丙烯酸2-乙基己酯辐射乳液聚合

RADIATION INDUCED EMULSION POLYMERIZATION OF 2-ETHYLHEXYL ACRYLATE

研究了丙烯酸2-乙基己酯辐射乳液聚合过程中反应速度与剂量率、乳化剂浓度、单体含量等因素的关系。发现反应速度与剂量率的指数依赖关系(R_p∝I^n)随起始单体含量的增大,n值由小变大,最后趋近于1;反应速度与乳化剂浓度的0.5-0.6次方成比例。对实验结果进行了讨论,并对静态下辐射引发的乳液聚合的成核机理作了初步探讨。

The effects of radiation dose rate concentration of emulsifier and mo-nomer content on reaction rate of radiation induced 2-ethylhexyl acrylate (EHA) emu-lsion polymerization have been studied. Nonionic surfactants, polyoxyethylene alky1etherperegolo 0 with HLB about 15 and polyoxyethylene nonylphenolether (emulsifier OP)with HLB 15, are used as the emulsifiers in this work. It has been found that thedependence of R. on I (R_p∝I') is changed with the index n from 0.29 for M/W =2/8 (monomer/water in volume) to 0.91 for 5/5, where [E] of peregolo 0 is 4%.It has also been found that R_p∞[E]^(0.58) for peregolo 0 and R_p∞[E]^(0.51) for emulsifierOP. In order to interpret the results sufficiently, both micellar nucleation and microd-roplet nucleation have been taken into account for the emulsion polymerization of thepresent system irradiated without agitation, especially for the case with a higher M/Wvalue the later may be the main nucleation process.