3,3'-双叠氮甲基环氧丁烷-3-叠氮甲基-3'-甲基环氧丁烷无规共聚物的合成与结构表征

Synthesis and Structure Characterization of 3,3′-Bisazidomethyloxetane-3-azidomethyl-3′-methyloxetane Random Copolymer

以1,4-丁二醇/三氟化硼乙醚为引发体系,利用阳离子开环共聚合方法合成了3,3'-双叠氮甲基环氧丁烷(BAMO)与3-叠氮甲基-3'-甲基环氧丁烷(AMMO)的无规共聚物,探讨了以Lewis酸为催化剂时活性链端与活性单体相互竞争的聚合反应机理.同时根据GPC结果分析了聚合反应温度对产物分子量和分子量分布的影响.结果表明,在15℃时产物分子量可控且分布较窄.通过1H NMR和13C NMR对无规共聚物的共聚组成及微观序列结构进行了表征,结果表明,共聚组成中两单体的摩尔比接近于1∶1,与投料比一致;交替度接近50%,BAMO与AMMO链段的平均序列长度为2,其结构单元呈随机分布的状态.

3, 3＇-Bisazidomethyloxetane-r-3-azidomethyl-3＇-methyloxetane random eopolymer [ p （ BAMO-r- AMMO） 1 was synthesized by cationic ring opening polymerization using 1,4-butanediol/BF3/Et20 initiator system. Polymerization mechanism of active chain end and activated monomer was discussed in the presence of Lewis acid. The effect of polymerization temperature on molecular weight and molecular weight distribution of product was analysed by GPC. The results indicate that molecular weight is controllable and molecular weight distribution is relatively narrow under 15 ℃. 1H NMR and 13C NMR were also used to character composition and micro-sequential structure of random copolymer. The results show that the composition of copolymer is l： 1, which is accordance with molar feed ratio of monomers; alternating degree is nearly 50% ; average sequence length of chain segment is 2 for both BAMO and AMMO, so the two structural units are in random distribution.