Thermoplastics resins weathering

Further, methods for producing a thermoplastic resin with good physical properties and appearance properties and weatherability as well, use a three component blend of ASA, PMMA, and polycarbonate) (20). 

Such thermoplastic resin compositions have excellent basic physical properties, weatherability and good appearance properties, such as scratch resistance, color stability and gloss. 

Definition Thermoplastic resin derived from bisphenol A and phosgene or diphenyl carbonate nonconosive resist, to weather, ozone, heat high impact str. high dielec, str. dimensionally stable stable to min. acids poor solv. resist. 

Term associated with plastics having medium to high physical properties used for structural and demanding applications. Five types of resins belong to this group PA, PEST (viz., PBT, PET, PAr), PC, PPE, and POM. The susceptibility of a thermoplastic resin to crack or craze when in the presence of surface-active agents or other environments, e.g., under the influence of certain chemicals or aging, weather, and stress. 

Miyata (694) has shown that as little as 0.05-1% well-crystallized LDH improves the thermal stability and weather resistance of thermoplastic resins containing halogen and/or acidic components from the manufacturing process. 

Thermoplastic resins formed by the acid condensation of formaldehyde and aniline are of importance because of theh excellent electric resistance and low power factor. They ai-e reddish-bro sm in color, have good stnic-tural strength, and are not appreciably affected by exposure to weather or ultra. olet. light. They are used extensively for insulators and other electric equipment. Structurally they are stated to consist of the cyclic anhydi-oformaldehyde aniline, (C6HaN CH2)s, and products produced by nuclear linking of two or more molecules of this compound by means of methylene groups. 

Other fluorine-containing plastics These materials, in general, attempt to compromise between the exceptional end-use properties of p.t.f.e. and the processability of ordinary thermoplastics. Examples include polychlor-trifluorethylene, tetrafluorethylene-hexafluorpropylene copolymers (FEP resins) and polyvinylidene fluoride. Polyvinyl fluoride is available in film form (Tedlar) with excellent weathering resistance. 

Engineering resins are polymers that have outstanding physical properties such as thermal stability, chemical resistance, self-lubrication, weather resistance, etc. Generally, they are thermoplastics. They are gaining in importance in automobile manufacture as metal replacements to provide lighter weight cars. 

Polyester polyols, 25 464 468 Polyester resin(s), 11 302 coating resins, 7 104-106 cyclopentadiene and dicyclopentadiene applications, 8 230 flammability of, 20 115-116 properties in powder coating, 7 43t standard test methods for, 20 11 It unreinforced, 10 187t weathering of, 20 116 Polyester resin-based powder coatings, organic titanium compounds in, 25 125 Polyester resin composites, 26 762-763 Polyester resin formulations ingredients of, 20 96t unsaturated, 15 511-512 Polyesters, 10 185-189, 497 12 655-656. See also Thermoplastic polyesters Unsaturated polyesters acid resistance of, 20 7-8 antioxidant applications, 3 121 aromatic ionic, 23 722 based on 1,4-cyclohexanedimethanol, 12 674-675... 

Polysulfide resins combine with epoxy resins to provide adhesives and sealants with excellent flexibility and chemical resistance. These adhesives bond well to many different substrates. Tensile shear strength and elevated-temperature properties are low. However, resistance to peel forces and low temperatures is very good. Epoxy polysulfides have good adhesive properties down to -100°C, and they stay flexible to -65°C. The maximum service temperature is about 50 to 85°C depending on the epoxy concentration in the formulation. Temperature resistance increases with the epoxy content of the system. Resistance to solvents, oil and grease, and exterior weathering and aging is superior to that of most thermoplastic elastomers. 

In the photoageing of polycarbonates, photo-oxidation has been shown to be a more important process than the photo-Fries reaction. The photo-oxidation of epoxy-resins has been found to depend on the type of hardener and its concentration. A correlation has been observed between the changes in chemical structure and thermally stimulated current of poly(vinyl alcohol) during photo-oxidation. Other studies of interest include the weathering of polymers outdoors,effect of ozonation on polymers, effect of drawing, effect of biodegradation, and changes in mechanical properties of thermoplastics. ... 

Bituminous materials are dark brown or black, semi-solid or liquid, thermoplastic mixtures of hydrocarbons derived from natural or synthetic processes in which hydrocarbon mixtures have lost their volatile components leaving a denser residue. Natural bitumens come from exposed and weathered petroleum and rock deposits. Synthetic bitumens come from the residue remaining after the distillation of petroleum, coal tar, and other organic materials like wood and peat. The complexity of the high molecular weight hydrocarbon oils and resins bitumens contain make complete chemical characterization impossible. The terms bitumen, tar (8007-45-2), pitch (61789-60-4), and asphalt (8052-42-4) apply to any of these substances, although pitch and tar also describe the sticky resins that exude from various trees. 

Coatings with Thermoplastic Fluoropolymers. Poly(vinylidene fluoride), PVDF, is the only conventional thermoplastic fluoropolymer that is used as a commercial product for weather-resistant paints. This crystalline polymer is composed of -CHjCFj- repeating units it is soluble in highly polar solvents such as dimethyl-formamide or dimethylacetamide. Poly(vinylidene fluoride) is usually blended with 20 30 wt% of an acrylic resin such as poly(methyl methacrylate) to improve melt flow behavior at the baking temperature and substrate adhesion. The blended polymer is dispersed in a latent solvent (e.g., isophorone, propylene carbonate, dimethyl phthalate). The dispersion is applied to a substrate and baked at ca. 300 °C for ca. 40-70 s. The weather resistance of the paints exceeds 20 years [2.16]-[2.18]. 

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