苯乙烯-间戊二烯交替共聚物环氧化研究

The Study of Epoxidation of Styrene/1,3-Pentadiene Alternating Copolymer

苯乙烯(ST)-间戊二烯(PD)通过阴离子聚合可以合成交替序列共聚物SP,基于此序列的嵌段共聚物在抗冲击高透明树脂、增韧树脂等领域有极大应用价值,同时极性化改性聚烯烃材料对提升产品相容性、耐氧化、耐热性及透明性有重要意义。本文以间氯过氧化苯甲酸(m-CPBA)为环氧化试剂对SP进行环氧化改性研究,考察了反应温度、溶剂、SP分子量及环氧化剂类型对环氧化反应的影响。通过核磁氢谱(1H-NMR)和傅里叶红外光谱(FTIR)对环氧化SP产物(eSP)进行了结构表征。同时建立了不同环氧度eSP的定量分析方法,并通过正交实验确定了本实验所采用实验条件的最优反应条件:四氢呋喃(THF)/环己烷(CH)混合溶剂、温度343 K、C—C/m-CPBA摩尔比为1∶1.25、反应时间60 min,可以实现SP的完全环氧化。最后利用示差扫描热量仪(DSC)分析了不同环氧度eSP的玻璃化转变温度(Tg),证明环氧化改性改善产品极性的同时也能显著提升聚烯烃使用温度。

Styrene(ST)/1,3-pentadiene(PD)can undergo anionic polymerization to synthesize a special alternating sequence copolymer(SP)with BuLi as initiator.Interestingly,the multi-block copolymer based on this unique alternating sequence has great application value in the fields of high impact resistant,high transparent and toughened resin and so on.Furthermore,the polarity-modification of unsaturated polyolefin materials is of great research significance,for example,improving the compatibility and heat/weather resistance as well as transparent characteristics.In this paper,m-CPBA was used as the epoxidation reagent to study the epoxidation modification of SP.The effects of reaction temperature,solvent,SP molecular weight and epoxidation reagent on the epoxidation reaction were investigated in detail.The resultant epoxidation product(eSP)was characterized by proton nuclear magnetic resonance(1 H-NMR)and Fourier transform infrared spectrometry(FTIR).In addition,the quantitative analysis method of eSP with different epoxidation degrees was well established,and the optimal reaction conditions were determined through orthogonal experiments:tetrahydrofuran(THF)/cyclohexane(CH)as solvent,T=343K,n(C—C)/n(m-CPBA)=1∶1.25,t=60min,which can realize the complete epoxidation of SP.Finally,Tgs of eSPs with different epoxidation degrees were analyzed by differential scanning calorimeter(DSC),which proved that epoxidation could significantly improve the polarity of products and the service temperature of polyolefins.