The scientific and technical history of polymerization can be divided into three periods, which will be illustratedfor emulsion polymerization. The first period was when emulsion polymers were originally produced, and...The scientific and technical history of polymerization can be divided into three periods, which will be illustratedfor emulsion polymerization. The first period was when emulsion polymers were originally produced, and was developed asan attempt to copy natural rubber latex. Indeed, the natural process is quite different from the synthetic process of emulsionpolymerization, which in fact does not even need an emulsion to be present: the term is a misnomer! The results werefunctional but limited. In the second period, the first theories appeared, and a huge range of products was madefor surface coatings, adhesives, commodity polymers such as SBR, neoprene, etc. The work of the outstanding pioneers wasbased on limited types of experimental data, and some suppositions are now seen to be incorrect. Nevertheless, manyexcellent products were made and have evolved to many materials currently in everyday use. The third period of emulsionpolymerization is now dawning. The scientific efforts of many teams over previous decades, aided by the advent of newphysical techniques for investigation, have resulted in better understanding of the fundamentals of emulsion polymerizations.Some examples from the author's group involve creating novel materials using controlled seeded emulsion polymerizationfrom natural rubber latex and other polyenes. Latex topology and controlled free-radical chemistry can be combined toproduce a) a comb polymer with hydrophobic backbone and hydrophilic 'teeth', or b) with sufficient in situ compatibilizerbetween two otherwise incompatible polymers to yield a spatially uniform material down to the nanostructure level, and c) toproduce controlled nanostructures.展开更多
A novel multifunctional macromolecular organolithium initiator （PD-Sn-（RLi）3） was prepared via living anionic polymerization and used for the synthesis of miktoarm star copolymers in cyclohexane. The average molec...A novel multifunctional macromolecular organolithium initiator （PD-Sn-（RLi）3） was prepared via living anionic polymerization and used for the synthesis of miktoarm star copolymers in cyclohexane. The average molecular weight, polydispersity index, microstructure and unit composition of the miktoarm star copolymers were characterized with GPC and 1H-NMR. Performances of the miktoarm star styrene-butadiene rubbers were investigated in comparison with those of the blend rubbers such as the tin-coupled star-shaped random copolymers of styrene-butadiene rubber（S-SBR）/natural rubber （NR） blend rubber and S-SBR/Cis-1, 4-polybutadiene rubber （Cis-BR） blend rubber.展开更多
以吉林石化公司有机合成厂的乳聚丁苯橡胶(SBR)生产配方为标准配方,研究了聚合反应时间对转化率的影响,分析了提高转化率对SBR的生胶门尼黏度、结合苯乙烯含量、凝胶含量、相对分子质量及其分布、胶乳黏度等基本性能的影响。结果表明,...以吉林石化公司有机合成厂的乳聚丁苯橡胶(SBR)生产配方为标准配方,研究了聚合反应时间对转化率的影响,分析了提高转化率对SBR的生胶门尼黏度、结合苯乙烯含量、凝胶含量、相对分子质量及其分布、胶乳黏度等基本性能的影响。结果表明,在标准配方条件下,延长聚合反应时间,转化率可以达到70%。转化率为70%时所得SBR与转化率为62%时所得SBR相比,前者的生胶凝胶含量和胶乳黏度均增大了1倍,数均相对分子质量、重均相对分子质量和Z均相对分子质量均高于后者,相对分子质量分布变宽,且前者的生胶结合苯乙烯含量能够达到产品标准,而生胶门尼黏度和在50 m in时的300%定伸应力偏高于产品优级品要求。展开更多
文摘The scientific and technical history of polymerization can be divided into three periods, which will be illustratedfor emulsion polymerization. The first period was when emulsion polymers were originally produced, and was developed asan attempt to copy natural rubber latex. Indeed, the natural process is quite different from the synthetic process of emulsionpolymerization, which in fact does not even need an emulsion to be present: the term is a misnomer! The results werefunctional but limited. In the second period, the first theories appeared, and a huge range of products was madefor surface coatings, adhesives, commodity polymers such as SBR, neoprene, etc. The work of the outstanding pioneers wasbased on limited types of experimental data, and some suppositions are now seen to be incorrect. Nevertheless, manyexcellent products were made and have evolved to many materials currently in everyday use. The third period of emulsionpolymerization is now dawning. The scientific efforts of many teams over previous decades, aided by the advent of newphysical techniques for investigation, have resulted in better understanding of the fundamentals of emulsion polymerizations.Some examples from the author's group involve creating novel materials using controlled seeded emulsion polymerizationfrom natural rubber latex and other polyenes. Latex topology and controlled free-radical chemistry can be combined toproduce a) a comb polymer with hydrophobic backbone and hydrophilic 'teeth', or b) with sufficient in situ compatibilizerbetween two otherwise incompatible polymers to yield a spatially uniform material down to the nanostructure level, and c) toproduce controlled nanostructures.
基金Supported by the National Natural Science Foundation of China(50573005)
文摘A novel multifunctional macromolecular organolithium initiator （PD-Sn-（RLi）3） was prepared via living anionic polymerization and used for the synthesis of miktoarm star copolymers in cyclohexane. The average molecular weight, polydispersity index, microstructure and unit composition of the miktoarm star copolymers were characterized with GPC and 1H-NMR. Performances of the miktoarm star styrene-butadiene rubbers were investigated in comparison with those of the blend rubbers such as the tin-coupled star-shaped random copolymers of styrene-butadiene rubber（S-SBR）/natural rubber （NR） blend rubber and S-SBR/Cis-1, 4-polybutadiene rubber （Cis-BR） blend rubber.
文摘以吉林石化公司有机合成厂的乳聚丁苯橡胶(SBR)生产配方为标准配方,研究了聚合反应时间对转化率的影响,分析了提高转化率对SBR的生胶门尼黏度、结合苯乙烯含量、凝胶含量、相对分子质量及其分布、胶乳黏度等基本性能的影响。结果表明,在标准配方条件下,延长聚合反应时间,转化率可以达到70%。转化率为70%时所得SBR与转化率为62%时所得SBR相比,前者的生胶凝胶含量和胶乳黏度均增大了1倍,数均相对分子质量、重均相对分子质量和Z均相对分子质量均高于后者,相对分子质量分布变宽,且前者的生胶结合苯乙烯含量能够达到产品标准,而生胶门尼黏度和在50 m in时的300%定伸应力偏高于产品优级品要求。
