耐老化性能的影响.经EPDM改性的PP拉伸强度降低、冲击强度和断裂伸长率提高耐热,性、熔点随EPDM含量增加而降低,熔体粘度增大,假塑性增强,添加抗氧剂大大提高了共混物的耐老化能力、主辅抗氧剂并用效果更好.获得了能在高温下长期工作的改性PP共混物.     

PP的共混改性研究进展

本文综述了近年来有关PP共混改性的各种方法与技术进展，总结了不同物质如弹性体、塑料、无机刚性粒子等增韧PP的机理，并介绍了多种相关共混改性产品的应用状况。     

微-纳米无机粒子改性聚丙烯材料的最新进展

综述了近年来微-纳米无机刚性粒子填充改性聚丙烯(PP)材料的最新进展,介绍了微米级、纳米级和微-纳米组合无机刚性粒子的添加对PP复合材料性能的影响。无机刚性粒子越细,越有利于PP材料的增强增韧;无机刚性粒子的表面改性处理对复合材料的微观结构和性能有重要影响。微米无机刚性粒子可提高PP材料的抗冲击强度与刚性,但强度会有所降低;均匀分散的无机纳米粒子同时起到增强增韧的双重作用;具有粒径级的组合粒子的填充改性优于单一无机粒子。     

三元乙丙橡胶共混改性聚丙烯

分别用茂金属催化聚合所得的三元乙丙橡胶(mEPDM)和传统Ziegler-Natta催化剂聚合所得的三元乙丙橡胶(EPDM)对PP进行共混改性。考察了增韧剂质量分数对共混物冲击强度、拉伸强度和热变形温度等力学性能的影响,以及共混物结构形态和结晶行为。结果表明,与PP／EPDM共混物相比,PP／mEPDM共混物的脆韧转变增韧剂临界质量分数小,扯断伸长率高。PP／mEPDM共混物的脆韧转变区间远小于PP／EPDM共混物。随增韧剂质量分数的增加,PP／mEPDM和PP／EPDM共混物的拉伸强度、弹性模量和维卡软化点均单调下降,但后者的下降幅度更大。电镜分析和结晶行为研究表明,PP与mEPDM的相容性优于PP与EPDM的。     

EPDM对改性PP共混体系力学性能的影响

本文采用熔融共混法制备聚丙烯（PP）／三元乙丙橡胶（EPDM）／滑石粉共混材料。研究了EPDM对改性PP共混体系力学性能的影响及其原因．结果表明，在PP／EPDM／Talc共混体系中，EPDM含量达到约15％之后，材料的韧性指标开始飞速提高，刚性强度都开始下降。通过试验的正交偏光显微镜照片对力学性能变化趋势进行了探索。     

高模量弹性体对PP结晶行为及力学性能的影响

应用DSC和力学性能测试研究了PP/OTE、PP/EPDM共混物的结晶行为和它们的增韧作用。结果表明 ,烯烃类热塑性弹性体 (以下简称OTE)对PP的结晶性能无明显影响 ,EPDM对PP成核速率有促进作用。PP/OTE在赋予PP较好低温韧性的同时 ,使共混物的刚性得以适度兼顾 ,且易于加工。PP/OTE共混体系的综合性能优于PP/EPDM共混物     

PBt-TPE、EPDM、POE等弹性体改性PP性能的研究

研究了自制的聚1-丁烯热塑性弹性体(PBt-TPE)及市售的三元乙丙橡胶(EPDM)和乙烯-辛烯共聚物(POE)3种弹性体改性聚丙烯(PP)共混物的性能,比较了3种改性体(PBr-TPE、EPDM、POE)对PP共混物力学性能和热性能的影响,结果表明3种弹性体对PP具有相似的改性效果,共混物的断裂伸长率和冲击强度等韧性指标均有明显改善;PBt-TPE在某些方面可替代EPDM作为PP的改性剂,其工业化产品将具有明显的价格优势.     

不同交联剂对动态硫化PP/EPDM共混物的影响

研究了不同的交联剂对过氧化物硫化的PP/EPDM共混物力学性能的影响,并通过扫描电镜观察其相形态。结果表明:交联剂二-三甲醇基丙烷-四丙烯酸酯(DTMPTA)、四甘醇基-二丙烯酸酯(TTEGDA)都能使EPDM发生交联。随着交联剂中官能团的增加,PP/EPDM共混物的熔体流动速率(MFR)逐渐降低,冲击强度增加,屈服应力增大,其中以TTEGDA交联剂制备共混物的力学性能最佳。扫描电镜(SEM)发现动态硫化PP/EPDM中EPDM相的平均粒子尺寸要小于物理共混物中EPDM相的平均粒子尺寸。     

EPDM/POE/PP共混制备热塑性弹性体的性能研究

采用动态硫化的方法制备三元乙丙橡胶（EPDM）/聚烯烃弹性体（POE）/聚丙烯（PP）热塑性弹性体,讨论了EPDM、硫化剂、炭黑的用量和填料种类对热塑性弹性体性能的影响。结果表明：随着EPDM用量的增加,EPDM/POE/PP热塑性弹性体的拉伸强度、定伸应力和硬度都呈减小趋势,而拉断永久变形呈上升趋势;随着SP-1055用量的增加,其压缩永久变形显著降低;随着炭黑用量的增加,弹性体的拉伸强度、定伸应力和硬度先下降后增加,而拉断伸长率、拉断永久变形和压缩永久变形先增大后降低;在不同填料种类中用N85作为填料时,弹性体的综合性能最好,压缩永久变形最小。     

动态硫化EPDM/PP共混物力学性能的研究

考察了硫黄用量和聚合物共混比对动态硫化ＥＰＤＭ／ＰＰ热塑性弹性体性能的影响。结果表明,随着硫黄用量增大,ＥＰＤＭ／Ｐ共混物的拉伸强度、１００％定伸应力和扯断伸长率先增大后减小、硬度有所增大,随着ＰＰ用量的增大,ＥＰＤＭ／ＰＰ共混物的拉伸强度、１００％定伸应力和硬度均有所增大,扯断伸长率也先大后减小。ＰＰ用量的变化对这些性能的影响更显。     

Mechanical properties of wood-fiber/toughened isotactic polypropylene composites

This study investigates the mechanical properties of wood-fiber/toughened PP composite modified by physical blending with an EPDM rubber to improve impact toughness. Wood-fiber thermoplastic composites were prepared with a modified PP matrix resin, employing high shear thermokinetic compounding aided with maleated PP for the fiber dispersion. The addition of EPDM improved the impact toughness, while it reduced stiffness and strength properties. To compensate the non-plane strain fracture toughness, the specimen strength ratio (R_sb) was adopted as a comparative measure of fracture toughness. The strength ratio increased with the addition of EPDM, while it decreased with increasing wood-fiber concentration. The work of fracture increased with EPDM level except at large wood-fiber concentration. The effectiveness of the impact modification was assessed with the balance between tensile modulus and unnotched impact energy as a function of wood-fiber concentration. EPDM rubber modification was moderately effective for wood-fiber PP composites. The examination of fracture surfaces showed twisted fibers, fiber breakage, and fiber pull-out from the matrix resin.     

EPDM／PP／HDPE动态硫化热塑性弹性体力学性能的研究

研究了EPDM／PP／HDPE动态硫化热塑性弹性体中三元乙丙橡胶（EPDM）和高密度聚乙烯（HDPE）对动态硫化热塑性弹性体的力学性能影响。结果表明：EPDM可以改变聚丙烯（PP）和HDPE结晶度,有利于应力的平均分布,使体系的硬度降低。HDPE作为第三相,可以改善PP与EPDM之间的相界面结构,增加体系的相容性。在EPDM／PP橡塑比较低时加入HDPE对体系力学性能影响更明显。     

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。     

The influence of matrix viscosity and composition on the morphology,rheology, and mechanical properties of thermoplastic elastomer nanocomposites based on EPDM/PP

The morphological and rheological properties of thermoplastic elastomer nanocomposites (TPE nanocomposites) were studied using different viscosities of polypropylene (PP) and ethylene‐propylene‐diene monomer (EPDM) rubber content (20, 40, 60 wt%). The components, namely EPDM, PP, Cloisite 15A, and maleic anhydride‐modified PP as compatibilizer, were compounded by a one‐step melt mixing process in a laboratory internal mixer. The structure of the nanocomposites was characterized with X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and rheometry in small amplitude oscillatory shear. The distribution state of the clay between the two phases (PP and EPDM) was found to be dependent on the viscosity ratio of PP to EPDM. In the nanocomposites prepared based on low viscosity PP (LVP) and EPDM, the clay was mostly dispersed into the PP phase and the size of the dispersed rubber particles decreased in comparison with unfilled but otherwise similar blends. However, the dispersed elastomer droplet size in the high viscosity PP (HVP) blends containing 40 and 60% EPDM increased with the introduction of the clay. For TPE nanocomposites, the dependence of the storage modulus (G′) on angular frequency (ω) followed a clear nonterminal behavior. The increase in the storage modulus and the decrease in the terminal zone slope of the elastic modulus curve were found to be larger in the LVP nanocomposite in comparison with the HVP sample. The yield stress of nanoclay‐filled blends prepared with LVP increased more than that of HVP samples. The tensile modulus improved for all nanocomposites but a higher percentage of increase was observed in the case of LVP samples. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

EPDM/PP共混型热塑性硫化胶的增容研究

研究了酚醛树脂接枝改性聚丙烯(PP-g-MP)和马来酸酐接枝改性茂金属乙烯-辛烯共聚物(EOC-g-MAH)对动态硫化EPDM/PP共混型热塑性硫化橡胶(TPV)的增容作用,探讨了增容剂对TPV的物理机械性能、形态结构和流变性能的影响。结果表明,PP-g-MP能够提高EPDM/PPTPV的100%定伸应力和拉伸强度,但扯断伸长率下降;适量的EOC-g-MAH能够提高EPDM/PPTPV的拉伸强度和扯断伸长率,但100%定伸应力下降。接枝率越高,TPV的拉伸强度和扯断伸长率也越高。通过相差显微镜分析表明,加入增容剂有助于橡胶粒子的更精细、更均匀地分散,EOC-g-MAH的增容作用更佳。加入EOC-g-MAH后TPV的切敏性更显著。     

Comparative study of silica-, nanoclay- and carbon black-filled EPDM rubbers

Silica-, nanoclay-, and carbon black (CB)-filled ethylene–propylene–diene terpolymer (EPDM) mixtures were prepared and subsequently vulcanized. Rheological properties and cure characteristics of the mixtures and mechanical properties of vulcanizates were measured. Rheological property measurements indicated the storage modulus, loss modulus, and complex dynamic viscosity of silica-filled EPDM mixtures were much higher than those of CB-filled EPDM mixtures while tan δ values were lower. The optimum cure time of silica- and nanoclay-filled EPDM mixtures increased with filler loading, whereas the values for CB-filled mixtures slightly decreased with loading. The hardness, modulus, elongation at break, and tensile strength of all the vulcanizates increased with increasing filler loading. The elongation at break of CB-filled EPDM vulcanizates increased insignificantly with CB loading. Among the three fillers, the increase of the tensile strength and elongation at break was most significant for silica-filled EPDM vulcanizates. Remarkably, for 30 phr silica-filled EPDM vulcanizates, a tensile strength and elongation at break of 23.5 MPa and 1045% was achieved, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

改性纳米氮化硅/EPDM复合材料的制备与性能研究

分别采用液体聚丁二烯接枝甲基丙烯酸缩水甘油酯(LMPB-g-GMA)和无规聚丙烯接枝马来酸酐(APP-gMAH)对纳米氮化硅进行改性,制备改性纳米氮化硅/EPDM复合材料,并对复合材料的性能进行研究.结果表明:改性纳米氮化硅对EPDM具有良好的补强作用;随着改性纳米氮化硅用量的增大,复合材料邵尔A型硬度变化不大,定伸应力、拉伸强度和撕裂强度总体呈先增大后减小的趋势; LMPB-g-GMA改性纳米氮化硅/EPDM复合材料的拉伸性能和压缩永久变形优于APP-g-MAH改性纳米氮化硅/EPDM复合材料,但耐热空气老化性能略差.     

Effect of talc on the properties of polypropylene/ethylene/propylene/diene terpolymer blends

In the present study, the effect of talc content on the mechanical, thermal, and microstructural properties of the isotactic polypropylene (i‐PP) and elastomeric ethylene/propylene/diene terpolymer (EPDM) blends were investigated. In the experimental study, five different talc concentrations, 3, 6, 9, 12, and 15 wt %, were added to i‐PP/EPDM (88/12) blends to produce ternary composites. The mechanical properties such as yield and tensile strengths, elongation at break, elasticity modulus, izod impact strength for notch tip radius of 1 mm, and hardness with and without heat treatments and thermal properties, such as melt flow index (MFI), of the ternary composites have been investigated. The annealing heat treatment was carried out at 100°C for holding time of 75 h. From the tensile test results, an increased trend for the yield and tensile strengths and elasticity modulus was seen for lower talc contents, while elongation at break showed a sharp decrease with the addition of talc. In the case of MFI, talc addition decreased the MFI of i‐PP/EPDM blends. It was concluded that, taking into consideration, mechanical properties and annealing heat treatment, heat treatment has much more effect on higher yield and tensile strengths, elongation at break, elasticity modulus, impact strength, and hardness. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3033–3039, 2006