Premium
Synthesis and Characterization of Poly (Acrylic Acid‐co‐Divinylbenzene) Microgels by Ultrasonic Degradation
Author(s) -
Kim YoungJune,
Kim KongSoo,
Park MyungHwan
Publication year - 1992
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.4990270304
Subject(s) - divinylbenzene , copolymer , materials science , polymer chemistry , styrene , acrylic acid , monomer , azobisisobutyronitrile , gel permeation chromatography , polymerization , chemical engineering , polymer , composite material , engineering
The preparation of pure microgels in high yield was investigated by a new method which restricts the intermolecular crosslinking reaction between second‐stage crosslinked products by steric hindrance of the first‐stage crosslinked products. This is followed by ultrasonic degradation of the first‐stage crosslinked products. The first‐stage crosslinked products were prepared by copolymerization of styrene and divinylbenzene monomer in dioxane. with α,α′‐azobisisobutyronitrile as initiator. The second‐stage crosslinked products were prepared by copolymerization of acrylic acid and divinylbenzene monomer in first‐stage crosslinked products highly swollen in dioxane, using α,α′‐azobisisobutyronitrile as initiator. Degradation of first‐ and second‐stage crosslinked products was carried out using an ultrasonic vibrator. The characteristics of the crosslinked products synthesized were investigated by gel permeation chromatography, dynamic laser light scattering and electron microscopy. It was found that the styrene‐divinylbenzene gel of high molecular weight was scissioned preferentially with increasing ultrasonic degradation time and that ultrasonic degradation of compact and small size crosslinked products was very difficult. The crosslinked poly(acrylic acid)s are small compact microgels having a very narrow size distribution of 20‐30 nm diameter. A pure microgel at nearly 100% conversion was obtained by the new preparation method suggested in this study.