含结合水的钯二亚胺催化剂催化1-辛烯水相均聚及共聚合研究

Water phase homo-and copolymerization of 1-octene catalyzed by a palladium(Ⅱ)-α-diimine complex with bound water

以含结合水的钯二亚胺[(ArNC(An)—C(An)NAr)Pd(CH2)3C(O)OMe](BAr’4).H2O为催化剂,以水为分散介质,进行了1-辛烯均聚合及1-辛烯与丙烯酸甲酯(MA)的共聚合反应,通过GPC、DSC、1H-NMR、光散射测定了聚合物的分子量、熔点、分子结构以及聚合物粒子的粒径。结果表明:该催化剂在水相聚合体系中可以催化1-辛烯的均聚合及1-辛烯与MA的共聚合反应;得到的聚合物重均分子量均可达3.3×104以上,且分子量分布较窄(Mw/Mn在1.4～2.1之间);共聚物为半结晶性聚合物,Tg为-34.8℃,Tm为32.3℃,聚合所得均聚物和共聚物的支化度均较高;共聚合可得到较为稳定的乳液体系,光散射测得乳胶粒子的粒径约为266 nm。

The homopolymerization of 1-octene and copolymerization of 1-octene with methyl acrylate （MA） were carried out in water using a palladium（ll）-a-diimine complex including bound water [ （ArN =C（ An）-C（ An）= NAr）Pd（CH2）3C（O）OMe] （BAr＇4） -H20 （Ar =2,6- （i-Pr）2C6H3 ;Ar＇=3,5-（CF3）2C6H3） ） as the catalyst. The particle diameter, melting point, molecular weight and architecture of the polymers were investigated by light scattering, gel permeation chromatography （GPC） , differential scanning calorimetry （DSC） and 1H nuclear mag- netic resonance （NMR） spectroscopy, respectively. The results suggested the polymerization was carried out suc- cessfully in water and the resulting polymers had relatively high molecular weight and narrow molecular weight distribution （Mw/Mn） , ranging between 1.4 and 2. 1. In addition, a higher degree of branching was observed in the products as compared with those by obtained by solution polymerization for the eopolymer. The copolymerization latex was stable and the particle diameter was about 266 nm. Moreover, the copolymers obtained were hypoerystalline and the values of the glass transition temperature （ T ） and melting temperature （ Tm ） were about - 34. 8 ℃ and 32.3 ℃ , respectively.