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     

聚丙烯/三元乙丙橡胶共混体系的研究

研究了三元乙丙橡胶（ＥＰＤＭ）对聚丙烯（ＰＰ）结晶行为的影响以及ＰＰ／ＥＰＤＭ共混物的形态与性能的关系。ＥＰＤＭ对ＰＰ的熔点、结晶温度无明显影响,ＰＰ／ＥＰＤＭ共混物的结晶度随ＥＰＤＭ组份含量的增加而降低,适量的ＥＰＤＭ可使ＰＰ的晶体尺寸减小,晶胞参数与组份比无关。当ＥＰＤＭ用量为３０％～４０％时,共混物的冲击强度迅速提高。     

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。     

聚丙烯／三元乙现橡胶共混体系的研究

研究了三元乙丙橡胶（ＥＰＤＭ）对聚丙烯（ＰＰ）结晶行为的影响以及ＰＰ／ＥＰＤＭ共混物的形态与性能的关系。ＥＰＤＭ对ＰＰ的熔点、结晶温度无明显影响，ＰＰ／ＥＰＤＭ共混物的结晶度随ＥＰＤＭ组份含量的增加而降低，适量的ＥＰＤＭ可使ＰＰ的晶体尺寸减小，晶胞参数与组份比无关。当ＥＰＤＭ用量为３０％￣４０％时，共混物的冲击强度迅速提高。     

PP／PE共混物的拉伸力学性能

应用Ｉｎｓｔｒｏｎ材料试验机，考察了室温下聚丙烯（ＰＰ）与低密度聚乙烯（ＬＤＰＥ）和高密度聚乙烯（ＨＤＰＥ）共混物的拉伸力学性能．结果表明，ＰＰ／ＬＤＰＥ共混物的拉伸强度和弹性模量与组份的关系符合对数混合法则。而ＰＰ／ＨＤＰＥ共混物的力学性能与组份的关系则较为复杂。     

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。     

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。     

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。     

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。     

PP／EVA－15共混物的研究

应用ＳＥＭ和力学性能测试研究了ＰＰ／ＥＶＡ－１５共混物原料配比、工艺条件和微观结构形态对材料性能的影响，对共混物的增韧机理进行了分析。与弹性体（ＥＰＤＭ）改性ＰＰ所作的比较显示，ＥＶＡ－１５对ＰＰ有良好的改性效果，其综合性能优于ＰＰ／ＥＰＤＭ共混物。     

Morphology prediction and the effect of core‐shell structure on the rheological behavior of PP/EPDM/HDPE ternary blends

In this work, the morphologies of polypropylene (PP)/ethylene‐propylene‐diene (EPDM) rubber/high density polyethylene (HDPE) 70/20/10 blends were studied and compared with the predictions of the spreading coefficient and minimum free energy models. The interfacial tension of PP/HDPE, PP/EPDM, and HDPE/EPDM blends were obtained by fitting the experimental dynamic storage modulus data to Palierne's theory. The prediction results showed core‐shell morphology (core of HDPE and shell of EPDM) in PP matrix. The PP/EPDM/HDPE blends were respectively prepared by direct extrusion and lateral injection method. Core‐shell morphology (core of HDPE and shell of EPDM) could be obtained with direct extrusion corresponding to the predicted morphology. The morphology of PP/EPDM/HDPE blends could be effectively controlled by lateral injection method. For PP/EPDM/HDPE blend prepared by lateral injection method, HDPE and EPDM phase were dispersed independently in PP matrix. It was found that the different morphology of PP/EPDM/HDPE blends prepared by two methods showed different rheological behavior. When the core‐shell morphology (core of HDPE and shell of EPDM) appeared, the EPDM shell could confine the deformation of HDPE core significantly, so the interfacial energy contribution of dispersed phase on the storage modulus of blends would be weaken in the low frequency region. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

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。     

Tensile properties and morphology of the dynamically cured EPDM and PP/HDPE ternary blends

The tensile properties and morphology of the polyolefin ternary blends of ethylenepropylene–diene terpolymer (EPDM), polypropylene and high density polyethylene were studied. Blends were prepared in a laboratory internal mixer where EPDM was cured in the presence of PP and HDPE under shear with dicumyl peroxide (DCP). For comparison, blends were also prepared from EPDM which was dynamically cured alone and blended with PP and HDPE later (cure–blend). The effect of DCP concentration, intensity of the shear mixing, and rubber/plastics composition was studied. The tensile strength and modulus increased with increasing DCP concentration in the blends of EPDM-rich compositions but decreased with increasing DCP concentration in blends of PP-rich compositions. In the morphological analysis by scanning electron microscopy (SEM), the small amount of EPDM acted as a compatibilizer to HDPE and PP. It was also revealed that the dynamic curing process could reduce the domain size of the crosslinked EPDM phase. When the EPDM forms the matrix, the phase separation effect becomes dominant between the EPDM matrix and PP or HDPE domain due to the crosslinking in the matrix.     

PP／PE复合基材及其增韧研究

研究了PP/PE共混复合基材的力学性能和形态结构与组成配比的关系.结果表明,PP/HDPE/EPDM和PP/LLDPE共混体系可以制成具有高抗冲击性能的复合基材,且其他力学性能均衡,加工性能良好。弹性体SRS对复合基材的力学性能及形态有较大影响.实验结果表明,LLDPE具有分割、插入、细化PP球晶的作用,并与PP有较好的相容性;EPDM对PP/HDPE共混体系具有良好的增容效果。     

Rheological properties and crystalline structure of the dynamically cured EPDM and PP/HDPE ternary blends

The rheological properties and crystalline structure of the polyolefin ternary blends of EPDM/polypropylene/high density polyethylene were studied. Blends were prepared in a laboratory internal mixer by two different methods. In blend–cure process, blending and curing were performed simultaneously and EPDM was cured by dicumyl peroxide (DCP) in the presence of PP/HDPE under shear. The cure–blend was to cure EPDM alone first under shear (dynamic curing) and then mix the cured EPDM with PP and HDPE. The effect of DCP concentration, intensity of the shear mixing, and the rubber/plastic composition were studied using capillary rheometer and X-ray diffractometer. The PP-rich ternary blends showed the effect of the mechanooxidative degradation of PP by shear and peroxide. The melt viscosity increased with increasing DCP concentration in blends of EPDM-rich compositions. X-ray diffraction studies revealed that the inclusion of 25 wt % of linear EPDM in the PP/HDPE mixture for the PP-rich ternary blends changed the crystal structure of polypropylene component in the ternary blends. However, the dynamic curing did not alter the crystal structure of PP or HDPE in the blends.     

HDPE增韧PP-R/石墨复合材料力学性能的研究

采用高密度聚乙烯(HDPE)为增韧剂、乙烯 丙烯 二烯三元共聚物(EPDM)、乙烯 辛烯共聚物(POE)为相容剂、石墨为功能性助剂制备了以无规共聚聚丙烯(PP R)或嵌段共聚聚丙烯(PP B)为基体的PP R或PP B／HDPE／石墨复合材料。详细研究了HDPE含量、弹性体种类及含量对PP R或PP B／HDPE／石墨复合材料力学性能的影响。结果表明HDPE用量在20%、EPDM含量为5%时,PP R或PP B复合材料力学性能优异;POE可以实现PP R或PP B／HDPE／石墨复合材料力学性能的平衡。     

聚烯烃改性PET的研究

通过PET与PP、HDPE、EPDM挤出共混，注射模塑制得试样。经DTA、SEM和力学性能测试，表征了共混体系的热行为、结构形态和力学性能。结果表明，在PET/PP(EPDM、HDPE)共混体系中，加入少量的PP-g-MI(EPDM-g-MAH、PE-g-MI)，可较好地改善PEt与PP(EPDM、HDPE)之间的相容性，使分散相在PET基体连续相中分散均匀，分散相尺寸减小，增加了两相间界面的粘结力；同时对PET的结晶有较强的促进作用，使其冷结晶温度降低，改善了PET的加工性能；并且能大幅度提高共混物的冲击强度。     

Influence of coalescence and interfacial tension on the morphology of PP/HDPE compatibilized blends

In this paper, the compatibilization of polypropylene (PP)/high-density polyethylene (HDPE) blend was studied through morphological and interfacial tension analysis. Three types of compatibilizers were tested: ethylene-propylene-diene copolymer (EPDM), ethylene-vinylacetate copolymer (EVA) and styrene-ethylene/butylene-styrene triblock copolymer (SEBS). The morphology of the blends was studied by scanning electron microscopy. The interfacial tension between the components of the blends was evaluated using small amplitude oscillatory shear analysis. Emulsion curves relating the average radius of the dispersed phase and the interfacial tension to the compatibilizer concentration added to the blend were obtained. It was shown that EPDM was more efficient as an emulsifier for PP/HDPE blend than EVA or SEBS. The relative role of interfacial tension reduction and coalescence reduction to particle size reduction was also addressed. It was observed that the role of coalescence reduction is small, mainly for PP/HDPE (90/10) blends compatibilized by EPDM, EVA or SEBS. The results indicated that the role of coalescence reduction to particle size reduction is lower for blends for which interfacial tension between its components is low at compatibilizer saturation.     

高密度聚乙烯对改性聚丙烯共混体系力学性能的影响

采用熔融共混法制备聚丙烯(PP)/三元乙丙橡胶(EPDM)/滑石粉(Tacl)/(高密度聚乙烯)HDPE共混材料。研究了HDPE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/EP-DM/Tacl/HDPE共混体系中,HDPE的添加量存在一个饱和值,在这一添加量的前后,韧性和刚性指标曲线有波峰或波谷;不同牌号的2种HDPE,熔融指数高者增韧效果好。