茂金属间规聚苯乙烯

论述了茂金属催化体系，影响聚合和聚合物性能的主要因素，聚合反应釜以及间规聚苯乙烯的性能，加工及应用。     

茂金属催化苯乙烯苯体间规聚合

采用新型茂金属催化剂体系进行苯乙烯本体间规聚合。研究了催化剂浓度,聚合温度和时间对聚合速率,聚合物分子量和颗粒形态的影响,成功地制得了高转化率下外观满意的粉体间规聚苯乙烯,避免了聚合过程中的凝胶或结块。     

茂金属催化苯乙烯本体间规聚合

采用新型茂金属催化剂体系（ Ｃｐ Ｔｉ（ Ｒ Ｏ Ｐｈ Ｏ）３／ Ｍ Ａ Ｏ／ Ｔ Ｉ Ｂ Ａ）进行苯乙烯（ Ｓｔ）本体间规聚合。研究了催化剂浓度、聚合温度和时间对聚合速率、聚合物分子量和颗粒形态的影响,成功地制得了高转化率下外观满意的粉体间规聚苯乙烯（ｓ Ｐ Ｓ）,避免了聚合过程中的凝胶或结块。发现茂金属催化的 Ｓｔ 间规聚合不具有活性聚合的特征,颗粒状的 ｓ Ｐ Ｓ具有 δ晶型结构,而凝胶状的 ｓ Ｐ Ｓ几乎未发生结晶。     

一种新型聚苯乙烯--结晶聚苯乙烯

DOW化学公司最近推出了一种新型聚苯乙烯树脂——间规聚苯乙烯 (syndiotacticpolystyrene,SPS) ,是一种结晶性的工程塑料。SPS与传统聚苯乙烯在聚合方法、化学性质及耐热性质上是完全不同的 ,它是利用茂金属作为催化剂 ,将聚苯乙烯单体定向聚合制得的一种具有间规结构的聚苯乙烯 ,即相邻苯环在聚苯乙烯链上以接近 12 0度规则排列。这种间规聚苯乙烯具有快速结晶性 ,在一般注塑条件下 ,可达到几乎完全的结晶结构。SPS结晶聚苯乙烯熔点为 2 70℃ ,玻璃化转变温度为 98℃ ,加入玻璃纤维增强后的 SPS热变形温度可达 2 5 0℃ ,而传统聚苯乙…     

“新型茂钛间规聚苯乙烯催化剂的研究”专题在京通过鉴定验收

由上海石油化工研究院和中山大学共同承担的国家“九五”重点科技攻关项目“新型茂钛间规聚苯乙烯催化剂的研究”专题于2000年8月14日在京通过了中国石油化工集团公司组织的专家鉴定验收。该专题进行了高效新型茂钛间规聚苯乙烯催化剂的研制。苯乙烯间规聚合工艺和聚合反应工程的研究,在适当     

茂金属催化剂及其聚烯烃的开发

报导了中国石油化工总公司石油化工科学研究院近两年茂金属催化剂及其催化烯烃聚合技术的研究进展，间规选择性复合型茂金属论剂技术已开发成功；用基催化珙烯聚合，在国内首次得到合格的商业用间规聚丙烯；完成了限制几何构型复合型茂金属的合成探索，获得具有较好活性的系列催化剂。实现了茂金属催化剂的负载化为茂金属催化剂在相烯烃聚合工艺中的应用奠定了基础。     

间规聚苯乙烯的合成与工业化研究

本文评述了间规聚苯乙烯（ｓＰＳ）的联合机理与工业化研究，介绍了茂金属催化剂和聚合反应器。强调要实现ｓＰＳ的工业化，尚需加强以聚合反应工艺和反应器开发为目标的聚合反应工程研究。     

间规聚苯乙烯催化剂研究进展

间规聚苯乙烯是一种高熔点的高分子材料,具有多方面优异特性,在多个领域有广泛的应用前景。综述用于苯乙烯间规聚合的单中心过渡金属催化剂的研究进展,总结各类催化剂用于聚合的特点。简单的单茂钛催化剂(Cp’Ti X3)是最早用于有效催化苯乙烯间规聚合的催化剂,但活性和间规聚合物含量都有待提高;结构如Cp’Ti Xn L的单茂钛催化剂,通过引进非茂给电子配体,可以大大提高聚合活性,提高间规聚合物比例,某些催化剂还可以实现活性聚合;ⅢB过渡金属(钪和稀土元素)化合物作为间规聚苯乙烯聚合催化剂的研究,有助于理解苯乙烯间规聚合,乃至烯烃配位聚合机理。对间规聚苯乙烯催化剂工业现状和研发需求进行分析。     

茂金属催化剂及烯烃高分子材料研究新进展

介绍茂金属催化剂的一般组成、主要特性及在烯烃聚合催化技术所具有的显著优势和近年研究取得的一些新进展。详细叙述采用茂金属催化工艺技术合成的一些烯烃聚合物,如聚乙烯(PE)、聚丙烯(PP)、间规聚苯乙烯(sPS)、茂金属环烯烃、茂金属乙丙橡胶、茂金属乙烯-辛烯共聚物等。这些茂金属聚合物与传统催化剂合成的聚合物相比,具有更优良的特性和更广阔的应用范围。许多用传统催化剂难以合成的材料,在采用茂金属催化技术后变得容易进行。在烯烃聚合物合成中茂金属催化剂正在替代传统催化剂。茂金属催化剂在全球增长非常迅速,具有广阔的应用和市场前景。     

均相茂金属催化剂催化苯乙烯间规聚合中搅拌的作用

在不同搅拌型式的聚合反应器中使用均相茂金属催化剂（Cp^*Ti(OR)3/MAO/TIBA催化苯乙烯本体间规聚合。研究搅拌桨型式、反应器以及搅拌速度对聚合物形态以及聚合过程的影响,并分析了搅拌、结晶和聚合之间的关系。研究表明,良好的搅拌剪切对避免凝胶、促进粉状间规聚苯乙烯的生成至关重要。聚合动力学的研究表明,搅拌转速不仅能影响聚合物的颗粒形状,也能通过改变聚合物原生晶的结晶速率从而影响聚合速率。     

合成间同立构PS用单中心催化剂的研究进展

综述了茂金属催化剂和非茂钛催化剂合成间同立构聚苯乙烯的研究进展,其中,茂金属催化剂主要包括茂钛催化剂、单茂钛催化剂、茚钛催化剂、双核金属催化剂及负载型催化剂等。今后的研究重点是负载型茂金属催化剂和非茂钛催化剂,单中心催化剂将对合成间同立构聚苯乙烯的工业化发展发挥重要的作用。     

Synthesis and characterization of graft copolymers of syndiotactic polystyrene with polybutadiene and 4‐methylstyrene

The basic method for synthesizing syndiotactic polystyrene‐g‐polybutadiene graft copolymers was investigated. First, the syndiotactic polystyrene copolymer, poly(styrene‐co‐4‐methylstyrene), was prepared by the copolymerization of styrene and 4‐methylstyrene monomer with a trichloro(pentamethyl cyclopentadienyl) titanium(IV)/modified methylaluminoxane system as a metallocene catalyst at 50°C. Then, the polymerization proceeded in an argon atmosphere at the ambient pressure, and after purification by extraction, the copolymer structure was confirmed with ¹H‐NMR. Lastly, the copolymer was grafted with polybutadiene (a ready‐made commercialized unsaturated elastomer) by anionic grafting reactions with a metallation reagent. In this step, poly(styrene‐co‐4‐methylstyrene) was deprotonated at the methyl group of 4‐methylstyrene by butyl lithium and further reacted with polybutadiene to graft polybutadiene onto the deprotonated methyl of the poly(styrene‐co‐4‐methylstyrene) backbone. After purification of the graft copolymer by Soxhlet extraction, the grafting reaction copolymer structure was confirmed with ¹H‐NMR. These graft copolymers showed high melting temperatures (240–250°C) and were different from normal anionic styrene–butadiene copolymers because of the presence of crystalline syndiotactic polystyrene segments. Usually, highly syndiotactic polystyrene has a glass‐transition temperature of 100°C and behaves like a glassy polymer (possessing brittle mechanical properties) at room temperature. Thus, the graft copolymer can be used as a compatibilizer in syndiotactic polystyrene blends to modify the mechanical properties to compensate for the glassy properties of pure syndiotactic polystyrene at room temperature. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

茂钛催化剂合成及苯乙烯间规聚合

介绍了茂钛催化剂ＣｐＴｉ（ＯＰｈ）３（Ｃｐ为环戊二烯基）的合成。使用ＣｐＴｉ（ＯＰｈ）３／ＭＡＯ均相催化体系,研究了工艺条件对苯乙烯间规聚合的影响。初步探讨了以带有反应性功能基团的聚苯乙烯为载体,负载ＣｐＴｉＣｌ３后进行的苯乙烯间规聚合。同时采用了不同配体的ＣｐＴｉ（ＯＲ）３催化剂用于苯乙与乙烯或丙烯共聚合,得到的共聚产物是一类应用前景良好的工程塑料。     

Copolymerization of styrene by diphenylzinc-additive systems. Part II: Copolymerization of styrene/1-alkene by Ph2Zn-metallocene-MAO systems

Summary The copolymerization of styrene with 1-alkene (1-hexene, 1-decene and 1-hexadecene) has been tested using combined diphenylzinc-additive initiator systems, including diphenylzinc (Ph₂Zn), a metallocene and methylaluminoxane (MAO). The metallocene were biscyclopentadienyltitanium dichloride, bis(n-butylcyclopentadienyl)titanium dichloride, cyclopentadienyltitanium trichloride and bisindenylzirconium dichloride. For Ph₂Zn-metallocene-MAO systems, titanocenes gave mainly syndiotactic homo polystyrene irrespective of the styrene/1-alkene proportion in the initial feed. Systems including Ind₂ZrCl₂ were able to copolymerize styrene 1-alkene with the copolymers incorporating alkene in a lower proportion than the present in the initial feed. Keywords: Styrene copolymerization; diphenylzinc; metallocene catalysts; tacticity. Received: 17 November 2000/Revised version: 9 May 2001/Accepted: 10 May 2001     

Pressure effects on polymerization of syndiotactic polystyrene

Polymerization pressure has a direct effect on the synthesis of syndiotactic polystyrene (s-PS) with metallocene as a catalyst. The polymerization rate, yield rate, and average molecular weight show a linear relationship with pressure, that is, they all increase with increased polymerization pressure. However, under 1000 psi, the yield of s-PS increases with polymerization duration while the yield rate decreases. As a whole, this syndiotactic polymerization proceeds relatively fast in comparison with ordinary vinyl polymerization. Optimal conditions (pressure, temperature, and duration) for the synthesis of s-PS have been explored. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1747–1752, 1998     

Synthesis and characterization of functionalized syndiotactic polystyrene copolymers

Functionalized syndiotactic polystyrene copolymers were synthesized and characterized. The syndiotactic polystyrene copolymers, poly(styrene‐co‐4‐methylstyrene) (sPSMS), were prepared by styrene with 4‐methylstyrene with a metallocene/methylaluminoxane catalyst. In addition, grafted copolymers, chemically grafted with isoprene onto an sPSMS backbone [poly(styrene‐co‐4‐methylstyrene)‐g‐polyisoprene (sPSMS‐g‐PIP)] were synthesized by anionic grafting polymerization with a metallation reagent. In this study, we also examined the effect of the degree of functionalization (epoxidation) on the polymer structure of the sPSMS‐g‐PIP copolymers. Experimental results indicate that the crystallinity of the sPSMS‐g‐PIP copolymer was lower than that of the ungrafted sPSMS copolymer. Moreover, the epoxy‐containing sPSMS‐g‐PIP copolymer effectively increased the thermal stability more than did the sPSMS‐g‐PIP copolymer alone. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1038–1045, 2002     

间规聚苯乙烯共混改性研究进展

介绍了间规聚苯乙烯(SPS)的特点，论述了间规聚苯乙烯共混改性的研究进展。详细介绍了SPS和聚苯醚共混，SPS和弹性体共混以及SPS和聚酰胺、聚酯等高聚物的共混改性，并展望了SPS的应用前景。     

Selective separation of water from aqueous alcohol mixtures through functionalized syndiotactic poly(styrene‐co‐4‐methylstyrene) membranes by pervaporation

The pervaporation performances of a series of functionalized syndiotactic poly(styrene‐co‐4‐methylstyrene) (SPSM) membranes for various alcohol mixtures were investigated. The syndiotactic polystyrene copolymers, poly(styrene‐co‐4‐methylstyrene) (SPSM), were prepared by styrene with 4‐methylstyrene using a Cp*Ti(OCH₃)₃/methyl aluminoxane (metallocene/MAO) catalyst. The effect of functionalization on the thermal properties and polymer structure of the SPSM membranes were also investigated. The crystallinity of the functionalized SPSM membrane is lower than that of the unfunctionalized SPSM membranes. The water molecules preferentially permeate through the SPSM membranes. Compared with unfunctionalized SPSM membranes, the functionalized SPSM membrane effectively increases the membrane formation performances and the pervaporation performances. The optimun pervaporation performance (a separation factor of 510 and permeation rate of 220 g/m²h) was obtained by the bromination of SPSM (SPSMBr) membrane with a 90 wt % aqueous ethanol solution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2247–2254, 2002