动态硫化EPDM／PP热塑性弹性体相态结构及其力学行为

研究动态硫化ＥＰＤＭ／ＰＰ热塑性弹性体相态结构及其力学行为。结果表明：动态硫化ＥＰＤＭ／ＰＰ共混物相态是ＥＰＤＭ橡胶以颗粒状分布在ＰＰ连续相中,这种相态结构一般不随橡塑比的变化而改变,但ＥＰＤＭ橡胶颗粒的形态变化显著。动态硫化ＥＰＤＭ／ＰＰ共混物,在橡塑比小于２５／７５,共混物具有类似橡胶应力－应变特征。     

动态硫化PP／EPDM性能对共混工艺的依赖及其机理研究

本文通过对一步法和母料法两种共混工艺制备的动态硫化ＰＰ／ＥＰＤＭ力学性能、拉伸形变特性,熔体流动行为,交联程度和微观结构等的表征和分析,研究了动态硫化ＰＰ／ＥＰＤＭ性能对共混工艺的依赖及其作用机理。结果显示,在保证有效地提高材料加工流动性的前提下,母料法能有效地抑制动态硫化中ＰＰ的降解,提高ＥＰＤＭ的交联程度,粒度均匀性和分散均匀性,从而强化材料的增韧效果以及其它力学性能,并提高材料性能的均匀性。     

PP／EPDM硫化与非硫化共混物微观形态及流变行为的研究

本文采用二段共混方法，先制得ＰＰ／ＥＰＤＭ硫化与非硫化增韧母料，该两种母料对ＰＰ的改性，其共混物的微观形态及宏观力学性能显示极大的差异。所采用的硫化剂可以使ＰＰ／ＥＰＤＭ共混物中的ＥＰＤＭ发生动态硫化作用，且使ＰＰ接枝于ＥＰＤＭ交联网络上。非硫化体系中ＥＰＤＭ呈根须状分布于ＰＰ球晶之间和内部；而硫化体系中，ＥＰＤＭ主要分布于球晶间，与ＰＰ相呈“海－岛”结构，并与ＰＰ球晶有很好的界面过渡。在ＥＰＤＭ含量相同的情况下，硫化体系比非硫化体系具有更高的耐冲击强度，且ＥＰＤＭ含量愈多时，这种效果愈加明显。流变行为分析表明，ＰＰ／ＥＰＤＭ共混物属于假塑性流体（ｎ＜１），在一定剪切速率下，ＥＰＤＭ含量的增加及ＥＰＤＭ的硫化，都使共混物的表观粘度ηａ增加，挤出膨胀比Ｂ减小，非牛顿指数ｎ减小，非牛顿流体性质更明显。     

EPDM／PP热塑性弹性体的制备及性能研究

以充油三元乙丙橡胶（ＥＰＤＭ）,粉状聚丙烯（ＰＰ）、超细活性滑石粉为基本材料,采用动态硫化法在单螺杆挤出机组上制备ＥＰＤＭ／ＰＰ共混型热塑性弹性体（ＴＰＶ）;用力学性能试验及动态热流变仪方法测定了ＥＰＤＭ／ＰＰ－ＴＰＶ的性能。结果表明,当ＥＰＤＭ充油量为２０％－３０％时,ＥＰＤＭ与ＰＰ熔融共混效果好;ＤＣＰ用量为１．２％－１．５％时,ＥＰＤＭ／ＰＰ共混体系达到完全动态硫化;超细滑石粉最佳添加量为１     

GMA熔融接枝EPDM/NR共混物的动态硫化

研究了甲基丙烯酸缩水甘油酯（ＧＭＡ）熔融接枝ＥＰＤＭ（ＥＰＤＭｇＧＭＡ）与ＮＲ共混物的动态硫化。考察了ＧＭＡ用量、交联剂品种和用量以及动态硫化工艺条件对ＥＰＤＭｇＧＭＡ／ＮＲ动态硫化共混物力学性能的影响。结果表明：与直接静态硫化物相比,动态硫化物的拉伸强度提高了４８２％,热氧老化性能也得到了明显的改善;ＧＭＡ用量为３～５份、二乙烯三胺（ＤＥＴＡ）用量为０３份时,动态硫化共混物的力学性能较好;动态硫化的工艺条件对共混物性能无明显影响。另外,红外光谱测试表明,ＥＰＤＭ确实成功接枝了ＧＭＡ。     

DSC法对动态硫化PP／EPDM中PP—EPDM共交联结构的研究

根据共交联ＰＰ分子与正常ＰＰ分子在结晶与熔融特征及其对外因素响应上的差异,采用ＤＳＣ分析方法,研究了动态硫化ＰＰ／ＥＰＤＭ中ＰＰ－ＥＰＤＭ共交联结构。结果显示在动态硫化ＰＰ－ＥＰＤＭ的熔融ＤＳＣ曲线上的１５０℃曲线上约１５０℃处出现一新的熔融峰,改变结晶速率或ＤＳＣ测试程序,可发现形成这一新峰的化学结构具有强烈的结晶滞后性,而简单共混ＰＰ／ＥＰＤＭ的ＤＳＣ曲线上始终未出现类似新峰。结合化学反应理论     

EPDM/氟橡胶的动态硫化

研究了 Ｅ Ｐ Ｄ Ｍ 硫化体系、硫化剂叔丁基苯酚甲醛树脂（２４０２ 树脂） 用量以及动态硫化时间对 Ｅ Ｐ Ｄ Ｍ／氟橡胶共混物物理性能的影响。结果表明,当２４０２ 树脂用量超过３０ 份时, Ｅ Ｐ Ｄ Ｍ 的硫化程度和动态硫化共混物的力学性能不再变化;动态硫化时间对共混物物理性能的影响不明显。     

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。     

动态硫化PP／HDPE／EPDM三元共混物的流变性能

本文采用不同的硫化剂，不同的硫化时间，对动态硫化的ＰＰ／ＨＤＰＥ／ＥＰＤＭ三元共混物的流变性能进行了研究。结果表明：１共混体系为假塑体，表现出切力变稀现象；２在低剪切应力下，以Ｍ为硫化剂的粘度与纯机械共混体系的粘度有很大差值，此差值随剪切应力的提高迅速减少；３以ＤＣＰ为硫化剂，体系的粘度低于纯机械共混体系的粘度。     

PP/LDPE/EPDM三元共混物流变性能的研究

本文研究了硫化剂体系、炭黑、滑石粉对ＰＰ／ＬＤＰＥ／ＨＤＰＥ三元共混物流变性能的影响。结果表明，过氧化二异丙苯（ＤＣＰ）和硫磺（Ｓ）的配比对共混物熔体中粘度有明显影响。当ＤＣＰ／Ｓ为０８／０３时，共混物的熔体粘度相对较低；当ＤＣＰ／Ｓ为０３／０３时，粘度相对较高。炭黑和滑石粉配合使用比单独使用时更不利于共混物熔体的流动。     

Structure and properties of dynamically cured EPDM/PP blends

The structure and properties of polyolefin blends of ethylene–propylene–diene terpolymer (EPDM) and polypropylene were studied. Blends were prepared in a laboratory internal mixer where EPDM was cured with PP under shear with dicumyl peroxide (DCP) at different shear conditions (blend–cure). Blends were also prepared for comparison from EPDM which were dynamically cured in the absence of PP and blended later (cure–blend). The effect of DCP concentration, intensity of the shear mixing, and rubber/plastic composition were studied. In blend–cure, the melt viscosity increased with increasing DCP concentration in blends of 75% EPDM and 25% PP, but it decreased with increasing DCP concentration in blends of 75% PP and 25% EPDM. In cure–blend, however, the melt viscosity increased with increasing DCP concentration for all compositions. The melt viscosity decreased with increasing intensity of the shear mixing presumably due to the formation of the smaller segregated microdomain of the crosslinked EPDM gels in both blend–cure and cure–blend materials. The crystallization rate was higher in EPDM/PP blends than in PP homopolymer. The crystallization rates for various blending conditions were also compared.     

Properties of dynamically vulcanized EPDM and LLDPE blends

The tensile, rheological, and thermal properties of dynamically vulcanized ethylene–propylene–diene terpolymer (EPDM) and linear low-density polyethylene (LLDPE) blends were reported along with their crystalline structure and morphology. The EPDM/LLDPE blends were prepared in a laboratory internal mixer by simultaneous blending and vulcanization. Vulcanization was performed with dicumyl peroxide. For comparison, linear LLDPE/EPDM blends were also prepared. In comparison to the linear blends, dynamically vulcanized blends showed higher tensile strength and modulus and exhibited improved compatibility. It was found, however, that the crystal structure of LLDPE was not changed by the inclusion of EPDM and the dynamic vulcanization process. © 1996 John Wiley & Sons, Inc.     

阻燃EPDM/PP TPV的研究

研究制备工艺和阻燃剂用量对EPDM／PP阻燃热塑性硫化胶（TPV）性能的影响。结果表明，采用十溴联苯醚（FR-10）／三氧化二锑并用阻燃体系，阻燃剂在动态硫化前加入，EPDM／PPTPV的阻燃性能较好，但物理性能稍差，阻燃剂用量较大时，EPDM／PPTPV的阻燃性能较好，但拉伸强度减小；采用FR—10／三氧化二锑／氢氧化镁并用阻燃体系，氢氧化镁在动态硫化前加入，EPDM／PPTPV的阻燃性能稍好，物理性能和挤出外观质量略差，氢氧化镁用量对EPDM／PPTPV的阻燃性能影响不大。采用FR—1O／三氧化二锑／氢氧化镁并用阻燃体系，氢氧化镁在动态硫化前加入，可制备低硬度阻燃低发烟EPDM／PP TPV。     

EPDM/POE/PP热塑性硫化橡胶材料的制备及性能研究

以三元乙丙橡胶(EPDM)/乙烯-辛烯共聚物(POE)/聚丙烯(PP)为原料,在PP含量固定的情况下,将POE部分取代EPDM,采用动态硫化技术制备出EPDM/POE/PP三元热塑性橡胶材料(TPV),研究不同含量的POE对材料力学性能、流变性能和微观形貌的影响。结果显示,随着POE含量的增加,三元TPV材料的硬度和熔体质量流动速率不断增大;拉伸强度和断裂伸长率呈线性增大,当EPDM/POE/PP比例为45/40/15时,材料力学性能达到最大值。流变性能和微观形貌分析结果表明,EPDM/POE/PP三元TPV材料具有良好的综合性能。     

高韧性和高流动性PP／EPDM共混材料的研制

研究了乙丙橡胶的门尼粘度和结晶性对聚丙烯增韧效果的影响，结果表明，高门尼粘度，部分结晶性橡胶在获得较好韧性的同时不保持较高的刚性，但流动性较差，通过加入ＨＤＰＥ能在复合增韧的同时提高共混物的流动性，添加少量油酸酰胺和硬脂酰胺敢能适当提高共混物的流动性，采用过氧化物降解聚丙烯可以显著提高共混物的流动性，但韧性明显下降，采用可控降解和动态硫化相结合的技术是在得到高韧性，高流动性共混ＰＰ的有效途径。     

Effects of blend composition and dynamic vulcanization on the morphology and dynamic viscoelastic properties of PP/EPDM blends

The morphology and dynamic viscoelastic properties of isotactic polypropylene (PP) blended with oil-free/oil-extended ethylene–propylene–diene (EPDM) rubbers were studied. Unvulcanized and dynamically vulcanized blends with the compositions PP/EPDM = 50/50 and = 30/70 were investigated. The morphology was observed by phase contrasted atomic force microscopy. The dynamic viscoelastic properties were determined with a rheometer of plate–plate configuration. It was shown that the rheological behavior was strongly affected by both the composition and the morphology of the blends. Significant improvement in the flowability of the dynamically vulcanized blends was observed when oil-extended EPDM was used instead of the oil-free version. It was demonstrated that the rheological properties are mostly controlled by the elastomer phase at low frequencies, while in the high-frequency range the influence of PP becomes dominant. The peculiarities in the rheological behavior of the thermoplastic elastomers (uncured blends, TPE) and thermoplastic dynamic vulcanizates (TPV, dynamically cured blends) containing oil-extended EPDMs were traced to a limited compatibility between the PP and EPDM components in the melt. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

增强三元乙丙橡胶粘合性能的研究

研究烷基酚醛树脂用量、硫化剂DCP/TAIC用量比、增塑剂用量以及硫化工艺对三元乙丙橡胶(EPDM)粘合性能的影响。结果表明:烷基酚醛树脂可提高EPDM与聚酯线绳的粘合性能;随硫化剂DCP/TAIC用量比增大,EPDM与聚酯线绳的粘合性能先提高后保持不变,用量比为9/1时综合性能最佳;EPDM与聚酯线绳的粘合性能随增塑剂2280用量增大几乎呈线性下降趋势;在充分硫化情况下,低温长时间硫化和高温快速硫化工艺对粘合性能影响不大,为提高生产效率,EPDM汽车多楔带可采用高温快速硫化工艺。     

用顺酐化EPDM增容的EPDM改性聚甲醛

以顺酐化三元乙丙橡胶（ＭＥＰＤＭ）为增容剂，研究了ＥＰＤＭ对聚甲醛（ＰＯＭ）的共混增韧生。结果表明，ＭＥＰＤＭ能明显改善ＰＯＭ与ＥＰＤＭ的相容性，使共混物分散相尺寸明显减少，分布更均匀，熔点和结晶度降低，缺口冲击强度提高。当ＰＯＭ／ＥＰＤＭ／ＭＥＰＤＭ（质量比）为８５／９／６时，共混物的缺口冲强度为１０．２ｋＪ／ｍ＾２。     

高抗冲高刚性EPDM改性聚丙烯的研究

加入超细改性无机刚性粒子提高三元乙丙橡胶(EPDM)的硬度，再与聚丙烯(PP)进行共混。研究了超细改性无机刚性粒子用量对EPDM硬度及流动性的影响，比较了PP与不同硬度EPDM的共混物在力学性能上的差异。结果表明：随着EPDM硬度的增加，共混物不仅韧性提高，弯曲模量也大幅度上升。选择合适的硬度，可制得高抗冲高刚性的EPDM改性PP共混材料。     

Mechanical properties,morphological structure,and thermal behavior of dynamically photocrosslinked PP/EPDM blends

A dynamically photocrosslinked polypropylene (PP)/ethylene–propylene–diene (EPDM) rubber thermoplastic elastomer was prepared by simultaneously exposing the elastomer to UV light while melt‐mixing in the presence of a photoinitiator as well as a crosslinking agent. The effects of dynamic photocrosslinking and blend composition on the mechanical properties, morphological structure, and thermal behavior of PP/EPDM blends were investigated. The results showed that after photocrosslinking, tensile strength, modulus of elasticity, and elongation at break were improved greatly. Moreover, the notched Izod impact strength was obviously enhanced compared with corresponding uncrosslinked blend. Scanning electron microscopy (SEM) morphological analysis showed that for uncrosslinked PP/EPDM blends, the cavitation of EPDM particles was the main toughening mechanism; whereas for dynamically photocrosslinked blends, shear yielding of matrix became the main energy absorption mechanism. The DSC curves showed that for each dynamically photocrosslinked PP/EPDM blend, there was a new smaller melting peak at about 152°C together with a main melting peak at about 166°C. Dynamic mechanical thermal analysis (DMTA) indicated that the compatibility between EPDM and PP was improved by dynamic photocrosslinking. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3371–3380, 2004