Effects of 2-hydroxyalkyl methacrylates on the styrene miniemulsion polymerizations stabilized by SDS and alkyl methacrylates

✍ Scribed by Chorng-Shyan Chern; Jih-Cheang Sheu

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 229 KB
• Volume: 38
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/1099-0518(20000901)38:17<3188::aid-pola180>3.0.co;2-y

✦ Synopsis

The effects of 2-hydroxyalkyl methacrylates (HEMA and HPMA) on the styrene miniemulsion polymerizations stabilized by SDS/lauryl methacrylate (LMA) or SDS/stearyl methacrylate (SMA) were investigated. A mixed mode of particle nucleation (monomer droplet nucleation and homogeneous nucleation) is operative during polymerization. Homogeneous nucleation plays a crucial role in the polymerizations stabilized by SDS/LMA, whereas monomer droplet nucleation becomes more important in the polymerizations stabilized by SDS/SMA. The polymerization kinetics is insensitive to the type of 2-hydroxyalkyl methacrylates, but the difference in the relative importance of monomer droplet nucleation and homogeneous nucleation is detected. Incorporation of 1-pentanol (C 5 OH) into the reaction mixture also shows a significant influence on the polymerizations stabilized by SDS/LMA or SDS/SMA. This is attributed to the formation of a close-packed structure of SDS and C 5 OH on the droplet surface, which acts as a barrier to the incoming oligomeric radicals.