沉淀聚合制备P( PETA - St)微球中溶剂对微球形成的影响

以季戊四醇三丙烯酸酯(PETA)和苯乙烯(St)为单体,在系列二元混合溶剂中用沉淀聚合法探讨制备P(PETA St)微球的实验条件.选择不同溶剂,调整两种溶剂的体积比来改变其三维溶度参数,并对制备的聚合物微球进行表征.结果发现:以甲醇和乙醇或者甲醇和乙酸乙酯为二元混合溶剂时,只有当混合溶剂的极性溶度参数δp和氢键溶度参数δh的值分别在8.8～12.3 MPa1/2和17.0 ～22.3 MPa1/2之间时才能形成微球,而混合溶剂的色散溶度参数δd变化不大；以水和丙酮为混合溶剂时δp和δh的值分别在11.5～16.0 MPa1/2和14.1～42.4 MPa1/2范围内时,可以获得形貌较规则的P(PETA -St)微球.由此推断,P(PETA -St)微球的形态主要由混合溶剂的δp和δh值决定.

Effect of Solvent on the Morphology of Poly(PETA-St) Microspheres Prepared by Precipitation Polymerization.

Microspheres were obtained via precipitation polymerization with pentaerythritol triacrylate(PETA) and styrene(St) as monomers in binary mixture of solvents.By adjusting the composition of the binary solvent mixtures,continuous and smooth variations in the three-dimensional solubility parameters were achieved,and precipitation polymerization was conducted with these binary solvents of designed solubility parameters.The prepared polymer microspheres were characterized.Results show that,in the binary solvent of methanol-ethanol or methanol-ethyl acetate,polymer microspheres are obtained only when the polar component of the solubility parameter(δp) is between 8.8~12.3MPa1/2 and the hydrogen bonding component(δh) is between 17.0~22.3MPa1/2,while the dispersion force component(δd) does not show perceptible variation.Whereas when the binary solvent of water and acetone is used,uniform microspheres are achieved when δp and δh are between 11.5～16.0MPa1/2 and 14.1～42.4MPa1/2,respectively.