三氟化硼-乙醚络合物催化γ-戊内酯与ε-己内酯开环共聚的研究

以三氟化硼乙醚络合物为催化剂,进行了γ-戊内酯(γ-VL)与ε-己内酯(ε-CL)的本体开环共聚的研究.采用1H -NMR、13C- NMR证实了所得共聚物的结构,并对共聚物的分子量、组成、熔点等进行了表征.结果表明,在一定的条件下,难以均聚的γ-VL可与ε-CL发生共聚反应,从而在共聚物链结构中引入少量的γVL单元.γVL单元的引入使得共聚物的分子量和熔点下降.由K- T法估算出两种单体共聚的竞聚率分别为r(ε-CL)=17.6,r(γ-VL)=0.0078.

RING-OPENING COPOLYMERIZATION OF γ-VALEROLACTONE ANDε-CAPROLACTONE CATALYZED BY BORON TRIFLUORIDE ETHERATE

Bulk ring-opening copolymerization of γ-valerolactone (γ-VL) and ε-caprolactone (ε-CL) was carried out with boron trifluoride etherate complex (BF_3·OEt_2) as catalyst. The structures of the resultant copolymers were determined by 1H-NMR and 13C-NMR spectroscopies. The molecular weight, composition and melting point of the copolymers were characterized by means of GPC, 1H-NMR and DSC, respectively. Although being unable to ring-opening homopolymerize, γ-VL was ring-opening copolymerized with ε-CL to give copolymers P(γ-VL-co-ε-CL) containing certain amount of γ-VL unit. The introduction of γ-VL unit resulted in significant decrease of the molecular weight and melting point of the copolymers. The reactivity ratio of ε-CL and γ-VL was estimated as 17.6 and 0.0078, respectively, by the K-T method.