Selected Thermoplastic Resins

Thermoplastic resins are, for convenience, referred to using abbreviations or acronyms listed in Appendix 15. The general properties of a range of thermoplastics, which are all used 

Amorphous thermoplastic polymers have polymer chains in a random coil arrangement without any degree of local order, whereas a semi-crystalline polymer would have some degree of order of the polymer chains. The chains are entangled and because they are not fixed, can slip past one another, whereas a thermoset resin, when subjected to local stress breaks, in a brittle maimer. The ability of the thermoplast to dissipate energy by chain slippage confers the property of toughness to the composite. 

Semi-crystalline thermoplastics (e.g. PEEK) are more efficiently reinforced by carbon fibers than amorphous thermoplasts (e.g. PES) because the fibers act as nucleation sites for 

Since water acts as a plasticizer, when the polymer absorbs water, the strength and stiffness decrease, but the toughness increases. Although, if the polymer is reinforced with carbon fiber, less water is absorbed since the carbon fiber replaces some of the polymer and will consequently absorb less water. Also, addition of the fiber will increase the dimensional stability with respect to temperature change, since the fiber has a much lower thermal expansion coefficient. On the other hand, a molding that exhibits preferred orientation can create warping, which occurs due to stresses arising from the differences in thermal expansion in the transverse and flow direction. 

Creep becomes more significant above the Tg and the addition of a fiber reinforcement inhibits the molecular mobility and hence improves the creep resistance at higher temperatures. The effect is greater with amorphous polymers, as crystalline polymers will inhibit creep anyway. 

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Fig. 1. US total sales and captive use of selected thermoplastic resins by major market for 2001. Major market volumes are derived from plastic resins sales and captive use data as compiled by VERIS Consulting, LLC and reported by the American Plastics Council s Plastic Industry Producers Statistics Group. Selected thermoplastics are low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, nylon, polyvinyl chloride, thermoplastic polyester, engineering resins, acrylonitrile-butadiene-styrene, styrene-acrylonitrile, other styrenics, polystyrene, and styrene butadiene latexes. (Data from ref. 25.)...

Total Sales Captive Use of Selected Thermoplastic Resins by Major Market, 2000-2004 (millions of pounds diy weight basis)... 

Table 9.4 Solubility of Selected Thermoplastic Resins In Furfural (46)...

Total Sales Captive Use of Selected Thermoplastic Resins by Major... 

USP acid test analy chem A United States Pharmacopoeia test to determine the carbonizable substances present In petroleum white oils. yti es pe as ad. test) UV stabilizer chem Any chemical compound that, admixed with a thermoplastic resin, selectively absorbs ultraviolet rays used to prevent ultraviolet degradation of polymers. Also known as ultraviolet stabilizer. yu ve sta ba.iTz ar)... 

The function of the resin matrix material in filament-wound structures is to help distribute the load, maintain proper fiber position, control composite mechanical and chemical properties, and provide interlaminar shear strength. Either a thermosetting or a thermoplastic resin material may be selected. Thermosetting resins may be selected for application in a wetwinding process or as part of a prepreg resin system. 

The decorative laminates described in the previous chapter are made with selected thermosetting resins while resins of this type can be moulded and extruded by methods similar to those outlined in the present and the next chapter the materials employed for these processes predominantly are thermoplastic. Many such plastics can be moulded and extruded under suitable conditions, the most important in terms of quantities used being those that combine properties satisfactory for the purpose with convenience in pro-cessing-especially the polyolefins (polyethylene and polypropylene), poly(vinyl chloride), and styrene polymers and blends. Other plastics with special qualities, such as better resistance to chemical attack, heat, impact, and wear, also are used—including acetals (polyformaldehyde or polyoxymethylene), polyamides, polycarbonates, thermoplastic polyesters like poly(ethylene terephtha-late) and poly(butylene terephthalate), and modified poly(phenylene oxide),... 

UV stabilizer Any chemical compound which, when mixed with a thermoplastic resin, selectively absorbs UV rays. 

MATERIALS. Selection of a base polymer thermoplastic resin from which a molded substrate is produced is influenced by factors of price and performance. Secondary considerations include supplier preference. Given the uniqueness of each product application, standardization of generic polymers is unlikely. In fact, the selection possibilities are likely to grow with continued diversification of application requirements/specifications. 

MC can be prepared by dissolution of either the rigid-rod polymer in a monomer that subsequently can be polymerized or by dissolving monomer of the rigid-rod polymer in a thermoplastic resin and then polymerizing it. The selections of the soluble monomer/polymer pair as well as control of the polymerization and phase... 

Impact modifiers are used in a wide variety of thermoplastic resins to absorb the energy generated by impact and dissipate it in a nondestructive fashion. The behavior and definition of impact modifiers are complex. The selection of an impact modifier is dependent on compatibility, physical solubility, impact performance, and cost. 

Prabhakaran, R.T.D., Andersen T.L. and Lystrup,A. (2011a), Attribute based selection of thermoplastic resin for vacuum infusion process A decision making methodo ogy InternationalJoumalofManufacturing,MateriabandMechanical Engineering, Vol. 1, Issue 3, pp. 31-52. 

The thermoforming process is the method for annealing a sheet of thermoplastic resin to manufacture the final product by vacuum or air pressure, as shown in Fig. 6.9. It has these advantages The cost of equipment is inexpensive, the processing of multilayer sheets can be readily achieved, and the production of thin products is possible. The disadvantages of this process are that the procedure for preparing sheets is necessary, the selection of available plastic material is limited, and manufacturing with accurate dimensions is difficult. 

End-use conditions will dictate which resin is best suited for which apphcations. Part testing at the conditions of the final apphcation is always recommended when one is selecting a thermoplastic resin. There are many performance featiures to balance. No single material fills all needs, which is why so many polymers coexist in the marketplace. 

Durai Prabhakaran RT, Lystrup A, Andersen TL. Attribute based selection of thermoplastic resin for vacuum infusion process a decision making methodology. International Journal of Manufacturing, Materials and Mechanical Engineering, 2011 1(3) 31-52. DOI 10.4018/ijmmme.2011070104. 

In the case of RTRP piping, the Uner is considered the first tine of defense and therefore a critical factor in corrosive service selection. Special resin liners, which may be deposited in extra thicknesses, are available for extra protection. Pipes with thermoplastic liners are also available. 

There are two alternates in matrix selection, thermoplastic and thermoset, and there are many matrix choices available within the two main divisions. The basic difference between the two is that thermoplastic materials can be repeatedly softened by heat, and thermosetting resins cannot be changed after the chemical reaction to cause their cure has been completed. The two alternatives differ profoundly in terms of manufacture, processing, physical and mechanical properties of the final product, and the environmental resistance of the resultant composite. 

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