Thermoplastic materials engineering plastics

PolyBCMO exhibits an excellent combination of physical-chemical-processing characteristics rendering it a competitive thermoplastic material (engineering plastic). 

Aromatic polyethers are best characterized by their thermal and chemical stabiUties and mechanical properties. The aromatic portion of the polyether contributes to the thermal stabiUty and mechanical properties, and the ether fiinctionahty faciUtates processing but stiU possesses both oxidative and thermal stabiUty. With these characteristic properties as well as the abiUty to be processed as mol ding materials, many of the aromatic polyethers can be classified as engineering thermoplastics (see Engineering PLASTICS). 

Advanced Thermoplastics Materials. Thermoplastics and linear plastics of finite molecular weight that can be fabricated into very complex stmctures by hot melt or injection mol ding are different from the thermoset materials that require cross-linking to build up infinite molecular weight to form network (cross-link) stmctures. Advances in thermoplastic engineering materials include amorphous thermoplastics, crystalline thermoplastics, Hquid crystal thermoplastics, and fluorinated thermoplastics (see Engineering plastics). 

Keywords. Saturated poly(ester-imide)s, Unsaturated poly(ester-imide)s, Imide modified alkyds, Imide modified coatings, Thermoplastic poly(ester-imide)s, Wire enamels, Impregnating materials, Engineering plastics, Other applications... 

Extmded engineering thermoplastic stock can be treated like other building material ia that it can be machined, cut, and fastened. However, none of the engineering plastics can be considered a one-for-one substitute for metals or wood. For example, impact resistance must be considered, and glues, paints, etc, must be screened for chemical aggressiveness and adhesion capabiUty. 

With the expiry of the basic ICI patents on poly(ethylene terephthalate) there was considerable development in terephthalate polymers in the early 1970s. More than a dozen companies introduced poly(butylene terephthalate) as an engineering plastics material whilst a polyether-ester thermoplastic rubber was introduced by Du Pont as Hytrel. Polyfethylene terephthalate) was also the basis of the glass-filled engineering polymer (Rynite) introduced by Du Pont in the late 1970s. Towards the end of the 1970s poly(ethylene terephthalate) was used for the manufacture of biaxially oriented bottles for beer, colas and other carbonated drinks, and this application has since become of major importance. Similar processes are now used for making wide-neck Jars. 

Many thermoplastics are now accepted as engineering materials and some are distinguished by the loose description engineering plastics. The term probably originated as a classiflcation distinguishing those that could be substituted satisfactorily for metals such as aluminium in small devices and structures from those with inadequate mechanical properties. This demarcation is clearly artificial because the properties on which it is based are very sensitive to the ambient temperature, so that a thermoplastic might be a satisfactory substitute for a metal at a particular temperature and an unsatisfactory substitute at a different one. 

When an engineering plastic is used with the structural foam process, the material produced exhibits behavior that is easily predictable over a large range of temperatures. Its stress-strain curve shows a significantly linearly elastic region like other Hookean materials, up to its proportional limit. However, since thermoplastics are viscoelastic in nature, their properties are dependent on time, temperature, and the strain rate. The ratio of stress and strain is linear at low strain levels of 1 to 2%, and standard elastic design... 

SPE,South Texas Section SPE,Thermoplastic Materials Foams Div. SPE,Polymer Modifiers Additives Div. Society of Plastics Engineers)... 

Thermoplastics are matching cheap conventional materials and, consequently, commodities are the most used with a pre-eminence of rigid and soft PVCs (Figure 2.23(b)). However, some engineering plastics are used for specific applications such as glazing, for example. 

Kapton - [ENGINEERING PLASTICS] (Vol 9) - [HEAT-RESISTANT POLYMERS] (Vol 12) - [PHTHALIC ACID AND OTHERBENZENEPOLYCARBOXYLIC ACIDS] (Vol 18) - [POLYMIDES] (Vol 19) -as composite matrix [COMPOSITE MATERIALS - POLYMER-MATRIX - THERMOPLASTICS] (Vol 7) -ion implantation m [ION IMPLANTATION] (Vol 14)... 

Retardants are mainly used as additives for plastics, particularly those used in the manufacture of electrical and electronic equipment. FRs are added to circuit boards, cables, coimectors, plugs, and house component devices. These compounds are used in the production of engineering plastics, thermoplastic and elastomeric elements, and insulation. Flame retardants can also be found in furniture, mattresses, carpets, curtains, clothing (mainly protective or sweatshirts for children), and polymeric materials used for the production of cars, buses, airplanes, and military equipment. FRs have been used wherever material must meet safety standards regarding flammability [87]. 

Brewer, G.W., "Properties of Thermoplastic Structural Foams," pp., 508-513 in Engineering Materials Handbook, Vol. 2 -Engineered Plastics, ASM International, Materials Park, Ohio (1988). 

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