plastic: Composition and Types of Plastic
Composition and Types of Plastic
A plastic is made up principally of a binder together with plasticizers, fillers, pigments, and other additives. The binder gives a plastic its main characteristics and usually its name. Thus,
There are two basic types of plastic: thermosetting, which cannot be resoftened after being subjected to heat and pressure; and thermoplastic, which can be repeatedly softened and remolded by heat and pressure. When heat and pressure are applied to a thermoplastic binder, the chainlike polymers slide past each other, giving the material “plasticity.” However, when heat and pressure are initially applied to a thermosetting binder, the molecular chains become cross-linked, thus preventing any slippage if heat and pressure are reapplied.
See epoxy resins; polyacrylics; polycarbonates; polyethylene; polyolefins; polypropylene; polystyrene; polyurethanes; polyvinyl chloride; vinyl plastics.
Sections in this article:
- Introduction
- Development of Plastics
- Environmental Considerations
- Molding of Plastic
- Composition and Types of Plastic
- Bibliography
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2024, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Organic Chemistry