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1.
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 (σf) 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 (εf) 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 (ηs) 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 ηs 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 相似文献
2.
In this paper, EPDM/mica composites were prepared by filling synthesized mica and natural mica separately into ethylene‐propylene diene terpolymer (EPDM) using melt blending technique. Microstructures, electrical properties, gas resistance, and mechanical properties of two EPDM/mica composites were investigated systematically. FTIR show that hydroxyl groups exist on the surface of the micas. These structural hydroxyls could be active sites conducive to the surface modification of mica. XRD analyses reveal that the natural mica is crystalline and the synthesized mica is amorphous. After being modified with silane coupling agent Si69, mica was only exfoliated into smaller micron agglomerates dispersing in EPDM, but the dispersion of amorphous synthesized mica was better. So the EPDM/synthesized mica composite possessed better mechanical property, electrical insulation property, and gas permeability resistance. It is expected that better improvement would be achieved, if mica is exfoliated further into nanosheets dispersing in the rubber matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
3.
High power ultrasound treatment of ethylene propylene diene monomer (EPDM) gum in extrusion process was found to affect its structure and properties. In comparison with the original EPDM gum, the ultrasonically treated samples were found to contain some amount of gel with sol having a higher molecular weight, possibly due to chain branching. Gel fraction and dynamic properties of the ultrasonically treated gums and their vulcanizates were measured as a function of processing conditions. Measurements of the stress–strain characteristics, dynamic properties, and hardness of EPDM vulcanizates prepared after treatment indicated a possibility of controlling their properties by varying processing parameters. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
4.
Combined Gel Permeation Chromatography—NMR Techniques in the Characterization of Petroleum Residuals
《分离科学与技术》2012,47(6):811-823
Abstract It has been shown that proton nuclear magnetic resonance spectra of fractions obtained by gel permeation Chromatography techniques can yield significant information in the characterization of petroleum residuals. Application of empirical relationships developed for the analysis of NMR spectra is shown to be useful when applied to gel permeation Chromatography fractions. Whole residues and a deasphaltened fraction have been separated and studied. Unit weights and aromaticities have been obtained by NMR and compared with molecular weights from vapor pressure osmometry measurements. In addition, supplemental information from infrared and mass spectrometry on GPC fractions has been used to characterize a “neutral” portion of the residue. Adsorption effects have caused an apparent shift in aliphatic and aromatic components as observed by NMR spectra suggesting that information relating to the mechanism of GPC separations, particularly in regard to factors other than molecular size which influence elution rates, might be obtained from petroleum residual characterizations. 相似文献
5.
Conifer fibers were used to reinforce polypropylene (PP). To improve the compatibility between the conifer fibers and the PP matrix, the fibers were either grafted with maleated PP (MAPP), treated by adding MAPP, or mixed with ethylene/propylene/diene terpolymer (EPDM). The treatments resulted in improved processing, as well as improvements in the thermal and mechanical properties of the resultant composites compared with the composites filled with untreated conifer fibers. Moreover, MAPP grafting and MAPP treating displayed more obvious benefits than EPDM treating in terms of thermal properties, processing flowability, and tensile strength improvements. EPDM treating also produced more significant benefits than either MAPP grafting or MAPP treating in terms of impact strength and tensile elongation improvements. These improvements were attributed to surface coating of the fibers when EPDM was used. In addition, the effect of the concentration of the conifer fibers on the properties of the composites and the difference between MAPP grafting and MAPP treating were evaluated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2833–2841, 2001 相似文献
6.
三元乙丙橡胶的研究及应用进展和市场新动态 总被引：1，自引：0，他引：1
阐述了乙丙橡胶(主要是三元乙丙橡胶(EPDM)和三元乙丙橡胶/聚丙烯(EPDM/PP))在国内外的发展、应用和消费近况,重点介绍国内近期的研究成果,并对EPDM/PP在汽车工业等领域应用概况和市场前景作了分析。 相似文献
7.
Anoma Thitithammawong Nattapon Uthaipan Banja Junhasavasdikul Charoen Nakason Ekwipoo Kalkornsurapranee 《应用聚合物科学杂志》2019,136(23):47613
Possibility of co-vulcanization of ethylene octene copolymer (EOC) and ethylene propylene diene terpolymer (EPDM) molecules was studied by assessing the curing characteristic and crosslinking kinetics of EOC and EPDM compounds. Regarding curing, the curing characteristics, cure rate index, and the torque difference (MH − ML) of the EPDM compound are quite similar to those of the EOC compounds at the curing temperature of 180 °C, especially when the EOC octene comonomer content is 5.9 or 9.7 mol %. The kinetic parameters E a and k were analyzed. The study showed that EOC with 9.7 mol % octene comonomer content is very suitable for blending with EPDM, as it has crosslinking kinetics similar to the EPDM. This observation confirms the possibility of chemical co-crosslinking at EPDM–EOC interfaces, especially at the curing temperature of 180 °C. Differential scanning calorimetry and dynamic mechanical analysis were also used to assess interfacial crosslinking. The lowest activation energy of vulcanization is found for the EPDM/EOC blend with 9.7 mol % octene comonomer contents. Furthermore, chemical co-crosslinking in combination with chain flexibility in the EPDM/EOC blend with 9.7 mol % octene comonomer contents give lower tan δ at room temperature than for the blends with octene comonomer contents of 5.9 and 16.9 mol %. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47613. 相似文献
8.
Summary: Polystyrene (PS) was toughened with ethylene‐propylene‐diene terpolymer (EPDM) in the presence of styrene‐butadiene‐styrene block copolymer (SBS). Incorporation of SBS into the PS/EPDM blends clearly improved the impact properties. For PS/EPDM/SBS (mass ratio: 69/21/10) blends, the notched Charpy impact strength reached a maximum value of 26.3 kJ/m2. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that SBS was distributed on the interface between PS and EPDM. Butanone extraction and FTIR analysis found that there was a grafting reaction between PS and EPDM phase during melt compounding. Shearing and processing rheological behaviors of blends were evaluated with a Haake capillary rheometer and a torque rheometer, respectively.
9.
10.
Polypropylene blends and composites with 5, 10, and 15 vol % of EPDM and 2, 4, and 6 vol % of untreated and treated wollastonite filler were examined by applying different techniques. Elastomeric ethylene/propylene/diene terpolymer (EPDM) component and wollastonite influenced the crystallization process of isotactic polypropylene (iPP) matrix in different ways. The nucleation of hexagonal β‐iPP, the increase of overall degree of crystallinity, and crystallite size of iPP were more strongly affected by wollastonite than the addition of EPDM was. Both ingredients also differently influenced the orientation of α‐form crystals in iPP matrix. Wollastonite increased the number of a*‐axis‐oriented α‐iPP lamellae plan parallel to the sample surface, whereas the addition of EPDM reoriented the lamellae. The orientation parameters of ternary composites exhibited intermediate values between those for binary systems because of the effects of both components. EPDM elastomer considerably affected well‐developed spherulitization of iPP, increasing the spherulite size. Contrary to EPDM, because of nucleating ability or crystal habit, wollastonite caused significantly smaller iPP spherulites. Small spherulites in ternary iPP/EPDM/wollastonite composites indicated that the wollastonite filler (even in smallest amounts) exclusively determined the morphology of ternary composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 4072–4081, 2004 相似文献
11.
The dynamic mechanical studies, impact resistance, and scanning electron microscopic studies of ethylene propylene diene terpolymer–poly(vinyl chloride) (EPDM–PVC) and methyl methacrylate grafted EPDM rubber (MMA‐g‐EPDM)–PVC (graft contents of 4, 13, 21, and 32%) blends were undertaken. All the regions of viscoelasticity were present in the E′ curve, while the E″ curve showed two glass transition temperatures for EPDM–PVC and MMA‐g‐EPDM–PVC blends, and the Tg increased with increasing graft content, indicating the incompatibility of these blends. The tan δ curve showed three dispersion regions for all blends arising from the α, β, and Γ transitions of the molecules. The sharp α transition peak shifted to higher temperatures with increasing concentration of the graft copolymer in the blends. EPDM showed less improvement while a sixfold increase in impact strength was noticed with the grafted EPDM. The scanning electron microscopy micrographs of EPDM–PVC showed less interaction between the phases in comparison to MMA‐g‐EPDM–PVC blends. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1959–1968, 1999 相似文献
12.
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 相似文献
13.
《国际聚合物材料杂志》2012,61(9):643-662
Paper sludge was used as a filler in PP/EPDM composites and 3-aminopropyl triethoxysilane (3-APE) was used in this study as a coupling agent. The effects of filler loading and 3-APE on the mechanical properties, water absorption, morphology, and thermal properties of the composites were investigated. It was found that incorporation of a silane coupling agent (3-APE) increased the stabilization (equilibrium) torque, tensile strength, and Young's modulus but decreased the elongation at break and water absorption. Scanning electron microscopy (SEM) study of the tensile fracture surface of the composites indicated that the presence of 3-APE increased the interfacial interaction between paper sludge and PP/EPDM matrix. The addition of a silane coupling agent also increased the crystallinity of PP and thermal stability of PP/EPDM/PS composites. 相似文献
14.
PP/EPDM热塑性弹性体结晶与熔融行为研究 总被引：1，自引：0，他引：1
采用动态光交联法制备了PP／EPDM[聚丙烯／（乙烯／丙烯／二烯）共聚物]热塑性弹性体。运用广角X射线衍射（WAXD），偏光显微镜（POM）与差示扫描量热仪（DSC）对PP的结晶形态及结晶与熔融行为进行表征。结果表明，EPDM的加入妨碍PP形成完善的球晶，而动态光交联体系中PP的球晶更不完善；动态光交联对PP的结晶温度及熔点影响不大，结晶度低于未交联体系的。 相似文献
15.
摘要：以聚丙烯(PP)和三元乙丙橡胶(EPDM)等为原料,采用完全动态硫化共混技术制备EPDM/PP热塑性弹性体(TPV),使用毛细管流变仪对TPV熔体的流变特性进行测试。分别研究了剪切速率、挤出温度对黏度、剪切应力和挤出胀大比的影响,以及不同条件下熔体流过毛细管口模时流速对压力降的影响。结果表明,TPV熔体是假塑性流体,其剪切应力随剪切速率增大而增大,随挤出温度的升高而降低;黏度随剪切速率和挤出温度的增大而降低;挤出胀大比则随剪切速率和挤出温度的增大而增大;毛细管口模的压力降也随流速和毛细管口模长度的增大而增大。 相似文献
16.
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 相似文献
17.
采用动态全硫化方法制备三元乙丙橡胶(EPDM)/聚丙烯(PP)热塑性弹性体(TPV),研究剪切强度、硫黄用量、促进剂TMTD用量和并用促进剂DM对相反转及TPV物理性能的影响。结果表明:提高剪切强度(转速)有利于相反转发生,但转速过高会使相反转失败,TPV综合物理性能随着转速提高呈现先减小后增大的趋势;适当增大硫黄或促进剂TMTD用量均对TPV的相反转过程产生促进作用,并使反转时间缩短;给定促进剂TMTD用量,硫黄用量对相反转的促进作用存在最佳值,反之亦然;给定硫黄/促进剂TMTD用量,并用促进剂DM会使相反转时间延长甚至失败。 相似文献
18.
研究了增容剂二元乙丙橡胶接枝马来酸酐(EPM-g-MAH)和丁腈橡胶/甲基丙烯酸缩水甘油酯的共聚物(NBR-GMA)对NBR/EPDM共混胶力学性能和相形态结构的影响。结果表明,加入EPM-gMAH/NBR-GMA并用物后共混胶凝胶含量明显增大。随着增容剂用量的增大,共混胶相形态结构得到明显改善,力学性能有所提高,且共混胶的耐热性能好于耐油性能。共混胶DMA曲线表明,增容剂对NBR/EPDM共混胶有较好增容作用。 相似文献
19.
Ethylene‐propylene diene rubber (EPDM) and isotactic polypropylene (iPP) blends have widest industrial applications that require a degree of flame retardancy. Halogen‐free intumescent technology based on phosphorous salt is a significantly advanced approach to make the polymer flame‐retardant. Both ammonium polyphosphate and ethylenediamine phosphate are important intumescent compounds. Their combination with carbonific and spumific agents were studied in binary blends of EPDM/PP. The polymer system was vulcanized online during melt mixing. Intumescent flame‐retardant polymer systems exhibit good flame‐retardancy with optimum comparable physiomechanical, electrical, and fluid resistance properties, including lower smoke emission, which is essential to protect people because the visibility remains unaffected in the event of fire. Pronounced charring and intumescent effect appear to enhance the flame‐retardancy of the polymers. Possible expected intumescent mechanism is proposed based on the nonpyrolysis mechanism for the flame‐retarded polymer and the intumescent components. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 407–415, 2004 相似文献
20.
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。 相似文献