摘要
在有机锂(BuLi)引发体系下,以双螺杆挤出机为反应器,苯乙烯、丁二烯混和物作为单体,THF(四氢呋喃)为极性添加剂,本体法一步合成了丁苯共聚物。通过多种表征手段,研究了THF的用量对共聚物结构和性能的影响。由1H-NMR谱图计算得知,THF的加入使1,2-聚丁二烯和无规苯乙烯含量明显增加,但THF/BuLi之比超过5以后,增加趋势减缓。采用H2O2/OsO4体系对聚合物分子链中的丁二烯双键进行了深度氧化降解,利用配备小角激光光散射仪的GPC对降解前后的样品进行了分析,结果表明随着THF/BuLi的增加,分子链中长嵌段聚苯乙烯的分子量和含量逐渐降低。TEM分析结果表明随着THF/BuLi的增加,两相界面逐渐变得模糊,两相的相容性增强。拉伸性能测试表明随着THF/BuLi的增加,使拉伸强度逐渐降低,当THF/BuLi=30时,屈服点消失。
Using a closely intermeshing twin-screw extruder as reactor,the mixed-up styrene（S） and butadiene（B） as the monomer and the different amounts of tetrahydrofuran（THF） as the polar additive,several kinds of novel styrene/butadiene copolymers（S/B） were synthesized by bulk polymerization with the organic lithium（BuLi） as initiator.The effects of the THF adding amount on the properties and structure of the S/B produced by the reactive extrusion method were studied.The 1,2-PBD（1,2-polybutadiene） and random styrene contents of the S/B were derived respectively from 1H-NMR spectrums.The results show that the contents of 1,2-PBD and random styrene increase obviously with the increase of THF adding amount,when the THF/BuLi is in excess of 5,the increasing trend will slow down.The PBD bond of S/B were cleaved by reacting them with hydrogen peroxide in the presence of osmium tetraoxide,and then the copolymers and the segments after oxidation were characterized by GPC cooperating with the multi-angle laser light scattering instrument（MALLS）.It was found that,after oxidation,the content and the molecular weight of the long PS（polystyrene） block decrease with the increase of THF/BuLi adding amount.The survey of TEM photographs of the copolymers prepared shows that,with the increase of the THF/BuLi adding amount,the interface between the continuous phase and dispersion phase is blurred and the compatibility of two phases increases.Finally,the tensile property tests of the S/B prepared were conducted,and it was found that the tensile strength decreases with the increase of THF/BuLi adding amount,and the yield point of the tensile curve disappears for the S/B with THF/BuLi additive equals to 30.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2008年第2期234-239,共6页
Journal of Chemical Engineering of Chinese Universities
基金
国家自然科学基金重大资助项目(50290090)
