The research of preparation of polyvinyl acetate with lower polydispersity index

Abstract

In this study, the way of preparing polyvinyl acetate (PVAc) with lower polydispersity index (PDI) was studied. By adding small amount of monomer with polar group, such as acrylic acid (AA), α-methacrylic acid (MAA), or acrylamide (AM), as modulation monomer, the polymerization was carried out at 65°C with a mechanical agitator using AIBN as initiator under N2 atmosphere. Effects of the mol ratio of modulation monomer/VAc and structure of the modulation monomer on the polymerization conversion, the molecular weight and molecular weight distribution of the obtained polymers were investigated through 1H NMR, gravity method, and gel permeation chromatography. The results show that by adding modulation monomer into the reactive system the PVAc with lower PDI could be got. With the increase of the modulation monomer amount, the conversion and the molecular weight decrease, and the PDI of the obtained polymer is lower. When the mol ratio of AA/VAc is 3 : 100, the PDI of the obtained polymer is 1.84. When the mol ratio of AM/VAc is 1 : 100, the PDI of the obtained polymer is 1.68, which is narrower than that without AM. All researches we have done laid a foundation for further study. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008