用十二烷基硫酸钠(SDS)为乳化荆,十六醇(CA)为难溶助荆,以偶氮二异丁腈(AIBN)引发醋酸乙烯酯(VAC)进行细乳液聚合.在聚合体系中预先引入了聚合物,研究了聚合物、温度、引发剂浓度对细乳液转化率的影响,得出聚合物的引入可以显著加快聚合反应速率,聚合物用量宜控制在单体用量的2%,反应的表观活化能为38.6 kJ/mol,聚合速率与引发剂浓度的0.24次方成正比.
Polyvinyl acetate (PVAc) was prepared by mini-emulsion polymerization of vinyl acetate with azobisisobutyronitrile (AIBN) as initiator, and sodium dodecyl sulfate (SDS)/cetyl alcohol (CA) as surfactant/ consurfactant. The effects of the initiator concentration, temperature, hydrophobe and VAC/H_2O ratio on conversion were investigated. The results show that the addition of hydrophobe can significantly increase the reaction rate of polymerization due to the viscosity of monomer droplet can be increased by addition of hydrophobe so that free radical can be difficult to escape out of droplet with long active free radical life and auto-acceleration early occurs. It is also a reason that the existence of hydrophobe can prevent the monomer droplet from disappearing before the monomer droplet absorbed the active free radical. The discussion showed that it is suitable to control the hydrophobe in the amount of 2% of VAc. and It is obtained that the apparent polymerization activation energy is 38.6 kJ/mol which indicate that mini-emulsion polymerization of VAc possess high reaction activities. The apparent reaction order for AIBN is 0.24, which shows that the AIBN concentration has no significant effect on the reaction rate.
参考文献
| [1] | Chai XS;Schork FJ;Oliver EM .ATR-UV monitoring of methyl methacrylate miniemulsion polymerization for determination of monomer conversion[J].Journal of Applied Polymer Science,2006(4):1471-1475. |
| [2] | Jose M.Asua .Miniemulsion polymerization[J].Progress in Polymer Science,2002(7):1283-1346. |
| [3] | Anderson CD.;Sudol ED.;El-Aasser MS. .Elucidation of the miniemulsion stabilization mechanism and polymerization kinetics[J].Journal of Applied Polymer Science,2003(14):3987-3993. |
| [4] | Landfester K. .Polyreactions in miniemulsions [Review][J].Macromolecular rapid communications: Publishing the newsletters of the European Polymer Federation,2001(12):896-936. |
| [5] | X.Q.Wu;F.J.Schork .Kinetics of Miniemulsion Polymerization of Vinyl Acetate with Nonionic and Anionic Surfactants[J].Journal of Applied Polymer Science,2001(7):1691-1699. |
| [6] | Wang CC.;Chen CY.;Kuo JF.;Yu NS. .KINETIC STUDY OF THE MINI-EMULSION POLYMERIZATION OF STYRENE[J].Polymer: The International Journal for the Science and Technology of Polymers,1996(12):2509-2516. |
| [7] | 乔晋忠,张巧玲,程原.细乳液聚合法合成高分子量聚乙烯醇的研究[J].高分子学报,2007(02):124-129. |
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