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     

动态硫化法制备三元乙丙橡胶/聚酰胺热塑性弹性体

采用动态硫化技术制备了三元乙丙橡胶(EPDM)／聚酰胺(PA)热塑性弹性体,研究了增容剂种类及用量、硫化体系及其用量、加料顺序、PA用量对其性能的影响,用扫描电镜分析了其相态结构。结果表明,用13份(质量份,下同)的氯化聚乙烯作为增容剂时,对该共混体系的增容效果最好;硫黄硫化体系是EPDM／PA热塑性弹性体的最佳硫化剂,当硫黄用量为2份时,既保证了该热塑性弹性体中的橡胶相能充分交联,又可避免过硫化对产品性能造成的负面影响;PA用量为35份的EPDM／PA热塑性弹性体具有良好的力学性能、耐溶剂性能和耐热老化性能;EPDM以平均粒径为2～5μm的粒子形态均匀分布于PA连续相中。     

Rheological behavior and processability of polypropylene blends with rubber ethylene propylene diene terpolymer

A study of the dynamic complex and steady shear viscosity of isotactic polypropylene (iPP), ethylene–propylene diene terpolymer rubber (EPDM) and three different blends of both polymers are presented over a range of temperatures and frequencies. Moreover, the processability of these materials is studied through torque measurements during blend mixing. The results obtained show that the viscosity gradually increases with rubber content in the blend and decreases with both temperature and frequency. Plots of η″ versus η′ (Cole–Cole plots) show that the blend with the lower rubber content (25%), has a certain rheological compatibility with neat PP. Furthermore, torque curves measured during blend mixing confirm these results, demonstrating that the blend with 25% of elastomer has a similar behavior of iPP during processing. To analyze the morphological structure of the blends, a dynamic mechanical analysis of the solid state is also presented. It is observed that the blends have two distinct values of T_g close to the corresponding values of the pure polymers, confirming that this type of blends based on a semicrystalline polymer and an amorphous elastomer forms a two‐phase system with a limited degree of miscibility between both components. In addition, the polymer present with the higher concentration forms the continuous phase and controls the rheological properties of the blend. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1–10, 2001     

Transport behavior of aromatic hydrocarbons through high density polyethylene/ ethylene propylene diene terpolymer blends

Membrane based separation technology is currently regarded as a new frontier of chemical engineering and widely used for the purification, concentration and fractionation of fluid mixtures. Polymer blend membranes are promising materials that can overcome the difficulties associated with homopolymer systems and hence the selection of polymer blend membrane as a novel material for various applications is worth probing. Transport properties of aromatic hydrocarbons through a new class of membranes from blends of high density polyethylene (HDPE) and ethylene propylene diene terpolymer rubber (EPDM) have been investigated at different temperatures to understand the effect of physical and chemical nature of the polymer blend on the transport phenomena. The effects of blend ratio, temperature and penetrant size on the sorption properties were studied. The equilibrium solvent uptake decreases with an increase in concentration of HDPE, in the blends. Relationship between transport behavior and the morphology of the system was examined. The mechanism of transport has been analyzed and found that the mode of transport is close to Fickian. The sorption data have been used to estimate the transport coefficients and various kinetic parameters of sorption.     

The effects of dynamic vulcanization and compatibilizer on properties of paper sludge‐filled polypropylene/ethylene propylene diene terpolymer composites

The effects of dynamic vulcanization (DV) and dynamic vulcanization plus compatibilizer (DVC) of paper sludge (PS) filled polypropylene/ethylene propylene diene terpolymer (PP/EPDM) composites on torque development, mechanical properties, water absorption, morphology, and thermal properties were studied. Results show that DV and DVC composites exhibit higher stabilization torque than unvulcanized composites (UV). The dynamic vulcanized (DV) and dynamic vulcanized plus compatibilizer (DVC) composites exhibit higher tensile strength, elongation at break, and Young's modulus but lower water absorption than unvulcanized composites. The scanning electron microscopy (SEM) study of tensile fracture surface of DV and DVC composites shows the improved interfacial interaction between PS and PP/EPDM matrix. The DV and DVC composites also exhibit better thermal stability and higher crystallinity than unvulcanized PP/EPDM/PS composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Properties of copolymer-type polyacetal/ethylene–propylene–diene terpolymer blends

Two kinds of polymer blends, polyacetals (POMs) and ethylene–propylene–diene terpolymer (EPDM), have been prepared by mechanical blending. The rubbery EPDM was added to the rigid POM matrix to increase toughness. The mechanical, physical, thermal, dynamic mechanical, and morphological properties of these samples have been measured. The notched Izod impact strength and the elongation of the blends reaches a maximum at 7.5 wt % EPDM content. Scanning electron micrographs (SEM) showed that the domain sizes of EPDM vary from 0.25 to 1.0 μm and were independent of the composition. The POM/EPDM blends were determined to be immiscible by SEM, but showed single T_g behavior as determined by differential scanning calorimetry (DSC) and dynamic mechanical analyses up to 7.5 wt % EPDM. Because of that, the T_g's of POM and EPDM were very similar in value. © 1993 John Wiley & Sons, Inc.     

Mechanical,thermal, and morphological characteristics of compatibilized and dynamically vulcanized polyoxymethylene/ethylene propylene diene terpolymer blends

Dynamically vulcanized blends of polyoxymethylene (POM) and ethylene propylene diene terpolymer (EPDM) with and without compatibilizer were prepared by melt mixing in a twin screw extruder. Maleic anhydride (MAH) grafted EPDM (EPDM‐g‐MAH) has been used as a compatibilizer. Dicumyl peroxide was used for vulcanizing the elastomer phase in the blends. Mechanical, dynamical mechanical, thermal, and morphological properties of the blend systems have been investigated as a function of blend composition and compatibilizer content. The impact strength of both dynamically vulcanized blends and compatibilized/dynamically vulcanized blends increases with increase in elastomer content with decrease in tensile strength. Dynamic mechanical analysis shows decrease in tanδ values as the elastomer and compatibilizer content increased. Thermograms obtained from differential scanning calorimetric studies reveal that compatibilized blends have lower T_m values compared to dynamically vulcanized blends, which confirms strong interaction between the plastic and elastomer phase. Scanning electron microscopic observations on impact fractured surface indicate reduction in particle size of elastomer phase and its high level of dispersion in the POM matrix. In the case of compatibilized blends high degree of interaction between the component polymers has been observed. POLYM. ENG. SCI., 47:934–942, 2007. © 2007 Society of Plastics Engineers     

动态硫化对三元共聚尼龙/SAN/NBR共混物的影响

三元共聚尼龙/SAN/NBR（50/25/25,质量比）共混物在酚醛树脂的作用下进行动态硫化。当硫化剂用量大于8份（质量份,下同）时可制得具有均衡力学性能特别是超高韧性的共混合金。用扫描电镜对在液氮中淬断并用四氢呋喃刻蚀的分别含0,4,8,10份酚醛树脂的试验进行分析,发现分散相粒径随硫化剂用量的增加而减小,粒径分布变得更加均匀。     

用于变压器的丁腈橡胶/三元乙丙橡胶并用胶

为了实现丁腈橡胶(NBR)与三元乙丙橡胶(EPDM)并用作为变压器密封材料,研究了并用比、增容剂及硫化体系种类对NBR/EPDM并用胶的影响。结果表明,NBR/EPDM(质量比)为70/30时并用胶具有良好的耐臭氧性能与最佳的综合物理机械性能;在并用胶中加入增容剂乙华平8784可以改善其物理机械性能;使用过氧化物硫化体系硫化并用胶的物理机械性能比使用硫黄/促进剂硫化体系者更好。     

Studies on dynamic and static crosslinking of ethylene vinyl acetate and ethylene propylene diene tercopolymer blends

The effect of blend ratio on the crosslinking characteristics of ethylene vinyl acetate and ethylene propylene diene tercopolymer (EVA‐EPDM) blends was studied by differential scanning calorimetry and a torque rheometer (Rheocord‐90). The activation energy decreases with an increase in EVA content in the blend. The cure rate increases whereas the optimum cure time and energy consumption for curing decrease with an increase in the EVA/EPDM ratio. The dynamic curing obtained by the torque rheometer is very fast compared to the static curing obtained by differential scanning calorimetry. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2756–2763, 1999     

Study on the ablative properties of ethylene propylene diene terpolymer/silsesquioxane insulation materials

Octaphenylsilsesquioxane (OPS), polyphenylsilsesquioxane (PPSQ), and octavinylsilsesquioxane (OVP) have been incorporated into ethylene propylene diene terpolymer (EPDM) in order to study their effects on the ablative properties of the respective EPDM composites. The results show that PPSQ and OVP serve as effective ablative additives for EPDM composites. The linear ablation rates of EPDM composites with 4.4 wt % OVP or PPSQ were reduced by 21 or 16.5%, respectively, compared with the control sample. Moreover, OVP and PPSQ also improved the flame retardancy and suppressed smoke emission. The heat release rate of EPDM composite with 4.4 wt % OVP was measured as 90.6 kW m⁻², 17% lower than that of the control sample, and the same amount of PPSQ reduced the total smoke release from 1946 to 1497 m² s⁻¹. Thermogravimetric analysis results showed EPDM/OVP composite to leave a higher residual mass than the calculated value. Besides, scanning electron microscopy, cone calorimetry (CONE), and BET tests showed that the chars formed during the ablation of EPDM composites containing OVP and PPSQ had better structural stability and thermal stability owing to the fact that they were denser and more homogeneous. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48365.     

助交联剂对三元乙丙橡胶过氧化物硫化的影响

分别采用三烯丙基异氰脲酸酯(TAIC)、三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)以及高乙烯基聚丁二烯(HVPBd)作为过氧化物硫化三元乙丙橡胶(EPDM)的助交联剂,研究其对EPDM胶料硫化特性及硫化胶力学性能的影响。结果表明,3种助交联剂的添加能明显促进硫化程度,硫化胶的硬度和定伸应力均明显提高,添加TAIC的EPDM混炼胶硫化程度最高,但添加TMPTMA使胶料的焦烧安全性变差,而添加HVPBd的EPDM胶料降解程度最低。通过一级动力学模型及自催化反应模型研究EPDM硫化动力学行为时发现,助交联剂类型影响胶料的硫化反应速率,其中TMPTMA能明显促进硫化反应速率,TAIC次之,而HVPBd几乎没有影响,但硫化反应表观活化能由于助交联剂的添加均出现降低,其中添加TAIC胶料的表观活化能最低。     

动态硫化对三元乙丙橡胶/聚丙烯共混体系等温结晶行为和形态结构的影响

研究了三元乙丙橡胶/聚丙烯(EPDM/PP)共混物和动态硫化EPDM/PP热塑性弹性体(TPV)的等温结晶行为及形态结构,并用Avrami方程对其进行等温结晶动力学分析。结果表明,EPDM/PP共混物和EPDM/PP TPV的等温结晶行为符合Avrami方程,在相同的结晶温度下,TPV比共混物的Avrami指数小,半结晶时间短,结晶速率常数大;EPDM/PP共混物为双连续相结构,而EPDM/PP TPV是以硫化的细小橡胶颗粒为分散相、PP为连续相的"海-岛"结构,橡胶颗粒尺寸约为0.5μm。     

A solution blending route to ethylene propylene diene terpolymer/layered double hydroxide nanocomposites

Ethylene propylene diene terpolymer (EPDM)/MgAl layered double hydroxide (LDH) nanocomposites have been synthesized by solution intercalation using organically modified LDH (DS-LDH). The molecular level dispersion of LDH nanolayers has been verified by the disappearance of basal XRD peak of DS-LDH in the composites. The internal structures, of the nanocomposite with the dispersion nature of LDH particles in EPDM matrix have been studied by TEM and AFM. Thermogravimetric analysis (TGA) shows thermal stability of nanocomposites improved by ≈40 °C when 10% weight loss was selected as point of comparison. The degradation for pure EPDM is faster above 380 °C while in case of its nanocomposites, it is much slower.     

Natural rubber/ethylene propylene diene blends for high insulation iron crossarms

This research studied the composition and behavior of natural rubber (NR) and ethylene propylene diene monomer (EPDM) blends at various carbon black concentrations (0–30 phr) in terms of electrical resistivity, dielectric breakdown voltage testing, and physical properties. The blends having electrical properties suitable for application in high‐insulation iron crossarms were selected for investigation of compatibility and increased physical properties. The effect of the homogenizing agent concentration on improvement of compatibility of blends was studied by scanning electron microscopy, pulsed nuclear magnetic resonance spectroscopy, and rheology techniques. We also examined mechanical properties such as tensile strength, tear strength, elongation at break, and hardness. The NR/EPDM blends filled with a fixed concentration of silica were investigated for ozone resistance. A carbon black content as high as 10 phr is still suitable for the insulation coating material, which can withstand electrical voltage at 10 kVac. Addition of the homogenizing agent at 5 phr can improve the mechanical compatibility of blends, as evidenced by the positive deviation of shear viscosity of the rubber blend, that is, the calculated shear viscosity being higher than that of experimental data. Moreover, the pulsed NMR results indicated that the spin‐spin relaxation (T₂) of all three components of the rubber blend was compressed upon the addition of the homogenizing agent. The ratio of NR/EPDM in the blend to best resist the ozone gas is 80/20 with the addition of silica of 30 phr into the blend. Also, the NR/EPDM filled with silica had a decreased change in thermal and mechanical properties of blends after thermal aging. The synergistic effect of silica content and high NR content (80) in 20 phr EPDM could improve antioxidation by ozone in the absence of a normal antioxidant for natural rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3401–3416, 2004     

Ethylene propylene diene terpolymer/ethylene vinyl acetate/layered silicate ternary nanocomposite by solution method

A new ternary nanocomposite has been developed using ethylene propylene diene terpolymer (EPDM), ethylene vinyl acetate (EVA‐45) copolymer, and organically modified layered silicate (16 Me‐MMT) from sodium montmorillonite (Na⁺‐MMT). Wide angle X‐ray diffraction and transmission electron microscopic analysis confirmed the intercalation of the polymer chains in between the organosilicate layers and the nanoscale distribution of 16 Me‐MMT in polymer matrix, respectively. The measurement of mechanical properties for 2–8 wt% of 16 Me‐MMT loadings showed a significant increase in tensile strength, elongation at break, and modulus at different elongations. Such an improvement in mechanical properties has been correlated based on the fracture behavior of nanocomposite by SEM analysis. Thermal stability of EPDM/EVA/layered silicate ternary nanocomposites also showed substantial improvements compared with the neat EPDM/EVA blend, confirming thereby the formation of a high performance nanocomposite. POLYM. ENG. SCI., 46:437–843, 2006. © 2006 Society of Plastics Engineers     

乙丙橡胶生产工艺与技术

乙丙橡胶以其独特的性能,在汽车工业、建筑行业、油品添加剂、塑胶跑道等领域有广泛的应用。本文主要介绍了乙丙橡胶生产技术、乙丙橡胶产品牌号、性能以及应用领域,结合现有的乙丙橡胶科研情况,阐述了乙丙橡胶催化剂的研发、核壳型球状乙丙橡胶、原位聚合法合成长链支化乙丙橡胶、乙烯、丙烯与其他二烯烃的共聚物研究进展;详细研究了乙丙橡胶溶液聚合工艺技术中的聚合技术、单体回收技术、失活洗涤技术、闪蒸提浓技术以及国外公司在中国建设装置的生产技术情况。提出了乙丙橡胶的关键生产技术是乙丙橡胶聚合所采用的催化剂体系,通过催化体系的更新换代,开发不同用途的乙丙橡胶,以满足开发高性能材料的要求。在此基础上,指出了今后乙丙橡胶新的催化体系开发将成为未来的研究重点。     

Negative air ions releasing properties of tourmaline contained ethylene propylene diene terpolymer/polypropylene thermoplastic elastomers

The releasing properties of negative air ions of tourmaline contained polypropylene (PP) and ethylene propylene diene terpolymer/polypropylene (EPDM/PP) composite films under varying testing conditions were investigated in this study. It is interesting to note that the C_ion− values of EPDM/PP/tourmaline specimens tested at varying conditions are significantly higher than those of the PP/tourmaline specimens with the same loadings of tourmaline powders. Moreover, all C_ion− values of PP/tourmaline and EPDM/PP/tourmaline film specimens tested at dynamic impact mode are significantly higher than those of the corresponding specimens tested at static mode but the same temperature. A beneficial temperature effect on C_ion− values of the PP/tourmaline and EPDM/PP/tourmaline film specimens tested at static and dynamic impact conditions was found. To understand these interesting negative air ion properties of PP/tourmaline and EPDM/PP/tourmaline film specimens, energy dispersive X-rays analysis of the tourmaline powders, scanning electron microscope morphology, and tensile property analysis of the PP/tourmaline and EPDM/PP/tourmaline film specimens were performed. Possible reasons account for the interesting negative air ion properties of the PP/tourmaline and EPDM/PP/tourmaline film specimens are discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Effect of some curatives on the properties of ethylene propylene diene rubber/polyethylene blends

A series of ethylene propylene diene rubber/polyethylene (EPDM/PE) blends has been prepared containing different weight fractions of PE up to 0.66. The blends were vulcanized with a sulphur system N-cyclohexyl-2-benzthiazol sulphenamide/sulphur (CBS/S), and a non-sulphur-system dicumyl peroxide (DCUP). The concentration of the latter has been changed from 1.5 phr up to 6 phr calculated on the total weight of the blend composition. It has been found that the maximum torque obtained from rheographs for blends vulcanized with the CBS/S system decreases markedly with increasing PE concentration in comparison with those vulcanized with peroxide. The E modulus obtained from the stress–strain diagram at 110 °C showed the role played by the crosslinking of PE, the E modulus for blends vulcanized by peroxide being higher than for samples vulcanized with CBS/S. In contrast, the values of E modulus of both samples are practically the same at room temperature and attain more than 40 MPa depending on the composition. The tensile strength at room temperature strongly increases with increasing the weight fraction of PE. It has also been confirmed that the melting point of the crystalline phase of PE decreases with increasing crosslinking density of PE. The shear modulus obtained from dynamic mechanical measurements is in accordance with that obtained from static mechanical measurements. © 1999 Society of Chemical Industry     

过氧化物体系中天然橡胶/三元乙丙橡胶并用胶的共硫化

研究了以过氧化二异丙苯(DCP)/助硫化剂为硫化体系分别硫化天然橡胶(NR)/三元乙丙橡胶(EPDM)以及NR/预硫化EPDM并用胶的性能,考察了EPDM混炼胶的硫化特性,对并用硫化胶进行了.差示扫描量热分析.结果表明,NR/EPDM并用胶在使用DCP/助硫化荆硫化体系时具有较好的共硫化性;EPDM经预硫化后可以将配合剂固定其中,并能增加EPDM的硫化活性,提高了与NR并用胶的共硫化性.