Microgel formation in emulsion copolymerization: II. Seeded polymerization

✍ Scribed by Hidetaka Tobita; Yasunori Yoshihara

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 682 KB
• Volume: 34
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(199606)34:8<1415::aid-polb3>3.0.co;2-r

✦ Synopsis

SYNOPSIS

Microgel formation in seeded emulsion copolymerization of methyl methacrylate and ethylene glycol dimethacrylate is investigated both experimentally and theoretically. By introducing seed latex, the network structure development can be changed significantly. Even when the crosslinking density development takes a similar pattern as the crosslinking copolymerization in homogeneous media, the molecular weight development shows both types of behavior that is characteristic of emulsion polymerization without seed latex and of homogeneous polymerization, depending on the primary polymer chain length and the mole fraction of the divinyl monomer used. Once the microgels are formed, the weightaverage molecular weight increases just linearly with conversion due to a very small locus of polymerization. The present investigation reveals important characteristics of gelation phenomena in a limited space.