Synthesis and Characterization of Trans-1,4-butadiene/Isoprene Copolymers: Determination of Sequence Distribution and Thermal Properties

Abstract Two series of trans-1,4-poly（butadiene-co-isoprene） copolymers （TBIR） were prepared using the catalyst system TiCl4/MgCl2-Al（i-Bu）3 at different reaction temperatures. All dyad and triads sequence distributions, the number-average sequence length and the sequence concentration of the copolymers were calculated according to 13C-NMR spectra. The influences of temperature and initial molar ratio of butadiene to isoprene （Bd to Ip） on the distribution of the chain segments in the TBIR copolymers were discussed. The correlation of copolymer compositions and thermal properties were also evaluated, which facilitated the understanding of controlling the degree of crystallinity and the transition tempera^re by changing Bd content and temperature.

Synthesis and Characterization of trans-1,4-Butadiene/Isoprene Copolymers: Determination of Monomer Reactivity Ratios and Temperature Dependence

A series of trans-1,4-butadiene/isoprene copolymers were prepared using the catalyst system TiCl4/MgCl2-Al（i- Bu）3 with bulk precipitation technology at different temperatures. Monomers reactivity ratios were calculated based on the Kelen-Tiid6s （K-T） method and the Mao-Huglin （M-H） method. The influence of temperature on copolymer composition and polymerization rate was discussed in detail. The increase of reaction temperature brought the decrease of butadiene reactivity ratio rBd and supplied an effective adjustment on copolymers＇ composition distribution.

磺化丁基橡胶离子聚合体及其与PP或HDPE共混物的性能

通过乙酰硫酸在石油醚中与丁基橡胶(IIR)作用,再分别用Ce^(3+)、Al^(3+)和乙胺中和,制得了3种磺化IIR离子聚合体。对离子聚合体的性能及其与聚丙烯(PP)、高密度聚乙烯(HDPE)共混的流变性质及其共混物的力学性能进行了研究。结果表明,用20％(质量,下同)硬脂酸锌增塑的磺化IIR铈离子聚合体(GeS-IIR)的加工性能和力学性能均较好。用10％硬脂酸锌增塑的磺化IIR乙胺离子聚合体同PP共混呈现协同效应,同HDPE共混呈现加和效应。用20％硬脂酸锌增塑的CeS-IIR同HDPE共混呈现抵消效应。用Al^(3+)或Ce^(3+)中和的磺化IIR离子聚合体的熔融粘度较低、永久变形较小,可作为热塑性弹性体,但强度较乙胺中和的为低。