Polycarbonates polyester carbonates

Color/Transparency. Almost all amorphous engineering thermoplastics, except PC and some polyester carbonates, are inherently colored. Even polycarbonates have yellowness indexes (YI) (36) of 0.1 to 5.0. Colorless material is produced from these resins by compounding with complementary blue dyes which reduce transmission. Ha2e in amorphous resins is an indication of particulates. Ha2e reduces optical clarity and transmission. 

Polycarbonate (PC) Resins. Polycarbonates (qv) based on bisphenol A are sold in large quantities. Other bisphenols can be incorporated, but do not give the same favorable combination of properties and cost (82). Small quantities of PC based on tetramethylbisphenol A are used as blending resins (83) and polyester carbonate copolymers are used for appHcations requiring heat-deflection temperatures above those of standard PC resins (47). 

Today about 75% of the market is held by General Electric and Bayer with their products Lexan and Makrolon respectively. Other manufacturers are ANIC (Italy), Taijin Chemical Co., Mitsubishi Edogawa and Idemitsu Kasei in Japan and, since 1985, Dow (USA) and Policarbonatos do Brasil (Brazil). Whilst this market is dominated by bis-phenol A polycarbonates, recent important developments include alloys with other thermoplastics, polyester carbonates and silicone-polycarbonate block copolymers. 

In the 1980s a number of copolymers became established, known as polyester carbonates, which may be considered as being intermediate between bisphenol A polycarbonates and the polyarylates discussed in Chapter 25. 

See also PBT degradation structure and properties of, 44-46 synthesis of, 106, 191 Polycaprolactam (PCA), 530, 541 Poly(e-caprolactone) (CAPA, PCL), 28, 42, 86. See also PCL degradation OH-terminated, 98-99 Polycaprolactones, 213 Poly(carbo[dimethyl]silane)s, 450, 451 Polycarbonate glycols, 207 Polycarbonate-polysulfone block copolymer, 360 Polycarbonates, 213 chemical structure of, 5 Polycarbosilanes, 450-456 Poly(chlorocarbosilanes), 454 Polycondensations, 57, 100 Poly(l,4-cyclohexylenedimethylene terephthalate) (PCT), 25 Polydimethyl siloxanes, 4 Poly(dioxanone) (PDO), 27 Poly (4,4 -dipheny lpheny lpho sphine oxide) (PAPO), 347 Polydispersity, 57 Polydispersity index, 444 Poly(D-lactic acid) (PDLA), 41 Poly(DL-lactic acid) (PDLLA), 42 Polyester amides, 18 Polyester-based networks, 58-60 Polyester carbonates, 18 Polyester-ether block copolymers, 20 Polyester-ethers, 26... 

Polyester-6/oe/ -polycarbonate, 7 646 Polyester bottles, recycling, 20 54-56 Polyester can coatings, 13 39 Polyester carbonates, 19 822 Polyester-carboxyl powder coatings 1998 production, 7 49 Polyester composites, cross-linked, 20 114 Polyester composition, determining, 20 21 Polyester diols, 25 476... 

Japan s Mitsubishi Gas Chemical (MGC) also offers a biodegradable version of polycarbonate termed polyester carbonate (PEC). It has a melting point of 110 °C and stiffness-toughness balance comparable to PP homopolymer. MGC s PEC reportedly is used in a new portable tape-cassette player introduced by Sony Corp. 

Sinicropi et al. (1996a) measured hole mobilities of ENA-B doped into a series of polymers poly(styrene) (P-1), bisphenol-A polycarbonate (P-2), pofy(4,4 -isopropylidene bisphenylene-co-4,4 -hexafluoroisopropylidene)bis-phenylene (50/50) terephthalate-co-azelate (65/35) (P-3), poly(4,4 -(2-norbotyli-dene)diphenylene terephthalate-co-azelate (40/60) (P-4), a phosgene-based polyester carbonate (P-5), and poly(vinyl butyral) (P-6). The ENA-B concentrations were 45%. Figure 64 shows the room temperature field dependencies. The mobilities vary by over four orders of magnitude. The field and temperature dependencies were described as log/i fiEl/2 and -(TJT)2. Table S summarizes the results. 

Aliphatic polycarbonates (polyesters of carbonic acid) are obtained by the transesterification reaction of dialkyl carbonates (for example dimethyl carbonate) with aliphatic diols. A typical example is the polycondensation of dimethyl carbonate with 1,6 hexanediol (reaction 8.3) [4-8] ... 

Xenoy DX6302 Polycarbonate/polyester alloy with carbon fiber GE Plastics... 

Phase-separated PEI blends have been investigated. Combinations of PEI with polycarbonate (PC) or polycarbonate ester (PCE) copolymers have a fine, laminar two-phase morphology [36]. Combinations of PEI with polycarbonate or polyester carbonates yield a family of two-phase opaque systems that have reduced heat capability versus PEI, but show improved impact and better melt flow [37, 38]. 

In applications requiring higher thermal performance, a polyester-carbonate copolymer has been developed with an HDT that is 28°C (50°F) higher than that of standard polycarbonate homopolymers (see the section Polyestercarbonates and Other High-Heat Polycarbonates ). The most common use of this material occurs in automotive headlamp applications, where the copolymer forms the metallized reflector, and in animal cages that require repeated autoclave sterilization. 

The chemical resistance of polyarylates (polyester carbonate) is largely similar to that of polycarbonate, but their ester content causes a more favorable behavior in hydrocarbons and boiling water. Figure 5.342. They are resistant to dilute mineral acids and acidic and neutral aqueous salt solutions. Bases, aqueous solutions of ammonia, amines, and alkaline salt solutions destroy polyarylates by hydrolytic degradation. Polyarylates are not attacked by aliphatic hydrocarbons and alcohols with the exception of methyl alcohol they are swelled and often dissolved by aromatics, ketones, esters, and halogenated hydrocarbons [723]. 

Ethylene-Propylene-Diene Terpolymer (EPDM) is used for weather protection, tire sidewalls and coverstrips, wire, cable, mechanical goods, sheeting, hoses, tubing, and plastics modification and TPO. EPDM can be modified with silicone to reinforce high temperature performance of silicone and mechanical and physical strength of EPDM. Maleated EPDM (0.5 to 1.0%) is used to toughen nylon (impact modifier of nylon) and polyester thermoplastics (impact modifier for polycarbonate and polyester/carbonate alloys, PVC). Typical EPDM recipes are... 

Heitz synthesized polymers with two phenolic end groups by carrying out the polymerization in the presence of a biphenol. Block polyether-polycarbonate and polyether-polyester carbonates were synthesized from these blocks. Percec also prepared a bifunctional PPO by polymerization of 2,6-dimethylphenol in the presence of 2,2 -di(4-hydroxyphenyl-3, 5-dimethylpropane). Etherification of the blocks with chloromethylstyrene gave reactive oligomers that were cross-linkable. When monofunctional PPO was reacted with chloromethyl styrene the resulting styryl-substituted polymers formed comb-like structures on polymerization and could be copolymerized with vinyl monomers. Alternatively, Meijer was able to coredistribute phenol-terminated polymers with PPO to produce block copolymers. ... 

Polycarbonate is a polyester in which dihydric (or polyhydric) phenols are joined through carbonate linkages. The general-purpose type of polycarbonate is based on 2,2-bis(4 -hydroxybenzene)propane (bisphenol A) and has the general structure ... 

---