Glossary Of Terms
thermoplastics
Polymers that can be melted by heating and solidified by cooling, and may be re-melted repeatedly. Thermoplastics are elastic and flexible above each resin’s specific glass transition temperature. Depending on the temperature, most thermoplastics have a crystalline region (giving them strength and rigidity) and an amorphous region (giving them elasticity). Amorphous thermoplastics do not crystallize and are most often used in applications where clarity is important.

Other materials include copolymers, thermoplastic elastomers (TPE) and acid copolymers (ionomers) like the following:

  • Ethylene vinyl acetate (EVA) is a copolymer of ethylene and vinyl acetate. It approaches elastomeric materials in softness and flexibility but can be processed like other thermoplastics. It has good clarity, low temperature toughness, stress resistance, and resistance to UV radiation. EVA is used as a coating for nylon and polypropylene, among other materials. It adheres well to a variety of substrates.

  • Santoprene™ is a thermoplastic polyolefine elastomer (TPE). It is created by mixing EPDM rubber and polypropylene to produce a material with the flexibility and durability of rubber plus the ability to withstand greater temperature extremes. Santoprene is a type of TPE known as a thermoplastic vulcanizate (TPV), part of the class of flexible polymers. Introduced by Monsanto in 1981, it was positioned as a bridge between thermosets and thermoplastics. Compared to physically blended and reactor-made thermoplastic polyolefins, TPVs have better high temperature resistance, low impact properties, resistance to UV radiation, low compression set, and fatigue resistance. Santoprene is not radio-opaque.

  • Surlyn™ is a thermoplastic resin created by combining acid copolymers (such as ehylene/methacrylic acid) and metal salts. Acid neutralization results, forming ion clusters within the polymer matrix and giving these resins the general class name of "ionomer." The chemical resistance, melting range, density, and basic processing characteristics of Surlyn are similar to those of ethylene-based copolymers, but it has better low temperature impact toughness, abrasion and chemical resistance, transparency and clarity, melt strength, and adhesion to other products (such as polyurethane and metal or glass). Surlyn readily accepts colorants.

Microspec also works with customer-supplied custom and proprietary formulations.