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     

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。     

动态硫化PP/EPDM的拉伸行为

采用一步法和母料法制备了动态硫化ＰＰ／ＥＰＤＭ,进行了材料拉伸行为的研究,结果表明,分散相ＤＰＤＭ可提高材料的延伸性和韧性,ＰＰ的分子量决定了Ｆｔ、σｙ和σｐ;而拉伸后期是否出现σｂ和εｔ的二次屈服,则和ＥＰＤＭ的交联和形态有关。采用母料法和并用助交联剂,可达到增韧和保持刚性的目的。     

工艺因素对PP／EPDM动态硫化作用的研究

通过冲击试验、熔体指数、共混平衡扭矩（ＴＱ）和交联程度测试以及扫描电镜观察等手段,研究了引发剂用量和动态硫化时间两大工艺因素对ＰＰ／ＥＰＤＭ动态硫化过程以及动态硫化物性能的影响。结果显示,引发剂ＤＣＰ用量以能引发全部ＥＰＤＭ交联并稍过量为宜;硫化时间应控制在引发剂半衰期的６～７倍较为理想     

动态硫化EPDM/PP热塑性弹性体的制备

研究了三元惭丙橡胶／聚丙烯（ＥＰＤＭ／ＰＰ）共混型热塑性体的配方组成,探讨了其制备工艺,测定了其力学性能和加工流动性,并研究了其对ＰＰ的增韧作用效果,结果表明,所制备的ＥＰＤＭ／ＰＰ性能与国外产品相当,且其对ＰＰ的增韧效果优于传统的ＥＰＤＭ／ＰＰ母料。     

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。     

动态全硫化EPDM／PP共混型热塑性弹性体制备工艺研究

对ＥＰＤＭ／ＰＰ 共混型热塑性弹性体的产生和发展,作了简单回顾,介绍了动态全硫化ＥＰＤＭ／ＰＰ 共混型热塑性弹性体的制备原则,重点讨论了这类热塑性弹性体的制备工艺。     

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     

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。     

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。     

In‐situ ultrasonic compatibilization of unvulcanized and dynamically vulcanized PP/EPDM blends

Dynamically vulcanized PP/EPDM blends were treated by high‐intensity ultrasonic waves during extrusion. These blends were compared with unvulcanized PP/EPDM blends that were treated by ultrasound during extrusion and then dynamically vulcanized. Die pressure and power consumption were measured. The effects of different gap sizes, ratio of components, and number of ultrasonic horns were investigated. The rheological properties, morphology and mechanical properties of the blends with and without ultrasonic treatment were compared. The results obtained indicated that ultrasonic treatment induced thermo‐mechanical degradation, causing enhanced molecular transport and chemical reactions at the interfaces, thus leading to in‐situ compatibilization, which is evident by the morphological and mechanical property studies. Processing conditions were established for enhanced in‐situ compatibilization of the PP/EPDM blends that were either originally dynamically vulcanized and then ultrasonically treated or first treated and then dynamically vulcanized. Polym. Eng. Sci. 44:2019–2028, 2004. © 2004 Society of Plastics Engineers.     

Optimized processing conditions for the preparation of dynamically vulcanized EPDM/PP thermoplastic elastomers containing PP resins of various melt indexes

We have investigated the mechanical and morphological properties of un‐vulcanized and dynamically vulcanized ethylene propylene diene terpolymer/polypropylene (EPDM/PP) thermoplastic elastomers prepared under various processing conditions and possessing various compositions. After melt‐blending EPDM and PP resins twice in a twin‐screw extruder, the values of tensile strength (σ_f) of the un‐vulcanized EPDM/PP samples were at most equal to that of the pure EPDM specimen, but were much lower than those of the pure PP specimens. The elongations at break (ε_f) of the un‐vulcanized EPDM/PP samples were, however, dramatically higher than those of their respective virgin PP resins, and they improved significantly upon increasing the shear viscosity (η_s) of the PP resins. The tensile properties of the dynamically vulcanized EPDM/PP samples were significantly better than those of the corresponding un‐vulcanized EPDM/PP specimens. Similar to the behavior of the un‐vulcanized EPDM/PP specimens, the tensile properties of the dynamically vulcanized EPDM/PP specimens were optimized when prepared at a screw rate of 115 rpm. Morphological analysis revealed that the un‐vulcanized and dynamically vulcanized EPDM/PP specimens both featured many EPDM domains finely dispersed in continuous PP matrices. Such domains were present on the surfaces of the dynamically vulcanized EPDM/PP specimens; the relative sizes of the vulcanized EPDM domains were minimized when the vulcanized EPDM/PP specimens were prepared at the optimal screw rate (115 rpm). In fact, under these conditions, the average sizes of the vulcanized EPDM domains decreased upon increasing the values of η_s of the PP resins used to prepare the vulcanized EPDM/PP specimens. To understand these interesting tensile and morphological properties of the un‐vulcanized and dynamically vulcanized EPDM/PP specimens, we measured the rheological properties of the base polymers and performed energy‐dispersive x‐ray (EDX) analyzes of the compositions of the un‐vulcanized and dynamically vulcanized EPDM/PP specimens. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

共混工艺对EPDM/PP性能的影响

研究了共混时间和5种共混方法对动态硫化EPDM(乙烯／N烯／二烯共聚物)／PP的结晶相态结构及力学性能的影响。结果表明，随着共混时间的延长。EPDM／PP体系的力学性能先变好后变差。当共混时间为5min时EPDM／PP体系的力学性能最佳；无论是采用哪种共混方法，均能形成完全硫化的弹性体相，但力学性能差别明显。     

不同助交联剂在动态硫化PP／EPDM弹性体中的作用

分析了不同的助交联剂对过氧化物硫化聚丙烯／乙烯-丙烯-二烯共聚物（EPDM）热塑性弹性体力学性能、流变性能、热稳定性能的影响，结果表明：不同的助交联剂均有提高凝胶含量和改善聚丙烯（PP）降解程度、提高力学性能的用途。其中，三羟甲基丙烷二烯丙基醚（TMPDE）作为过氧化物硫化PP／EPDM的助交联剂，相比三烯丙基异氰脲酸酯（TAIC）、邻苯二甲酸二烯丙酯（DAP）和三羟甲基丙烷三丙烯酸酯（TMPTA），所得制品综合力学性能优异，热稳定性能提高，流动性改善，微观结构均匀。     

Structure and properties of peroxide dynamically vulcanized polypropylene/ethylene–propylene–diene/zinc dimethacrylate composites

Peroxide dynamically vulcanized thermoplastic olefin (TPO) based on polypropylene (PP)/ethylene–propylene–diene (EPDM) loaded with zinc dimethacrylate (ZDMA) was prepared. The addition of ZDMA improved the complex viscosity of the resulting materials in the melt state significantly, as determined from oscillatory rheology analyses. Dynamic mechanical analysis (DMA) and transmission electron microscopy (TEM) examinations were performed to evaluate the structure of the PP/EPDM/ZDMA composite. Atomic force microscope (AFM) and scanning electron microscopy (SEM) were used to study the morphology. The degree of crystallinity was evaluated using X‐ray diffraction method (XRD). The results revealed that incorporation of ZDMA resulted in a size reduction of the rubber droplets and improved the compatibility between rubber and PP phases. The nanoparticles of the polymerized ZDMA (PZDMA) served as an effective nucleating agent for the crystallization of PP. The rheological properties and mechanical properties were improved by ZDMA. Particularly, the izod impact strength of the PP/EPDM/ZDMA (80/20/6, w/w) composite is nearly 2 times higher than the PP/EPDM (80/20, w/w) and 12 times higher than the PP; besides, the elongation at break of the PP/EPDM/ZDMA (80/20/6, w/w) is 3 times higher than that of the PP/EPDM (80/20, w/w) and 6 times higher than the PP. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

动态硫化三元乙丙橡胶(EPDM)/聚丙烯(PP)热塑性弹性体的力学性能

研究了双螺杆挤出机制备EPDM/PP热塑性弹性体的工艺条件对其力学性能的影响,结果显示,当橡塑比为60/40.EPDM与PP预混合两次,双螺杆挤出机转速约9.5Hz,硫化剂的量为10份时,热塑性弹性体有较好的力学性能。     

硫化体系对动态硫化EPDM/PP热塑性弹性体性能的影响

比较了三种硫化体系对动态硫化EPDM/PP热塑性弹性体力学性能及加工性能的影响及其应用前景,结果表明:酚醛树脂硫化体系最具有发展潜力。并介绍了国内外动态硫化EPDM/PP热塑性弹性体硫化体系的新进展     

PP/EPDM热塑性弹性体动态硫化阻燃材料制备及性能研究

研究了聚丙烯/三元乙丙橡胶(PP/EPDM)体系在过氧化二异丙苯(DCP)、硫磺(S)和酚醛树脂(PF)三种不同硫化条件下的动态硫化过程。探讨了膨胀型阻燃剂三聚氰胺磷酸盐(MP)和双季戊四醇(DPER)对PP/EPDM动态硫化体系力学性能和阻燃性能的影响。结果表明:在加入阻燃剂的情况下,PP/EPDM体系的阻燃性能得到了改善,但体系的力学性能下降较多。     

Miscibility of blends of ethylene‐propylene‐diene terpolymer and polypropylene

The miscibility of polymers is not only an important basis for selecting a proper blending method, but it is also one of the key factors in determining the morphology and properties of the blends. The miscibility between ethylene‐propylene‐diene terpolymer (EPDM) and polypropylene (PP) was explored by means of dynamic mechanical thermal analysis, transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The results showed that a decrease in the PP content and an increase of the crosslinking density of EPDM in the EPDM/PP blends caused the glass‐transition temperature peaks of EPDM to shift from a lower temperature to higher one, yet there was almost no variance in the glass‐transition temperature peaks of PP and the degree of crystallinity of PP decreased. It was observed that the blends prepared with different mixing equipment, such as a single‐screw extruder and an open mill, had different mechanical properties and blends prepared with the former had better mechanical properties than those prepared with the latter. The TEM micrographs revealed that the blends were composed of two phases: a bright, light PP phase and a dark EPDM phase. As the crosslinking degree of EPDM increased, the interface between the phases of EPDM and PP was less defined and the EPDM gradually dispersed in the PP phase became a continuous phase. The results indicated that EPDM and PP were both partially miscible. The mechanical properties of the blends had a lot to do with the blend morphology and the miscibility between the blend components. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 315–322, 2002