丙烯酸酯和甲基丙烯酸酯基团转移共聚研究

研究了三种丙烯酸酯分别和四种甲基丙烯酸酯的基团转移共聚，用１Ｈ ＮＭＲ法测定共聚物组成，扩展的Ｋｅｌｅｎ Ｔｕｄｏｓ法测定竞聚率，结果为γＭＡ＝９２３、γＭＭＡ＝００６；γＥＡ＝１４１５、γＭＭＡ＝００１；γＢＡ＝７５１、γＭＭＡ＝００２；γＭＡ＝１４４１、γＥＭＡ＝００１；γＭＡ＝１３９６、γＢＭＡ＝０２３；γＭＡ＝８６６、γｉ ＢＭＡ＝００８，表明基团转移聚合同阴离子聚合有明显的相似之处．

STATISTICAL GROUP TRANSFER COPOLYMERIZATION OF ACRYLATES WITH METHACRYLATES

Statistical group transfer copolymrization of acrylates with methacrylate have been performed for six binary systems using 1 methoxy 2 methyl 1 trimethylsilyloxy propene(initiator) and tetrabutylammonium bibenzoate(catalyst) in THF solution.The copolymer compositions were determined by 1H NMR spectroscopy and the results eval uated by the extented Kelen Tudos method.The monomer pairs concerned are (1) methyl acrylate (MA) and methyl methacrylate (MMA),(2) ethyl acrylate (EA) and MMA,(3) butyl acrylate (BA) and MMA,(4)MA and ethyl methacrylate (EMA),(5) MA and butyl methacrylate (BMA),(6) MA and iso butyl methacrylate (iBMA).The reactivity ratios were found to be γ MA =9 23, γ MMA =0 06; γ EA =14 15, γ MMA =0 01; γ BA =7 51, γ MMA =0 02; γ MA =14 41, γ EMA =0 01; γ MA =13 96, γ BMA =0 23; γ MA =8 66, γ i BMA =0 08.Anionic copolymerization of EA with MMA and MA with EMA was also carried out to compare with the result of GTP,the data are γ EA =9 67, γ MMA =0 11; γ MA =3 51, γ EMA =0 20.It was shown that acrylate is much more reactive than methacrylate for GTP and anionic copolymerization,the reactivity ratios are quity different from unity and show a high similarly.