Polyester-modified polysiloxanes

The most common polyester-modified polysiloxanes [61] that are used in the coatings industry contain a polyester based on e-caprolactone. It is polymerized on a hydroxy functional polydimethylsiloxane with 7-50 silox-ane units and 1-8 hydorxyl groups. The structural diversity of the siloxane backbone is the same as described for the polyether-modified siloxanes. 

Chem. Descrip. Sol n. of a polyester modified methylalkyl polysiloxane copolymer in Stod./methoxypropyl acetate (9/1)... 

Siloxane containing interpenetrating networks (IPN) have also been synthesized and some properties were reported 59,354 356>. However, they have not received much attention. Preparation and characterization of IPNs based on PDMS-polystyrene 354), PDMS-poly(methyl methacrylate) 354), polysiloxane-epoxy systems 355) and PDMS-polyurethane 356) were described. These materials all displayed two-phase morphologies, but only minor improvements were obtained over the physical and mechanical properties of the parent materials. This may be due to the difficulties encountered in controlling the structure and morphology of these IPN systems. Siloxane modified polyamide, polyester, polyolefin and various polyurethane based IPN materials are commercially available 59). Incorporation of siloxanes into these systems was reported to increase the hydrolytic stability, surface release, electrical properties of the base polymers and also to reduce the surface wear and friction due to the lubricating action of PDMS chains 59). 

Uses Reducing agent in redox-catalyzed polymerization color stabilizer, modifier, catalyst for polyamides antioxidant intermediate for forming metallic salts used as stabilizers accelerator for org. peroxide catalysts improver of polysiloxane resins free radical promoter in emulsion polymerization promoter in polyester resin curing mfg. of self-extinguishing fibers (reacts with polyester resin and polyolefin) color/odor inhibitor, catalyst for some thermoplastics discoloration inhibitor in PE corrosion inhibitor on thin aluminum surfs. lubricity improver in polyphenyl thioether-based lubricants Manuf./Distrib. Akzo Nobel http //www.akzonobel.com, Ferro http //WWW. ferro. com... 

Polycarbonate, PC. PC was introduced in 1958. To improve its processability, impact behavior, and solvent resistance, PC must be modified. The first blends with polyolefins, PO, or with ABS were developed in 1960. These were rapidly followed by alloys with polysiloxanes in 1961, PAES in 1965, PET in 1966, POM in 1968, PSF -n ABS in 1969, PES -n ABS in 1970, PBT in 1971, PA or PPE + SBR in 1973, PPS in 1974, PS in 1976, styrene-maleimide (SMI) in 1977, polyaramid (PARA) in 1979, etc. Owing to the chemical nature of the statistical segment, PC can be readily compatibilized or modified, becoming a frequent component of polymer blends. Its affinity to acrylates has been widely explored. However, only in 1986 was its miscibility with polymethylmethacrylate, PMMA, disclosed [Kambour, 1986]. These blends were found to be suitable for glazing materials and optical disks. Another miscible blend of PC (with aliphatic polyester of neopentyl glycol) was discovered in 1991 [Lundy et al., 1991]. Commercial PC/PA blends are relatively recent. In 1992 Toray Industries introduced Toray-PC and Rohm Haas Paraloid. Both blends contain about 30 % of PARA and PA, respectively. 

The maleic anhydride polymers have been further reacted with epoxides to give epoxide-functionalized PPO that can react with polyesters and give graft copolymers useful for compatibilization of PPO with the polyesters.Reaction of PPO with graftable ortho esters in the melt gives graft polymers that are useful as compatibilizers of PPO with polyesters. The modified PPO has also been reacted with amino-terminated polysiloxanes to produce block copolymers. ... 

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