动态固化聚丙烯／马来酸酐接枝聚丙烯／滑石粉／环氧树脂复合材料研究

将动态硫化技术应用于热塑性树脂／填料／热固性树脂复合体系，制备了动态固化聚丙烯(PP)／马来酸酐接枝PP(PP-g-MAH)/滑石粉(Talc)／环氧树脂(EP)复合材料。研究了动态固化PP／PP-g-MAH/Talc／EP复合材料的界面作用、形态结构、力学性能以及热稳定性。实验结果表明：PP／PP-g—MAH的加入，可明显增加PP/Talc复合材料的界面作用。在动态固化PP／PP-g-MAH/Talc／EP复合材料中，PP和Talc两相界面更加模糊，动态固化EP进一步增加了PP和Talc间的界面作用。当EP的用量超过5份时，部分EP呈颗粒状分布在PP基体中。与PP／PP-g-MAH/Talc／EP和PP／PP-MAH-Talc／EP复合材料相比，动态固化PP／PP-g-MAH/Talc／EP复合材料的冲击强度、拉伸强度和弯曲模量均有明显提高。当EP用量超过5份时，复合材料的冲击强度和断裂伸长率明显降低，但拉伸强度和弯曲模量继续增加。热分析表明动态固化PP／PP-g-MAH/Talc／EP复合材料具有较高的热稳定性。     

纳米碳酸钙和三元乙丙橡胶接枝马来酸酐协同增韧聚丙烯

纳米碳酸钙和三元乙丙橡胶接枝马来酸酐对聚丙烯具有显著的协同增韧作用，可能是因为纳米碳酸钙和三元乙丙橡胶接枝马来酸酐之间发生物理化学作用，形成一种新的核壳结构（硬核软壳），与一般的核壳增韧剂（硬壳软核）完全不同。     

动态硫化增韧聚丙烯／三元乙丙橡胶共混物的研究

研究了动态硫化和简单共混增韧聚丙烯（PP）／三元乙丙橡胶（EPDM）共混物的力学性能、形态结构、流动性能和脆韧转变。结果表明：动态硫化的增韧效率要比简单共混的增韧效率高；随着EPDM用量的增加，共混物的力学性能均随之发生变化，流动性明显降低；简单共混物的橡胶颗粒尺寸随EPDM含量的增加呈增大趋势，而动态硫化可以降低橡胶颗粒的尺寸；动态硫化物的临界基体层厚度大约为0.3μm，简单共混物的临界基体层厚度大约为0．2μm，并且动态硫化和简单共混物均在各自的临界基体层厚度处发生脆韧转变，验证了wu氏增韧理论。     

马来酸酐接枝EPDM改性聚丙烯的制备及性能研究

采用聚丙烯(PP)为母体材料,三元乙丙橡胶(EPDM)和三元乙丙橡胶接枝马来酸酐(EDPM-g-MAH)作为增韧剂改性PP,制备共混材料。研究结果表明:与纯EPDM改性PP相比较,EPDM-g-MAH改性PP获得的共混材料的性能更佳,具有良好的弯曲模量及冲击强度,维卡软化点显著降低,对于材料的耐热性的提高具有一定作用。同时在PP/EPDM-g-MAH共混材料的冲击断裂表面发现较为粗糙的结构,表明EPDM-g-MAH作为增韧剂填充PP,对于提高PP的韧性,提高材料的抗冲击性能具有明显的作用。     

马来酸酐熔融接枝聚丙烯及其共混物

用双螺杆挤出机通过反应性挤出制备了马来酸酐熔融接枝的聚丙烯(PP),对均聚PP、嵌段共聚PP、PP/三元乙丙橡胶和PP/聚烯烃热塑性弹性体复合体系与马来酸酐的熔融接枝及其工艺条件进行了探讨.结果表明,采用嵌段共聚PP接枝马来酸酐,在螺杆温度190～210 ℃、过氧化二异丙苯质量分数0.1%、马来酸酐质量分数1.5%及苯乙烯质量分数1.8%时,可获得接枝率3.8%的PP接枝聚合物.用该接枝聚合物与PP、高密度聚乙烯及聚烯烃热塑性弹性体熔融共混制备的黏合性涂覆树脂能够满足化工容器防腐专用料的性能要求.     

动态硫化聚丙烯／三元乙丙橡胶共混材料

采用动态硫化技术研制了聚丙烯/三元乙丙橡胶共混材料(PP/EPDM)。考察了EPDM含量对共混材料力学性能、热性能的影响,研究了共混材料的流变性能,以及注射成型工艺条件与成型收缩率之间的关系。     

熔融法马来酸酐接枝改性三元乙丙橡胶及其氯化聚乙烯共混物

采用熔融接枝法制备了马来酸酐（MAH）接枝三元乙丙橡胶（EPDM）（EPDM-g-MAH）,并与橡胶型氯化聚乙烯（CM）共混,考察了EPDM-g-MAH接枝率的影响因素,研究了EPDM-g-MAH及其共混物的性能、微观形态。结果表明,当MAH、过氧化苯甲酰的最佳用量分别为8.0、0.6份时,最大接枝率约为2.5%;相比未接枝的EPDM,EPDM-g-MAH的正硫化时间稍长,并具有较长的硫化平坦期,拉伸性能得到改善;随着CM用量的增加,EPDM-g-MAH/CM共混物的拉伸强度略有降低,但高于EPDM/CM共混物,扯断伸长率变化不大,邵尔A硬度先升高后降低;EPDM-g-MAH/CM（质量比80/20）共混物中两相界面模糊,表明EPDM-g-MAH与CM相容性变好。     

马来酸酐在乙丙橡胶上的接枝共聚

马来酸酐在乙丙橡胶上的接枝共聚,用过氧化苯甲酰为引发剂的效果优于偶氮二异丁腈。研究了温度、马来酸酐用量和引发剂用量等对接枝率的影响。用红外光谱和薄层色谱证明了接枝物的存在。用接触角技术测定了接枝物的表面性能。     

聚丙烯/马来酸酐接枝聚丙烯/环氧树脂/玻璃纤维复合材料的制备及其性能研究

通过双螺杆挤出机制备了聚丙烯/马来酸酐接枝聚丙烯/环氧树脂/玻璃纤维（PP/PP-g-MAH/EP/GF）复合材料,并研究了PP-g-MAH含量、EP含量及固化剂对复合材料力学性能的影响。结果表明,PP-g-MAH含量为10份,含有固化剂EP的含量为3份时,复合材料的综合力学性能最佳;与不加EP的复合材料相比,其拉伸强度、弯曲强度、冲击强度分别提高了41 %、47 %、86 %。扫描电子显微镜分析表明,EP的加入明显改善了GF和PP基体的黏结强度。     

马来酸酐接枝聚丙烯的进展

马来酸酐接枝聚丙烯是拓宽聚丙烯应用领域的重要手段之一,本文综述了马来酸酐接枝聚丙烯的接枝方法和原理,接枝物的性能以及接枝物在聚丙烯合金和共混物、复合材料、粘合剂和涂料领域的广泛应用。     

Dynamically cured PP/MAH-g-SEBS/epoxy blends

Abstract

A new method concerning the simultaneous reinforcing and toughening of polypropylene (PP) is reported. Dynamic cure of the epoxy resin with 2-ethylene-4-methane-imidazole was successfully applied in the PP/maleic anhydride grafted styrene–ethylene–butylene–styrene (MAH-g-SEBS) triblock co-polymer, and the obtained blends were named as dynamically cured PP/MAH-g-SEBS/epoxy blends. The stiffness and toughness of the blends are in a good balance, and the smaller size of the epoxy particle in the PP/MAH-g-SEBS/epoxy blends shows that MAH-g-SEBS was also used as a compatibiliser. The structure of the dynamically cured PP/MAH-g-SEBS/epoxy blends is the embedding of the epoxy particles by MAH-g-SEBS. The cured epoxy particles as organic filler increase the stiffness of the PP/MAH-g-SEBS blends, and the improvement in the toughness is attributed to the embedded structure. The tensile strength and flexural modulus of the blends increase with increasing epoxy resin content, and the impact strength reaches a maximum of 342 J m^?1 at the epoxy resin content of 10wt-%. Differential scanning calorimetry analysis shows that the epoxy particles in the dynamically cured PP/MAH-g-SEBS/epoxy blends could have contained embedded MAH-g-SEBS, decreasing the nucleating effect of the epoxy resin. Wide angle X-ray diffraction analysis shows that the dynamical cure and compatibilisation do not disturb the crystalline structure of PP in the blends.     

EPDM与PP的动态硫化橡胶

对EPDM与PP的几种混炼方式进行了综述,讨论了动态硫化橡胶的流变学和形态学性能。     

Dynamically cured polypropylene/epoxy blends

The dynamic vulcanization process, usually used for the preparation of thermoplastic elastomers, was used to prepare polypropylene (PP)/epoxy blends. The blends had crosslinked epoxy resin particles finely dispersed in the PP matrix, and they were called dynamically cured PP/epoxy blends. Maleic anhydride grafted polypropylene (MAH‐g‐PP) was used as a compatibilizer. The effects of the reactive compatibilization and dynamic cure were studied with rheometry, capillary rheometry, and scanning electron microscopy (SEM). The crystallization behavior and mechanical properties of PP/epoxy, PP/MAH‐g‐PP/epoxy, and dynamically cured PP/epoxy blends were also investigated. The increase in the torque at equilibrium for the PP/MAH‐g‐PP/epoxy blends indicated the reaction between maleic anhydride groups of MAH‐g‐PP and the epoxy resin. The torque at equilibrium of the dynamically cured PP/epoxy blends increased with increasing epoxy resin content. Capillary rheological measurements also showed that the addition of MAH‐g‐PP or an increasing epoxy resin content increased the viscosity of PP/epoxy blends. SEM micrographs indicated that the PP/epoxy blends compatibilized with PP/MAH‐g‐PP had finer domains and more obscure boundaries than the PP/epoxy blends. A shift of the crystallization peak to a higher temperature for all the PP/epoxy blends indicated that uncured and cured epoxy resin particles in the blends could act as effective nucleating agents. The spherulites of pure PP were larger than those of PP in the PP/epoxy, PP/MAH‐g‐PP/epoxy, and dynamically cured PP/epoxy blends, as measured by polarized optical microscopy. The dynamically cured PP/epoxy blends had better mechanical properties than the PP/epoxy and PP/MAH‐g‐PP/epoxy blends. With increasing epoxy resin content, the flexural modulus of all the blends increased significantly, and the impact strength and tensile strength increased slightly, whereas the elongation at break decreased dramatically. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1437–1448, 2004     

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.     

动态硫化EPDM/PP共混型热塑性弹性体的研究

研究了ＥＰＤＭ／ＰＰ共混比、不同牌号ＰＰ、硫化体系、混炼方式和软化剂用量对动态硫化ＥＰＤＭ／ＰＰ共混物性能的影响。研究结果表明,当ＥＰＤＭ／ＰＰ共混比为６５／３５,经一步混炼法制出的共混物的拉伸强度大于８ＭＰａ,扯断伸长率达４００％,撕裂强度为４０ｋＮ·ｍ－１,屈挠寿命大于１０万次,邵尔Ａ型硬度为７０～８０度。软化剂用量在３０份以内为宜。     

Dynamically vulcanized PP/EPDM blends by multifunctional peroxides: Characterization with various analytical techniques

The characterization of peroxide‐cured PP/EPDM TPVs using various spectroscopic techniques is difficult. These techniques are most suited for analysis of solutions, while the PP‐phase does not dissolve in common organic solvents at room temperature. To obtain more insight into the chemistry and reactivity involved between the multifunctional peroxides and EPDM rubber, several characterization techniques were employed. In the present investigation, FTIR, GC‐(FID + MS), HP‐SEC, and element analysis were used to characterize the multifunctional peroxides TBIB and DTBT, before and after the dynamic curing of the EPDM phase. The decomposition products obtained from these multifunctional peroxides are most likely grafted onto the EPDM‐rubber, thereby reducing their volatility and avoiding the common unpleasant smell. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1393–1403, 2005     

Dynamically vulcanized PP/EPDM blends: Influence of curing agents on the morphology evolution

Thermoplastic vulcanizates (TPE‐Vs) are a special class of thermoplastic elastomers (TPEs), where the rubber phase is dynamically crosslinked in the presence of a thermoplastic matrix. The goal of this work is to compare the behavior of two curing agents systems, conventional peroxide named Peroximon and bismaleimide/dicumyl peroxide, in TPE‐Vs based on PP/EPDM 35/65 w/w. It was also investigated the TPE‐Vs morphological evolution and samples was collected at different times during the mixture and dynamic crosslinking. The materials were characterized by some techniques, which allowed investigating mechanical, morphological, hardness, and swelling properties. Considering the used curing agents contents, the TPE‐Vs obtained by using Peroximon presented lower tensile strength, lower swelling degree, and remarkable lower deformation than those obtained with BMI/DCP system. The hardness properties were not significantly affected by the content of the curing agent, showing only a slight decrease when the Peroximon content was increased. The study of the evolution of morphology showed the rubber phase undergoes crosslinking after adding the curing agent. It could be observed by the increase of the torque and by the appearance of domains in the micrographs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Radiation processing of EPDM/PP blends

The effect of ionizing radiation on thermal oxidation of ethylene-propylene copolymer/polypropylene (EPDM/PP) was evaluated over the range of total gamma doses up to 250 kGy. The influence of irradiation dose on oxidation induction periods was investigated by oxygen uptake and thermal analysis on polymer samples containing various concentrations of components (100/0, 80/20, 40/60, 60/40, 20/80 and 100/0 w/w ). Drastic decrease in oxidation induction time was observed for low doses. The competition between crosslinking and scission has been examined on the basis of radical recombination on post-irradiation time. The influence of specimen formulations on oxidation induction time is discussed regarding to the contribution of antagonistic processes: crosslinking and oxidative degradation.     

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.     

动态硫化EPDM/PP共混型热塑性弹性体的流动性

研究了动态硫化EPDM／PP共混型热塑性弹性体的流动性。结果表明：选择合适的橡胶及塑料品种、橡塑共混比、软化剂用量及改性剂，可使物理力学性能良好的EPDM／PP共混胶获得较好的流动性。