气相聚合三元乙丙橡胶

传统的合成橡胶一般采用液相聚合 (包括均聚和共聚 )的方法制造 ,即把单体溶解或分散在溶剂或水中 ,进行聚合。而烯烃类塑料可采用气相聚合方法。从 2 0世纪九十年代起 ,美国联合碳化公司将这一技术移植到以烯烃类单体为原料的三元乙丙橡胶中 ,并获得成功 ,可谓独树一帜 ,实现了橡胶和塑料合成工艺的一体化 ,开辟了弹性体生产技术的新途径。按照传统的合成方法 ,三元乙丙橡胶的合成工艺由聚合、脱气及干燥后处理等三部份组成。其中以脱气部份的环节最多 ,其中包括单体回收 ,溶剂 稀释剂回收、挤出脱水和干燥等工序。脱气阶段的流程最长 ,能…     

乙丙橡胶的合成及其发展现状

乙丙橡胶因其结构可控、主链饱和、耐老化好等优异性能,广泛应用于汽车配件、电线电缆、建筑材料、耐热胶管、密封构件等相关领域。从催化体系和聚合工艺两方面系统介绍了合成乙丙橡胶的研究进展,重点阐述了钒系和钛系Ziegler-Natta催化剂,普通型、桥连型以及限制几何构型茂金属催化剂,负载型茂金属催化剂以及非茂催化剂及其催化乙丙共聚合的特征;同时介绍了溶液聚合、悬浮聚合以及气相聚合的工艺流程及特点,以及乙丙橡胶的若干新品种;最后展望了乙丙橡胶的未来发展趋势。     

乙丙橡胶的合成及其发展现状

乙丙橡胶因其结构可控、主链饱和、耐老化好等优异性能,广泛应用于汽车配件、电线电缆、建筑材料、耐热胶管、密封构件等相关领域。从催化体系和聚合工艺两方面系统介绍了合成乙丙橡胶的研究进展,重点阐述了钒系和钛系Ziegler-Natta催化剂,普通型、桥连型以及限制几何构型茂金属催化剂,负载型茂金属催化剂以及非茂催化剂及其催化乙丙共聚合的特征;同时介绍了溶液聚合、悬浮聚合以及气相聚合的工艺流程及特点,以及乙丙橡胶的若干新品种;最后展望了乙丙橡胶的未来发展趋势。     

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。     

乙丙橡胶生产工艺及其技术经济分析

详细论述了乙丙橡胶溶液聚合、悬浮聚和气相聚合生产工艺及特点,进行了初步技术经济评价。通过对各种生产工艺的技术比较,认为溶液聚合工艺作为乙丙橡胶主导生产技术的地位不可动摇,气相聚合工艺将成为今后的发展方向。     

乙丙橡胶的生产与应用

详细论述了乙丙橡胶生产工艺的技术状况及特点 ,认为溶液聚合工艺为目前乙丙橡胶的主要生产技术 ,气相聚合工艺将成为今后发展方向。并介绍了乙丙橡胶在汽车、建筑、电线电缆、聚烯烃类弹性体、聚合物改性等方面的应用     

乙丙橡胶的生产与应用

详细论述了乙丙橡胶生产工艺的技术状况及特点，认为溶液聚合工艺为目前乙丙橡胶的主要生产技术，气相聚合工艺成为今后发展方向。并介绍了乙丙橡胶在汽车、建筑、电线电缆、聚烯烃类弹性体、聚合物改性等方面的应用。     

广东省建设乙丙橡胶装置的必要性和可能性

本文介绍了乙丙橡胶的用途，生产技术路线及生产技术的发展趋势，论述了广东上乙丙橡胶的必要性和可能性。     

三元乙丙橡胶生产技术探讨

介绍了三元乙丙橡胶的用途、生产工艺路线及国内生产能力和技术状况,并对国内的乙丙橡胶工艺技术发展提出了建议意见。     

乙丙橡胶生产技术进展及市场分析

从生产工艺、聚合催化剂和新产品开发等方面概述了乙丙橡胶生产技术的现状及主要进展,讨论了全球乙丙橡胶的技术发展特征,并对国内外市场与消费现状及发展前景进行了分析。     

气相法工艺生产三元乙丙橡胶新技术

介绍了美国联碳公司近年刚刚开发成功的气相法工艺生产三元乙丙橡胶新技术 ,包括气相聚合工艺、气相聚合催化剂以及与传统工艺的对比 ,认为气相法工艺是具有竞争性的新技术。     

原子转移自由基法合成乙丙橡胶接枝物中的热聚合研究

采用原子转移自由基聚合法(ATRP)合成了三元乙丙橡胶与苯乙烯的接枝共聚物(EPDM-g-St),动力学研究表明聚合过程为“活性”聚合。在接枝聚合过程中发现了明显的苯乙烯热聚合现象。对接枝聚合中得到的均聚苯乙烯进行表征的结果表明,苯乙烯在ATRP接枝体系中的热聚合过程在一定程度上受到ATRP机理的控制;升高温度和延长反应时间使得热聚合更为显著。     

动态硫化EPDM/高聚合度PVC热塑性弹性体力学性能的研究

采用动态硫化的方法制备了三元乙丙橡胶（EPDM）/高聚合度聚氯乙烯（HPVC）热塑性弹性体。考察了PVC聚合度、橡塑比、增塑剂添加量、硫化剂用量（质量分数）及不同促进剂配比对体系性能影响,研究了动态硫化工艺条件（硫化时间和硫化温度）对体系性能的影响。实验结果表明：采用动态硫化方法,选用HPVC-2500、橡塑比为30/70、DOP用量为35份、硫化用量为0.4份及合适促进体系,可以制得性能优良的EPDM/HPVC热塑性弹性体,拉伸强度能达到15.18 MPa,断裂伸长率能达到544%。     

乙丙橡胶中试聚合工艺物料平衡关系

乙丙橡胶中试溶液聚合工艺是聚合反应气相与脱气系统气相汇总形成循环物流,循环物流中丙烯的组成是聚合物结构的主导因素,丙烯的相变是聚合反应温度的控制关键,因此,明确聚合、脱气、压缩环节丙烯的含量和状态,是物料衡算、热量衡算、动量衡算的关键因素,更是设备设计、工程控制的决定性因素。本文通过根据乙丙橡胶聚合工艺特点,明确聚合釜气液相乙烯、丙烯的物料分配原则,结合聚合反应热换热关系,通过对丙烯循环量、溶解量的计算,确定了聚合工艺物料状态及衡算关系。     

Investigation of novel polyanilines as new antioxidants for ethylene propylene diene monomer rubber composites

Oxidative aging is a significant deterioration process that affects the performance and durability of rubber materials in various applications. Therefore, this study focuses on the development of new antioxidants-based on polyaniline for ethylene propylene diene monomer (EPDM) rubber to enhance its resistance to oxidative aging. The novel polyanilines were prepared using in situ polymerization method and characterized using Fourier transforms infrared (FTIR) and thermogravimetric analysis (TGA). FTIR illustrates the success synthesis of polyanilines as it shows their characteristic functional groups. The thermal stability of the formed polyanilines is discussed through TGA and derivative of thermogravimetry (DTG) curves. The curves prove the good thermal stability of the synthesized polymers. The prepared polyaniline compounds were mixed to carbon black filled-EPDM rubber composites using a roll mill and then vulcanized using sulfur curing process. Accelerated aging tests for the prepared EPDM rubber composites were conducted to evaluate the effectiveness of the antioxidants. Moreover, their impact on rheometer, mechanical, and swelling properties was studied. The results showed that the EPDM samples with the prepared polyaniline compounds exhibited improved oxidative properties compared to the EPDM sample with commercial antioxidant 2,2,4-trimethyl-1,2-dihydroquinoline. These findings suggest that the novel antioxidants have the potential to enhance the durability and performance of EPDM rubber in various applications.     

Preparation and properties of high‐performance recyclable ethylene propylene diene rubber

To obtain high‐performance recyclable ethylene propylene diene rubber (EPDM), EPDM was chemically functionalized as follows: EPDM was grafted with citraconic acid (CCA) by radical melt polymerization to produce a grafted EPDM (EPDM‐g‐CCA), and EPDM‐g‐CCA was reacted with various amino acids by melt condensation reaction to give amidated copolymers (EPDM‐g‐CCA‐2‐Am, EPDM‐g‐CCA‐7‐Am, and EPDM‐g‐CCA‐12‐Am, where the n indicates the carbon number of amino acid), and then ionomers (EPDM‐g‐CCA/n‐Am/Io) were prepared by melt reaction of EPDM‐g‐CCA/n‐Ams with Zinc oxide (ZnO)/zinc stearate (ZnSt). The mechanical properties/compression set (CS) resistance (elasticity)/recyclability of pristine EPDM, EPDM‐g‐CCA, EPDM‐g‐CCA/n‐Am, and ionomers sheet samples were compared. The tensile strength/modulus, tear strength, and elasticity of samples were mostly increased in the order of ionomers>EPDM‐g‐CCA/n‐Ams>EPDM‐g‐CCA>pristine EPDM. The properties of ionomers increased significantly with increasing the carbon number in amino acid up to seven, and then levelled off or decreased a little. The tensile strength/elasticity (compression set resistance) of recyclable ionomer (EPDM‐g‐CCA/7‐Am/Io) was found to be ～9.42/～2.31 times of pristine EPDM, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42718.     

Graft copolymers from peroxidized EPDM rubber

The transition metal catalyzed peroxidation of the pendant allylic functionality in EPDM rubbers with tertiary butyl hydroperoxide results in elastomeric, high polymer peroxides. The peroxidized EPDM rubbers are useful as free radical initiators for the polymerization and grafting of vinyl monomers in the preparation of comb-type structures. The grafted EPDM rubbers are efficient impact modifiers for thermoplastic resins so long as the polymer grafted onto the EPDM is identical to or is thermodynamically miscible with the composition of said thermoplastic resin.     

Synthesis and photodegradable properties of methyl vinyl ketone–EPDM–styrene graft terpolymer

The graft terpolymerization of methyl vinyl ketone (MVK) and styrene (St) onto ethylene–propylene–diene terpolymer (EPDM) was carried out under various polymerization conditions. The synthesized graft terpolymer, MVK–EPDM–St (MVES), was identified by infrared (IR) spectroscopy. The effects of monomer concentration, mole ratio of MVK to St, reaction time, reaction temperature, and initiator concentration on the graft terpolymerization were examined. Upon UV irradiation in the presence of oxygen, the MVES-containing carbonyl group showed photodegradable properties caused by Norrish type II reaction. The new IR characteristic peaks, such as carbonyl, vinyl, and hydroxy groups of the photodegraded MVES, increased with increasing UV irradiation time. The tensile strength and elongation at break of MVES after UV irradiation were lower than those of before UV irradiation. The color difference of the irradiated MVES was higher than that of EPDM. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1721–1727, 1998     

PS/EPDM blends prepared by in situ polymerization of styrene

PS/EPDM blends formed by in situ polymerization of styrene in the presence of EPDM were prepared. EPDM has excellent resistance to factors such as weather, ozone and oxidation and it could be a good alternative for substituting polybutadiene‐based rubbers in PS toughening. The PS/EPDM blends present two phases, an EPDM elastomeric phase dispersed into a rigid matrix. The blends show higher thermal stability than polystyrene homopolymer due to the stabilizing effect of EPDM incorporation. The mechanical properties of in situ polymerized PS/EPDM blends with different compositions were evaluated before and after accelerated photoaging and compared with the properties of HIPS submitted to the same aging conditions. The blend containing 17 wt % of EPDM presents an increase in the impact resistance of 210% in comparison with the value of PS. Although the initial mechanical properties of HIPS are superior, a pronounced drop was observed after an exposure time. For example, after the aging period, all PS/EPDM blends showed higher strain at break than HIPS. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008