以聚（异戊二烯-苯乙烯）嵌段共聚物为“接枝剂”活性碳正离子聚合制备星形支化丁基橡胶

通过活性负离子聚合制备的聚（异戊二烯-苯乙烯）嵌段共聚物作为“接枝剂”,在2-氯-2,4,4-三甲基戊烷/TiCl4/质子捕捉剂的引发剂体系中,通过活性碳正离子聚合制备了星形支化丁基橡胶。结果表明,聚（异戊二烯-苯乙烯）嵌段共聚物的接枝效果明显,所得聚合物的空间排斥色谱图呈现明显的双峰,相对分子质量分布加宽;     

星形异戊二烯-苯乙烯嵌段共聚物合成方法

中国石油大连润滑油研究开发中心采用阴离子聚合法,以正丁基锂为引发剂,先合成了线形异戊二烯-苯乙烯嵌段活性链;再以二乙烯基苯（DVB）为偶联剂,采用分次滴加法合成了星形异戊二烯-苯乙烯嵌段共聚物。     

用反应挤出法合成苯乙烯-异戊二烯嵌段共聚物

以同向紧密啮合双螺杆挤出机为反应器,有机锂为引发剂,采用混合单体加料方式,本体法一步合成了苯乙烯-异戊二烯嵌段共聚物。核磁共振谱图和透射电子显微照片均表明该共聚物具有纳米级多嵌段结构,其物理机械性能受异戊二烯质量分数的影响。     

苯乙烯-异戊二烯-苯乙烯三嵌段共聚物的环氧化

以甲酸和过氧化氢反应生成的过氧甲酸为氧化剂、聚乙二醇(PEG-400)为相转移催化剂,对苯乙烯-异戊二烯-苯乙烯三嵌段共聚物(SIS)进行了环氧化,考察了SIS的环氧化反应影响因素,并探讨了环氧化反应机理。结果表明,在C=C/甲酸/过氧化氢(摩尔比)为1/2/6、反应时间为2 h、反应温度为50℃、SIS质量分数为20%时,SIS的环氧化效果最好,环氧度可达到39. 2%;加入相转移催化剂PEG-400可以大幅度提高环氧度,当PEG-400/SIS(质量比)为1. 0时,环氧度可达到59. 5%; SIS的环氧化反应主要发生在聚异戊二烯链节中1,4-结构的双键上,且反应活性由强到弱依次为顺式-1,4-结构、反式-1,4-结构、3,4-结构。     

苯乙烯-异戊二烯-苯乙烯嵌段共聚物及其接枝马来酸酐增韧聚苯乙烯/纳米碳酸钙复合材料

以过氧化二异丙苯（DCP）为引发剂,通过单螺杆挤出机熔融挤出,制备了苯乙烯-异戊二烯-苯乙烯接枝马来酸酐（SIS—MAH）,研究了SIS及SIS—MAH对聚苯乙烯（Ps）／纳米碳酸钙（nano—CaCO3）复合材料物理、力学性能的影响,对其结构进行了表征。结果表明,MAH的用量宜为SIS质量分数的3％,DCP的用量应小于MAH质量分数的0．3％;当1份nano—CaCO3加入到PS／SIS（质量比100／2）复合材料3中,SIS与nano—CaCO3产生协同增韧效应,复合材料的无缺口冲击强度可提高到9．83kJ／m^2,但其缺口敏感性增大;SIS—MAH较SIS对PS／nano—CaCO3复合材料具有更好的增韧效果,接枝率为3．08％的SIS—MAH改性PS／CaCO3复合材料（质量比100／5／6）的无缺口冲击强度可提高到11．69kJ／m^2;当SIS用量为6份时,SIS改性复合材料不发生弯曲断裂;当SIS—MAH用量为2份时,SIS—MAH改性复合材料不发生弯曲断裂。     

用原子转移自由基聚合制备苯乙烯／丙烯酸丁酯／苯乙烯三嵌段共聚物

利用原子转移自由基聚合,以α,α′－二氯对二甲苯为双功能引发剂,在ＣｕＣｌ／２,２′－联吡啶配位化合物催化下,采用二段聚合法合成了苯乙烯／丙烯酸丁酯／苯乙烯三嵌段共聚物,用ＧＰＣ测定了嵌段共聚物的相对分子质量及其分布。     

活性正离子聚合向活性自由基聚合转化法合成嵌段共聚物

通过枯基氯／四氯化钛／吡啶／异戊二烯活性正离子聚合反应体系制备了末端是叔氯基的聚异丁烯,经过脱氯化氢反应其分子链末端转化成异丁烯基．在9-硼二环[3,3．1]壬烷、氧气存在下引发苯乙烯的活性自由基聚合,成功地合成了异丁烯-苯乙烯嵌段共聚物,并用核磁共振仪对所得产物进行了表征。     

苯乙烯-异戊二烯-苯乙烯嵌段共聚物的加氢反应及产品性能

采用镍系催化剂催化苯乙烯-异戊二烯-苯乙烯嵌段共聚物（SIS）加氢,对催化反应的机理及催化剂制备进行了研究,确定了催化剂制备及SIS加氢工艺条件,并对产品的结构及性能进行了考察。结果表明,采用异辛酸镍及三异丁基铝作SIS加氢催化剂,当催化剂陈化温度为50~70 ℃、陈化时间大于30 min、镍剂及铝剂质量浓度均为25~40 g/L、铝与镍的摩尔比为3.0~4.0时,催化剂活性较高。当催化剂用量为3×10-4~7×10-4 g/g时,反应1~2 h的SIS中聚异戊二烯段加氢度大于98%,苯环加氢度小于5%。SIS加氢后,力学性能及耐老化性能得到明显改善。     

苯乙烯-异戊二烯-苯乙烯热塑性共聚物产业发展现状与市场

介绍了国内外苯乙烯-异戊二烯-苯乙烯热塑性共聚物(SIS)国内外市场情况。我国曾因SIS主要原料异戊二烯的匮乏,得不到发展,如今我国已掌握C5分离技术,裂解C5资源非常充沛,呼吁加快SIS发展步伐。     

苯乙烯-丁二烯-苯乙烯嵌段共聚物/聚(苯乙烯- 甲基丙烯酸甲酯)热塑性互穿聚合物网络

采用原子转移自由基聚合(ATRP)和分步方法,制备了以苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)为聚合物Ⅰ,聚(苯乙烯-甲基丙烯酸甲酯)[P(St—MMA)]为聚合物Ⅱ的SBS／P(St—MMA)热塑性互穿聚合物网络(TIPN)。研究了P(St—MMA)质量分数、MMA／St(摩尔比)和不同聚合方式对TIPN动态力学性能和黏结性能的影响。结果表明,采用ATRP法制备的TIPN的动态力学性能和黏结性能均优于常规自由基聚合制备的TIPN。高温区聚苯乙烯(PSt)嵌段的玻璃化转变温度明显降低,而损耗角正切tanδ2显著增加;TIPN的黏结性能也得到明显改善,拉伸剪切强度提高了3倍多。     

用磺酰氯作氯化剂合成氯化丁基橡胶

以磺酰氯作氯化剂、烃类油作溶剂,采用溶液法制备了氯化丁基橡胶,对反应产物的结构进行了表征,考察了氯化反应温度、反应时间和磺酰氯用量对氯化丁基橡胶氯含量及数均分子量的影响.结果表明,所得产物的结构与工业生产的产品基本相同;在反应温度为120～140℃、反应时间约为6 min、磺酰氯用量为0.6～1.8 mL时,可制备出含...     

Synthesis of well-defined star-branched polymers by stepwise iterative methodology using living anionic polymerization

This article reviews the synthesis of regular and asymmetric star-branched polymers with well-defined structures by methodologies using living anionic polymerization, especially focusing on the synthetic approaches accessible for precisely controlled architectures of star-branched polymers concerning molecular weight, molecular weight distribution, arm number, and composition. The reason for selecting living anionic polymerization from many living/controlled polymerization systems so far developed is that this living polymerization system is still the best to meet the strict requirements for the precise structures of star-branched polymers. Furthermore, we herein mainly introduce a novel and quite versatile stepwise iterative methodology recently developed by our group for the successive synthesis of many-armed and multi-compositional asymmetric star-branched polymers. The methodology basically involves only two sets of the reaction conditions for the entire iterative synthetic sequence. The reaction sequence can be, in principle, limitlessly iterated to introduce a definite number of the same or different polymer segments at each stage of the iteration. As a result, a wide variety of many-armed and multi-compositional asymmetric star-branched polymers can be synthesized.     

以乙基二氯化铝和水为引发体系合成溶液法丁基橡胶

以乙基二氯化铝和水为引发体系,己烷和氯甲烷为溶剂,在-80 ℃下通过溶液法合成了丁基橡胶,研究了引发体系在不同陈化时间下的红外光谱特征,考察了引发剂和单体用量对丁基橡胶相对分子质量及其分布、不饱和度及单体转化率的影响.结果表明,引发体系活性中心的红外特征峰在580 cm-1和610 cm-1处,并随着陈化时间的延长,5...     

4-氨基脲嘧啶与溴化丁基橡胶反应制备热可逆交联丁基橡胶

在相转移催化剂作用下,用4-氨基脲嘧啶与溴化丁基橡胶(BBR)反应制备了热可逆交联丁基橡胶(IIR),考察了取代反应的影响因素,并研究了含有4-氨基脲嘧啶基团的IIR的结构与拉伸性能.结果表明,4-氨基脲嘧啶取代了BBR中的溴原子,且伯溴代烯丙基结构中的溴原子被完全取代,仲溴代烯丙基结构中的溴原子大部分被取代;IIR上的4-氨基脲嘧啶基团可通过氢键自组装形成热可逆网络结构;在4-氨基脲嘧啶用量为0.010 mol、相转移催化剂四丁基溴化胺/4-氨基脲嘧啶(摩尔比)为1:1、氢氧化钾水溶液/甲苯溶液(体积比)为50:80、反应温度为80 ℃、反应时间为4 h的条件下,4-氨基脲嘧啶与BBR反应后溴原子取代率最大值可达到77%;含有4-氨基脲嘧啶基团的IIR的拉伸强度较BBR增大了2倍,具有热塑性弹性体特征.     

Synthesis of hydroxy-functionalized star-branched PMMA by anionic polymerization

Living anionic polymerization has been exploited to synthesize hydroxy end-functionalized PMMA star-branched polymers. Protected hydroxy-functionalized alkyl lithium initiators have been used to initiate anionic polymerization of MMA. Subsequently the living chains with protected hydroxyl function have been used to cross-link ethylene glycol dimethacrylate (EGDMA) in order to form star-branched polymers with cross-linked EGDMA core via ‘arm-first’ method. The linear arms and the star molecules have been characterized by ¹HNMR, GPC, and light scattering. Variation in the number of arms with arm molecular weight and cross-linker loading has been studied. Star-branched PMMA-OH with as many as ~10 arms could be successfully made. Increased molecular weight of PMMA-OH led to decrease in the number of arms incorporated due to increased steric hindrance on the core. Increase in EGDMA concentration slightly increased the arm incorporation.     

溴化丁基橡胶的热可逆共价交联

利用季铵化反应的热可逆特性,采用含有叔胺官能团的聚合物替代传统交联剂,研究了溴化丁基橡胶(BIIR)的交联反应活性及交联的热可逆性.结果表明,硫化温度和硫化时间对交联BIIR的凝胶含量有显著影响,在160 ℃×30 min的硫化条件下,交联剂呈现出较高的交联活性;不同温度下的转矩测定和190 ℃二次热压的塑性流动证实交联BIIR具备热塑加工性.     

Macromers by carbocationic polymerization

Summary This communication describes the synthesis of two novel CH₂=CH-O-headed polyisobutylene (PIB)-based macromers: and The syntheses were worked out by the help of model experiments and subsequently implemented on polymers. The structures were established by detailed¹H and¹³C NMR spectroscopies.See J. P. Kennedy, S. Midha, A. Gadkari: J. Macromol. Sci. Chem., in press, for paper X in this series     

Macromers by carbocationic polymerization

Summary The validity of the copolymer composition equation for the copolymerization of macromers with small monomers for the preparation of graft copolymers has been examined. The reactivity ratios of high molecular weight macromers r₁ cannot be determined experimentally with sufficient accuracy whereas those of small monomers r₂ may be calculated by r₂=ln(1-p₂)/ ln(1-p₁), where p₁ and p₂ are the respective conversions of the macromer and small monomer. A single experimental datum obtained even at high conversions may be used. The error of the method can be readily calculated.     

Macromers by carbocationic polymerization

Polymer Bulletin - Copolymerization of α-(p-vinylphenyl) polyisobutylene(p-polyisobutenylstyrene, PIB-St) with styrene (St) in emulsion has been investigated. Copolymerization occurs only when...     

用聚合转化法合成聚异丁烯-聚丙烯酸叔丁酯嵌段聚合物

使用BCl3/CH2Cl2/DTBP/IB反应体系实现了异丁烯的正离子聚合,得到末端为硼氧烷基的聚异丁烯,其与苯基溴化镁发生金属转移反应,生成末端为二苯基硼烷的聚异丁烯,其在常温下与氧气发生氧化反应,生成碳氧自由基,从而引发丙烯酸叔丁酯的自由基聚合,得到异丁烯和丙烯酸叔丁酯的嵌段聚合物.