Polycarbonate-based plastics

Table 18.6 Static charge decay rate of selected polycarbonate-based plastics.

Impact strength (impact resistance), 10 177 of polycarbonates, 19 810-811 of styrene-based plastics, 23 362-363 Impact testing, 19 580 Impact tests, for polymer blends, 20 352... 

Phenol is a key industrial chemical however, the output of phenol from coal tar is exceeded by that of synthetic phenol. Phenol is used for the production of phenol-formaldehyde resins, while other important uses in the plastics field include the production of polyamides such as nylon, of epoxy resins, and polycarbonates based on bisphenol A and of oil-soluble resins from p-t-butyl and p-octyl phenols. Phenol is used in the manufacture of pentachlorophenol, which is used as a fungicide and in timber preservation. Aspirin and many other pharmaceuticals, certain detergents, and tanning agents are all derived from phenol, and another important use is in the manufacture of 2,4 dichlorophenoxyacetic acid (2,4-D), which is a selective weed killer. 

SAE J1685, Classification System for Automotive Acrylonitrile/Butadiene/Styrene (ABS) and ABS + Polycarbonate Blends (ABS + PC) Based Plastics. ... 

Polycarbonate has good mechanical strength, is heat resistant, has dimensional stability, and is widely used as a general purpose engineering plastic. However, its viscosity, chemical resistance, and dependence of impact strength on wall thickness are not suitable for some applications. Idemitsu alloys are highly-functional polycarbonate-based polymer alloys. While retaining the best properties of polycarbonate the as above mentioned problems have been virtually eliminated. 

Usage of phosphoms-based flame retardants for 1994 in the United States has been projected to be 150 million (168). The largest volume use maybe in plasticized vinyl. Other use areas for phosphoms flame retardants are flexible urethane foams, polyester resins and other thermoset resins, adhesives, textiles, polycarbonate—ABS blends, and some other thermoplastics. Development efforts are well advanced to find appHcations for phosphoms flame retardants, especially ammonium polyphosphate combinations, in polyolefins, and red phosphoms in nylons. Interest is strong in finding phosphoms-based alternatives to those halogen-containing systems which have encountered environmental opposition, especially in Europe. 

Polypropylene has a chemical resistance about the same as that of polyethylene, but it can be used at 120°C (250°F). Polycarbonate is a relatively high-temperature plastic. It can be used up to 150°C (300°F). Resistance to mineral acids is good. Strong alkalies slowly decompose it, but mild alkalies do not. It is partially soluble in aromatic solvents and soluble in chlorinated hydrocarbons. Polyphenylene oxide has good resistance to ahphatic solvents, acids, and bases but poor resistance to esters, ketones, and aromatic or chlorinated solvents. 

Table 20.8 Usage patterns for polycarbonates and polycarbonate/ABS alloys in Western Europe and the USA 1997. (Based on information published in Modern Plastics International)...

Hollomon s ethos, combined with his ferocious energy and determination, and his sustained determination to recruit only the best researchers to join his group, over the next 15 years led to a sequence of remarkable innovations related to materials, including man-made diamond, high-quality thermal insulation, a vacuum circuit-breaker, products based on etched particle tracks in irradiated solids, polycarbonate plastic and, particularly, the Lucalox alumina envelope for a metal-vapour lamp. (Of course many managers besides Hollomon were involved.) A brilliant, detailed account of these innovations and the arrangements that made them possible was later written by Guy Suits and his successor as director, Arthur Bueche (Suits and Bueche 1967). Some of these specific episodes will feature later in this book, but it helps to reinforce the points made here about Hollomon s coneeption of broad research on materials if I point out that the invention of translucent alumina tubes for lamps was... 

A wide variety of thermoplastics have been used as the base for reinforced plastics. These include polypropylene, nylon, styrene-based materials, thermoplastic polyesters, acetal, polycarbonate, polysulphone, etc. The choice of a reinforced thermoplastic depends on a wide range of factors which includes the nature of the application, the service environment and costs. In many cases conventional thermoplastic processing techniques can be used to produce moulded articles (see Chapter 4). Some typical properties of fibre reinforced nylon are given in Table 3.2. 

To maximize control in setting tolerances there is usually a minimum and a maximum limit on thickness, based on the process to be used such as those in Tables 3-6 to 3-9. Each plastic has its own range that depends on its chemical structure, composition (additives, etc.), and melt-processing characteristics. Any dimensions and tolerances are theoretically possible, but they could result in requiring special processing equipment, which usually becomes expensive. There are of course products that require and use special equipment such as polycarbonate compact discs (CDs) to meet extremely tight tolerances. 

A method of converting polycarbonate (PC) to bishydroxyethyl ether of bisphenol A (BHE-BPA) was studied, with a view to recycling PC plastic wastes. Treating PC in ethylene glycol with a catalytic amount of sodium hydroxide produced the monohydroxyethyl ether of bisphenol A (MHE-BPA, 42%), BHE-BPA (11%) and BPA (42%). BHE-BPA was produced quantitatively when 1.6 mol. equiv. ethylene carbonate was added to this reaction system. The reaction of BPA with EC produced both BHE-BPA and MHE-BPA, indicating that ethylene carbonate was formed as an intermediate in the base catalysed reaction of PC with ethylene glycol. A large proportion of this ethylene carbonate formed from PC was, however, lost by decarboxylation so additional ethylene carbonate must be provided for the quantitative preparation of BHE-BPA. 12 refs. 

Traditionally, ultrafilters have been manufactured from cellulose acetate or cellulose nitrate. Several other materials, such as polyvinyl chloride and polycarbonate, are now also used in membrane manufacture. Such plastic-type membranes exhibit enhanced chemical and physical stability when compared with cellulose-based ultrafiltration membranes. An important prerequisite in manufacturing ultrafilters is that the material utilized exhibits low protein adsorptive properties. 

Moreover, y-P.V.19 is also found in a variety of other media, such as powder coatings and cast resins. This includes systems based on unsaturated polyester resins whose hardening is not affected by the pigment. The list of application media includes plastics which are processed at very high temperature (such as polycarbonates), in which the pigment is thermally stable up to 320°C. PUR foams and... 

Ultrafiltration membranes are usually manufactured from tough plastic-based polymers, such as polyvinyl chloride or polycarbonate. A range of membranes are available which display different cut-off points (Figure 3.20). Membranes displaying cut-off points of 3, 10, 30, 50 and 100 kDa are most commonly used. Thus, if the protein of interest displays a molecular mass of 70kDa, it may be concentrated effectively by using an ultrafilter membrane displaying a molecular mass cut-off point of 50 kDa. Ultrafiltration is a popular method of concentration because ... 

From a practical point of view the purpose of this study was to increase the crystallizability of the polycarbonate by incorporating in it well-defined amounts of plasticizer. With this modification, crystalline polycarbonate films could be made with a higher modulus of elasticity, and these would extend the usefulness of the polymers as photographic film bases. When this study was completed an article was published by Sears and Darby (16), who made an extensive study of the plasticization of polycarbonate using 50 plasticizers of widely differing types. The crystallization tendency in the presence of plasticizers was recognized by these authors as a problem and was circumvented by quench cooling. 

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