POLYMER PARTICLES AND RELATED ARTICLES

摘要

Process for preparing polymer, e.g., polystyrene, particles that may not or may contain a water-retaining agent and that require only a one-step process for incorporating the water-retaining agent. The polymer particles may be prepared via an extrusion process, or a bulk polymerization process wherein a water-retaining agent is blended into the polymer melt. Water is incorporated into the particles by soaking them in hot or cold water or treating the particles with steam for a predetermined time depending on the desired water content in the particles. The water-retaining agent may be starch, zeolite, silica dioxide or poly (N-isopropyl acrylamide) ranging from 0.1% to 10.0% by weight. The particles can be expanded via appropriate means to form pre-expanded or expanded particles in a conventional manner. These polymer particles may be used via conventional means to produce an article and the article may be soaked in hot or cold water or steam can be applied to the article to introduce a desired amount of water into the particles in the article and than expanded via hot air, steam, etc. to form a foamed polymer article.