用负离子原位聚合法合成链端氨基官能化集成橡胶

大连理工大学研究人员采用负离子原位聚合法,以N,N-二甲氨基苯甲醛缩苯胺为封端剂合成了链端氨基官能化集成橡胶,考察了封端剂用量、聚合物相对分子质量及大分子链活性端种类对分子官能化封端率的影响,并对聚合物进行了表征和性能测试。结果表明,N,N-二甲氨基苯甲醛缩苯胺封端剂可以与大分子活性端等摩尔反应,     

用负离子原位聚合法合成链端氨基官能化集成橡胶

普利司通开发成功新型轮胎印刷技术     

双硅氧烷端基溶聚丁苯橡胶的合成

采用负离子聚合方法,以环己烷-己烷为溶剂、四氢呋喃为结构调解剂、双锂为引发剂进行丁二烯-苯乙烯共聚,聚合结束后加入r-氯丙基三甲氧基硅烷进行封端,得到双硅氧烷端基的溶聚丁苯橡胶(SSBR),并用核磁共振对其进行了表征.结果表明,所合成的产物为双硅氧烷端基SSBR;并通过核磁共振谱图计算了不同相对分子质量的SSBR的封端效率.     

含双官能团封端剂的合成及在负离子法制备端基官能化聚苯乙烯中的应用

设计合成了一种含有胺基和烷氧基硅烷基双官能团的封端剂——N-对二甲氨基苯亚甲基-3-三乙氧基硅烷基-1-丙胺(DTEOS),并将其用于通过活性负离子聚合技术制备端基官能化聚苯乙烯(PS-DTEOS)中。采用傅里叶变换红外光谱和核磁共振波谱对DTEOS和PS-DTEOS的微观结构进行了表征,并用凝胶渗透色谱法测定了它们的相对分子质量及其分布。研究了DTEOS与聚苯乙烯基锂的定量反应关系,以及DTEOS加入量、封端反应温度、封端反应时间和聚苯乙烯的相对分子质量对封端效率的影响。结果表明,封端反应在10~20 min内快速完成,且没有副反应发生;封端反应温度在50~80℃和聚苯乙烯的数均分子量在5 000~50 000内变化时对封端效率的影响不大;封端剂可与聚苯乙烯基锂进行等摩尔封端反应,封端效率在80%以上,实现了用封端反应制备官能化聚苯乙烯的预期设想。     

烯烃复分解法制备端基官能化液体橡胶研究进展

用烯烃复分解法制备端基官能化液体橡胶具有分子量可控、易于引入多种官能团、反应条件较温和等优势。本文即综述了利用烯烃复分解法制备端羟基、端羧基、端酯基等官能化液体橡胶的研究新进展,并提示了其今后的发展方向。     

负离子封端法合成端基官能化SBS及其动态力学性能分析

采用自制的1,5-二氮二环[3．1．0]己烷为负离子聚合封端试剂,制备了不同相对分子质量的聚苯乙烯模型聚合物。结果表明,该封端试剂能定量地与聚苯乙烯活性种反应。末端氨基官能化苯乙烯-丁二烯-苯乙烯三嵌段共聚物末端接上极性基团后,产物的储存模量和损耗模量均上升;聚苯乙烯微区的损耗因子增加,而聚丁二烯微区的损耗因子下降。     

官能化溶聚丁苯橡胶研究进展

介绍了溶聚丁苯橡胶的发展历程,从官能化引发剂、官能化封端改性等方面详述了官能化溶聚丁苯橡胶的研究进展及溶聚丁苯橡胶的官能化技术在轮胎用橡胶方面的重要作用。将官能化技术和偶联技术结合而产生的官能化星型溶聚丁苯橡胶是丁苯橡胶研究的一个重要方面。     

氮官能化多锂引发丁二烯/异戊二烯/苯乙烯聚合动力学

以自制氮官能化多锂(以下简称Li)为引发剂,N,N,N′,N′-四甲基乙二胺(TMEDA)为极性调节剂,环己烷为溶剂,对苯乙烯(St)、异戊二烯(Ip)、丁二烯(Bd)进行负离子聚合,合成了星形集成橡胶丁二烯-异戊二烯-苯乙烯三元共聚物(SIBR),研究了不同TMEDA/Li(摩尔比)下SIBR的聚合反应动力学。结果表明,在三元共聚合反应中,3种单体的反应速率与其各自浓度均符合一级动力学关系;在SIBR的合成体系中,随着TMEDA/Li的增大,Bd的反应速率常数先升高后降低,St的反应速率常数逐渐增加,Ip的反应速率常数逐渐降低;当TMEDA/Li为1·0、二乙烯基苯(DVB)/Li(摩尔比)为0·8、引发剂浓度为7·69×10-4mol/L时,单体Bd,Ip,St的表观增长反应活化能分别为31·59,47·64,31·76kJ/mol,链增长频率因子分别为1·02×104,1·09×106,5·27×103min-1。     

二甲氨基链中多官能化溶聚丁苯橡胶的合成

采用负离子溶液聚合法,以仲丁基锂为引发剂、环己烷为溶剂、四氢呋喃为结构调节剂,以及1,1-双（4-二甲基氨基苯基）乙烯为官能化共聚单体与丁二烯和苯乙烯进行活性负离子共聚合,制备了二甲氨基链中多官能化丁二烯-苯乙烯共聚物,考察了聚合温度和结构调节剂用量对聚合动力学和聚合物微观结构的影响。结果表明,共聚物链中二甲氨基官能团数量可通过调整聚合温度和结构调节剂用量进行准确控制,随聚合温度升高和四氢呋喃用量的增加,单体的总反应速率和转化率都逐渐增大;聚合物中1,2-结构的含量随结构调节剂用量的增加而逐渐增大,随聚合温度升高而逐渐减小。求得聚合温度为50 ℃时丁二烯和苯乙烯单体的平均竞聚率为69.67。     

负离子聚合法合成笼型聚倍半硅氧烷双端基官能化聚苯乙烯及其表征

采用氯丙基七异丁基多面体低聚倍半硅氧烷为封端剂,通过负离子聚合法合成了笼型聚倍半硅氧烷(POSS)双端基官能化聚苯乙烯(POSS-PS-POSS)。采用核磁共振波谱和液相凝胶渗透色谱对POSS-PS-POSS的结构和相对分子质量及其分布进行了表征,证明了POSS与聚苯环乙烯基锂发生了封端反应生成POSS-PS-POSS。同时考察了调节剂和封端剂的用量、封端温度和时间、聚苯乙烯的数均分子量对封端效率的影响。结果表明,当四氢呋喃与双丁基锂的摩尔比为5.0/1.0、封端剂与双丁基锂的摩尔比为1.1/1.0、反应温度为60℃、反应时间为50 min时,封端效率最高。     

Synthesis of tetramethyl-p-silphenylenesiloxanedimethylsiloxane triblock copolymer by employing living anionic polymerization

Dimethylsiloxane-tetramethyl-p-silphenylenesiloxane-dimethylsiloxane (DMS-TMPS-DMS) triblock copolymer was synthesized by employing living anionic polymerization of hexamethylcyclotrisiloxane (D₃). Two synthetic methods were carried out for the polymerization. One of those methods was the anionic polymerization of D₃ initiated at the silanolate anion which was prepared from the terminal hydroxyl group of silanol-terminated TMPS prepolymer by reaction with n-butyllithium (method 1). The other was the coupling reaction of vinyl-terminated TMPS prepolymer with hydrosilyl-terminated DMS prepolymer obtained from the anionic polymerization of D₃ by using diphenylmethylsilanolate anion as initiator (method 2). In method 1, DMS contents of the copolymers ranged from 25.8 to 72.5 wt% and the values agreed with the ratio of D₃ to TMPS prepolymer. The weight-average molecular weights ranged from 1.36×10⁴ to 19.4×10⁴ and were close to the predicted values calculated from the $\text{M}\text{?}{}_{\mathrm{v}}$ of the TMPS prepolymer and the amount of D₃ added. In the case of method 2, weight-average molecular weights ranged from 19.5×10⁴ to 24.2×10⁴. The high molecular weight copolymer could thus be obtained by method 2. Intrinsic viscosity values of the triblock copolymers agreed with calculated values obtained by considering the copolymer as a binary mixture of these homopolymers. Differential scanning calorimetry and thermogravimetry were carried out on the triblock copolymers. The equilibrium melting temperatures of each of the copolymers were very close to that of poly-TMPS (160°C). The glass transition temperature and heat of fusion were decreased as the DMS content was increased. The thermogravimetric curves for the copolymers indicated that the thermal stability of the triblock copolymer was intermediate between the DMS and TMPS homopolymers.     

Synthesis of asymmetric H-shaped block copolymer by the combination of atom transfer radical polymerization and living anionic polymerization

A new asymmetric H-shaped block copolymer (PS)₂-PEO-(PMMA)₂ has been designed and successfully synthesized by the combination of atom transfer radical polymerization and living anionic polymerization. The synthesized 2,2-dichloro acetate-ethylene glycol (DCAG) was used to initiate the polymerization of styrene by ATRP to yield a symmetric homopolymer (Cl-PS)₂-CHCOOCH₂CH₂OH with an active hydroxyl group. The chlorine was removed to yield the (PS)₂-CHCOOCH₂CH₂OH ((PS)₂-OH). The hydroxyl group of the (PS)₂-OH, which is an active species of the living anionic polymerization, was used to initiate ethylene oxide by living anionic polymerization via DPMK to yield (PS)₂-PEO-OH. The (PS)₂-PEO-OH was reacted with the 2,2-dichloro acetyl chloride to yield (PS)₂-PEO-OCCHCl₂ ((PS)₂-PEO-DCA). The asymmetric H-shaped block polymer (PS)₂-PEO-(PMMA)₂ was prepared via ATRP of MMA at 130 °C using (PS)₂-PEO-DCA as initiator and CuCl/bPy as the catalyst system. The architectures of the asymmetric H-shaped block copolymers, (PS)₂-PEO-(PMMA)₂, were confirmed by ¹H NMR, GPC and FT-IR.     

负离子聚合法合成丁二烯-异戊二烯无规共聚物的序列结构

以正丁基锂(n-BuLi)为引发剂、十二烷基苯磺酸钠(SDBS)为调节剂,在环己烷中对丁二烯(Bd)和异戊二烯(Ip)进行负离子聚合制得Bd-Ip共聚物,考察了反应温度、单体配比及调节体系对Ip共聚活性及共聚物序列分布的影响。结果表明,提高反应温度或增加Ip单体含量、SDBS/n-BuLi(摩尔比)由0/1.0增大到0.5/1.0,均可提高Ip共聚活性;共聚物序列分布服从一级Markov统计模型,在70℃、Ip/Bd(质量比)5/5、SDBS/n-BuLi(摩尔比)0.5/1.0、单体质量浓度0.12 g/mL的条件下,在共聚物中Ip、Bd 2种单元的同等长度单元组浓度趋于一致,所得共聚物的无规化程度高。     

Synthesis of symmetric H-shaped block copolymer by the combination of ATRP and living anionic polymerization

A novel fluorescent dye labeled H-shaped block copolymer, (PMMA-Fluor-PS)₂-PEO-(PS-Fluor-PMMA)₂, is synthesized by the combination of atom transfer radical polymerization (ATRP) and anionic polymerization (AP). To obtain the designated structure of the copolymer, a macroinitiator, 2,2-dichloro acetyl-PEO-2,2-dichloro acetyl (DCA-PEO-DCA), was prepared from DCAC and poly(ethylene oxide). The copolymer was characterized by ¹H NMR, GPC and fluorescence spectroscopy.     

One-pot synthesis of primary amino end-functionalized polymers by reaction of living anionic polybutadienes with nitriles

We present a convenient method to synthesize polymers with primary amino groups by end-capping of living anionic chain ends with nitriles followed by reduction in a one-pot process. As an example, the addition of pivalonitrile to the chain ends of oligobutadienyllithium in toluene, followed by the reduction with sodium borohydride quantitatively leads to ω-amino-oligo-1,4-butadiene, as demonstrated by ¹H and ¹³C NMR, thin-layer chromatography and MALDI-ToF mass spectrometry.     

Synthesis of end-functionalized polymer by means of living anionic polymerization. 4. Synthesis of polyisoprene and polystyrene with epoxy termini by reaction of their anionic living polymers with 2-bromoethyloxirane

In order to synthesize ω-epoxy-functionalized 1,4-polyisoprene ω-epoxy- and α,ω-diepoxy-functionalized polystyrenes, anionic living polyisoprene and polystyrene were allowed to react with excess amounts of 2-bromoethyloxirane in THF at ?78°C. The resulting polymers were analysed by SEC, ¹H and ¹³C NMR spectroscopy, and thin layer chromatography with flame ionization detection (TLC–FID). Both mono- and di-epoxy terminated polymers of controlled molecular weights (2.5 × 10³?2.6 × 10⁴ g/mol) and of narrow molecular weight distributions were obtained quantitatively with high functionalities.     

采用负离子原位聚合法制备聚丁二烯/二氧化硅纳米复合材料

采用负离子原位聚合工艺制备了聚丁二烯(PB) /SiO2纳米复合材料,研究了复合材料的结构及性能。结果表明,经过γ-(甲基丙烯酰氧基)丙基三甲氧基硅烷(MPS)处理后的SiO2粒子与PB基体形成了强烈的界面相互作用,使得复合材料的玻璃化转变温度(Tg)升高,热稳定性提高,储能模量(E′)明显增大,损耗因子(tanδ)降低。     

阴离子聚丙烯酸胺的合成

采用氧化一还原引发体系,以丙烯酞胺、丙烯酸为单体,通过水溶液聚合合成了高分子量的阴离子型聚丙烯酞胺.研究了EDTA用量、反应时间、pH值和AA/AM配比等对聚丙烯酞胺分子量、聚合转化率以及溶解性能的影响.     

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.