Bisphenol blends

Polycarbonates are prepared commercially by two processes Schotten-Baumaim reaction of phosgene (qv) and an aromatic diol in an amine-cataly2ed interfacial condensation reaction or via base-cataly2ed transesterification of a bisphenol with a monomeric carbonate. Important products are also based on polycarbonate in blends with other materials, copolymers, branched resins, flame-retardant compositions, foams (qv), and other materials (see Flame retardants). Polycarbonate is produced globally by several companies. Total manufacture is over 1 million tons aimuaHy. Polycarbonate is also the object of academic research studies, owing to its widespread utiUty and unusual properties. Interest in polycarbonates has steadily increased since 1984. Over 4500 pubflcations and over 9000 patents have appeared on polycarbonate. Japan has issued 5654 polycarbonate patents since 1984 Europe, 1348 United States, 777 Germany, 623 France, 30 and other countries, 231. 

During the eady development of polycarbonates, many bisphenols were investigated for potential useftil products. Some of these monomers and polymers are hsted in Table 3. Despite this intensive search, however, no homopolycarbonates other than that of BPA have been produced. Copolymers and blends, on the other hand, have been quite successhil. Blends of polycarbonate with ABS and with poly(butylene terephthalate) (PBT in particular have shown significant growth since the mid-1980s. 

ABS can be blended with bisphenol A polycarbonate resins to make a material having excellent low temperature toughness. The most important apphcation of this blend is for automotive body panels. 

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). 

McNeill and Basan [151] studied the thermal degradation of blends of PVC with bisphenol-A polycarbonate. The structure of bisphenol-A polycarbonate is given in Eq. (42). 

Birley, A.W. and Chen, X.Y., A preliminary study of blends of bisphenol A polycarbonate and poly (ethylene terephtalate), Brit. Polym. J., 17, 297, 1985. 

Blends of enzymatically synthesized poly(bisphenol-A) and poly(p-r-butylphenol) with poly(e-CL) were examined. FT-IR analysis showed the expected strong intermolecular hydrogen-bonding interaction between the phenolic polymer with poly(e-CL). A single 7 was observed for the blend, and the value increased as a function of the polymer content, indicating their good miscibility in the amorphous state. In the blend of enzymatically synthesized poly(4,4 -oxybisphenol) with poly(e-CL), both polymers were miscible in the amorphous phase also. The crystallinity of poly(e-CL) decreased by poly(4,4 -oxybisphenol). 

Shell s Epon 828, a blend of oligomers of diglycidyl ether of bisphenol A (DGEBA, n=0), was used. 

The most-common polycarbonates are based on bisphenol A (see Figure 4.75) but, more recently, heat resistant grades were launched based on other bisphenols, possibly blended with bisphenol A. 

A mjmber of blends were prepared from a bisbenzocyclobutene monomer (BCB) and various bisdienophiles (Kerimid 353 dicyanates such as bisphenol A dicyanate, tetramethylbisphenol F dicyanate and thiodiphenol dicyanate and bisphenyl-acetylenes ... 

All the materials in this study are commercially available and were used as received. The compositions of the mixtures are given in Table I. The components can be described as follows Resin is a proprietary blend of acrylated epoxy resins with an number average molecular weight (Mn) of "4800, based on acrylated diglycidyl bisphenol A, DGEBAcr is the diacrylate derivative of diglycidyl bisphenol A, IBOA is isobomyl acrylate, TMPTA is trimethyloltriacrylate and DMPA is 2,2-dimethoxy-2-phenyl acetophenone. 

Fei B, Cheng C, Peng SW, Zhao XJ, Wang XH, Dong LS (2004) FTIR study of poly (propylene carbonate)/bisphenol A blends. Polym bit 53 2092-2098... 

Crystallization behavior in miscible blends containing crystallizable components has been extensively studied [174-180]. Generally, when a crystallizable component is mixed with an amorphous component its melting temperature goes down and its crystallinity lowers. The same trend has been reported for blends with intercomponent hydrogen bonding such as PCL/STVPh [181], PCL/poly(hydroxyl ether of bisphenol A) [182] and phenoxy resin/PEO [183]. 

The blend of poly(bisphenol A carbonate)-(poly(caprolactone) PC-PCL is particularly unusual in that both polymers are capable of crystallization and FT-IR has been used to study the state of order in these blends as a function of the method of preparation 254,255). In this case, PCL is a macromolecular plasticizer for PC. The PCL becomes progressively less crystalline as the concentration of PC increases. PC is amorphous if the blend is cast from methylene chloride but semicrystalline if cast from tetrahydrofuran. When PC in the pure form is exposed to acetone, it will not crystallize, but in the blend, exposure of acetone causes the PC to crystallize which emphasizes the additional mobility of the PC in the blend. 

Actually, ABS can be considered as an impact modifier for PC. PC/ABS blends have been compatibilized with both maleic anhydride (MA)-grafted poly(propylene) (PP) and a solid epoxy resin of the bisphenol A type. Both compatibilizers are effective for formulations of an ABS content up to 30%. The the impact strength of the compatibilized blends was close to that of PC. However, above 40% ABS content, the impact strength decreases significantly (19). 

K.H. Pawlowski, B. Schartel, M.A. Fichera, and C. Jager, Flame retar-dancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol a polycarbonate/acrylonitri-le-butadiene-styrene blends, Thermochim. Acta, In Press, Accepted Manuscript, 2009. 

Radel A 400 polyarylsulfone resin is made from a proprietary blend of bisphenols (believed to include hydroquinone) and dichlorodiphenyl sulfone. Victrex resin is made by other displacement reactions. 

Carboxylated polyesters were prepared by extending hydroxyl-terminated polyester segments with dianhydrides. Carboxylated polyesters which were soluble in common lacquer solvents were effective in improving the adhesion of coatings on a variety of substrates when 1-10% was blended with cellulose acetate butyrate, poly(vinyl chloride), poly(methyl methacrylate), polystyrene, bisphenol polycarbonates, and other soluble polymers. 

In order to investigate the molecular motions involved in this transition and, in particular, the nature of the associated cooperativity, it is interesting to consider not only BPA-PC, but also tetramethyl bisphenol A polycarbonate, TMBPA-PC, (Fig. 25) as well as copolymers of BPA and TMBPA carbonates, and compatible blends of BPA-PC and TMBPA-PC. 

Figure 8.2 Schematic phase diagrams for thermoplastic-epoxy monomer (diglycidyl ether of bisphenol A) blends, (CPC = cloud point curve, and VC = vitrification curve), (a) and (b) UCST (upper critical solution temperature) behaviour for PPE and PEI (respectively) - DGEBA n = 0.15 (c) LCST (lower critical solution temperature) behaviour for PES-DGEBA y n = 0.15. (Pascault and Williams, 2000 - Copyright 2001. Reprinted by permission of John Wiley Sons Inc.)...

More recently, Weider et al. [143] prepared polycarbonates starting from chlorinated rubbers. The diacids obtained after ozonization of these polymers are reacted with phosgene and Bisphenol A to give a polycarbonate used as additive in commercial polycarbonate or in blends of polycarbonate with polyisobutylene. 

Blending of polymers is an attractive method of producing new materials with better properties. Blends of aliphatic polyesters, especially of poly(e-CL), have been investigated extensively and have been the subject of a recent review paper [170]. Poly(e-CL) has been reported to be miscible with several polymers such as PVC, chlorinated polyethylene, SAN, bisphenol A polycarbonate, random copolymers of Vdc and VC, Vdc and AN, and Vdc/VAc, etc. A single composition-dependent Tg was obtained in the blends of each of these polymers with poly(e-CL). This is of interest as a polymeric plasticizer in these polymers. Blends of PVC and poly(e-CL) with less than 50 wt % of poly(e-CL) were homogeneous and exhibited a single Tg. These blends were soft and pliable because the inherent crystallinity of poly(e-CL) was destroyed and PVC was plasticized... 

Continuity can also be reached by polymerizing one of the components within the other. In such a case the blend is called an IPN, an interpenetrating network it is, in most cases formed by a thermoset in a thermoplastic polymer. An example is a compound built-up from 50% of a thermoplast (polycarbonate or polysulphone), and 50% of a cross-linked polymer on the basis of dicyanate bisphenol-A. The skeleton... 

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