considered to be the polymer analogue of grains in polycrystalline metals and ceramics

Polymers are neither as strong nor as stiff as metals. However, their high flexibilities, low densities, and resistance to corrosion make them the materials of choice for many applications.

This behavior is characterized by the relaxation modulus, a time-dependent modulus of elasticity.

Fracture strengths of polymeric materials are high relative to those of metals and ceramics.

Tensile modulus is relatively insensitive to molecular weight.

Thru _________________ stiffness and strength are enhanced by permanently deforming the polymer in tension.

Deformation corresponds to the unkinking and uncoiling of chains in response to an applied tensile stress.

The crosslinking process in elastomers, which is achieved by a nonreversible chemical reaction, typically carried out at an elevated temperature.

randomly oriented molecules in the liquid phase transform into chain-folded crystallites that have ordered and aligned molecular structures

The ___________________ of crystalline regions of a polymer corresponds to the transformation of a solid material having an ordered structure of aligned molecular chains into a viscous liquid in which the structure is highly random.

Upon cooling, this phenomenon corresponds to the gradual transformation from a liquid into a rubbery material, and finally into a rigid solid.

Polyethylene, polypropylene, poly (vinyl chloride), polystyrene, and the fluorocarbons, epoxies, phenolics, and polyesters are example of what?

Used primarily in textiles. Mechanical, thermal, and chemical characteristics of these materials are especially critical.

These materials have unusual properties and are used in a host of high-technology applications.

The synthesis of high-molecular-weight polymers.

A polymerization where the monomer units are attached one at a time in chainlike fashion to form a linear molecule.

A polymerization which involves stepwise intermolecular chemical reactions that may include more than a single molecular species.

The properties of polymers may be further modified by using additives; these include fillers, plasticizers, stabilizers, colorants, and flame retardants.

They are added to improve the strength, abrasion resistance, toughness, and or thermal/dimensional stability of polymers.

They are added to enhance flexibility, ductility, and toughness.

They are added to to impart specific colors to polymers.

They are added to enhance flammability resistance of polymers.

Are frequently applied to the surface of materials to serve one or more of the following functions: (1) to protect the item from the environment, which may produce corrosive or deteriorative reactions; (2) to improve the item’s appearance; and (3) to provide electrical insulation.

A stable suspension of small, insoluble polymer particles dispersed in water.

Substance used to bond together the surfaces of two solid materials.

Are fabricated and used extensively as bags for packaging food products and other merchandise, as textile products, and in a host of other uses.

Plastic materials that contain a relatively high volume percentage of small pores and trapped gas bubbles. Commonly used as cushions in automobiles and furniture, as well as in packaging and thermal insulation.