## Abstract Thermomechanical degradation, as a result of mixing at 175°C during the preparation of polystyrene composites containing monodisperse (0.45μm) crosslinked polystyrene beads, often leads to a uniform decrease in rheological properties on increasing the concentration or on reducing the cr
Model filled polymers. I. Synthesis of crosslinked monodisperse polystyrene beads
✍ Scribed by D. Zou; V. Derlich; K. Gandhi; M. Park; L. Sun; D. Kriz; Y. D. Lee; G. Kim; J. J. Aklonis; R. Salovey
- Book ID
- 105337546
- Publisher
- John Wiley and Sons
- Year
- 1990
- Tongue
- English
- Weight
- 892 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0887-624X
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Monodisperse crosslinked polystyrene beads of varied size and crosslink density are prepared by emulsion copolymerization of styrene and divinylbenzene in the absence of emulsifier. Tumbling and internally stirred reactors were used for synthesis, with minimal agglomeration at at least 0.22 wt % potassium persulfate and up to 10% by weight of styrene in aqueous emulsion in the absence of oxygen. Particle sizes decreased from 800 to 200 nm on raising the polymerization temperature from 60 to 95°C. The glass transition temperature of the beads increased from 104.4 to 133°C by the inclusion of up to 10% by weight of divinylbenzene. The thermal stability of the beads was higher for peroxide than for persulfate initiation. The crosslink density estimated from the degree of swelling was about one third that expected from stoichiometry. The polystyrene beads are used as filler particles in polymer composites.
📜 SIMILAR VOLUMES
## Abstract The steady shear viscosity and dynamic moduli, at 180 and 200°C, of polystyrene composites, containing cross‐linked monodisperse polystyrene beads varying in diameter from 0.2 to 0.8 μm, are independent of bead size and cross‐link density, but increase with the volume fraction of beads.