Thermosetting styrene resin

A number of thermosetting acrylic resins for use as surface coatings have appeared during recent years. These are generally complex copolymers and terpolymers such as a styrene-ethyl acrylate-alkoxy methyl acrylamide... 

Unsaturated polyesters (UPs), 4, 18, 19 from PET waste, 560-561 Unsaturated polyester/styrene resin, preparation and cure of, 101 Unsaturated polyester thermosetting resins, syntheses of, 101-103 Unstirred interfacial process, 155 U-Polymer, 77... 

Benzoyl peroxide is used as a source of free radicals in many organic syntheses and to initiate polymerizations of styrene, vinyl chloride, vinyl acetate, and acrylics to cure thermoset polyester resins and silicone rubbers in medicine for treating acne and for bleaching vegetable oil, cheese, flour, and fats. 

The search for materials to aid in the defense effort during World War II resulted in a profound impetus for research into new plastics. Polyethylene, now one of the most important plastics in the world, was developed because of the wartime need for better-quality insulating materials for such applications as radar cable. Thermosetting polyester resins (now used for boatbuilding) were developed for military use. The terpolymer acrylonitrile-butadiene-styrene (ABS), (telephone handsets, luggage. 

Diplast D Diplast 0 Diplast R Diplast TM Diplast TM8 Lexorez 1100-220 Trioctyl trimellltate veNde, pigment grinding Beetle 227-8 Polyester resin, thermosetting, Styrene/acrylates copolymer... 

Thermosetting acrylic resins are used widely in surface coatings. Both acrylic and methacrylic esters are utilized and the term is applied to both of them. Often, such resins are terpolymers or even tetrapolymers, where each monomer is chosen for a special function. One is selected for rigidity, surface hardness, and scratch resistance another for ability to flexibilize the film, and the third for crosslinking it. In addition, not all comonomers are necessarily acrylic or methacrylic esters or acids. For instance, among the monomers that may be chosen for rigidity may be methyl methacrylate. On the other hand, it may be styrene instead, or vinyl toluene, etc. The same is true of the other components. Table 5.12 illustrates some common components that can be found in thermoset acrylic resins. 

Ethenoid plastics n. (1) Plastics made from monomers containing the polymerizable double-bond group C=C, for example ethylene. Thermosetting ethenoid resins are made from monomers for linear polymers capable of giving crosslinked structures as a result of double-bond polymerization. (2) A British generic term that includes acrylic, vinyl, and styrene plastics. 

Hexabromobiphenyl - bro-(i)mo-(i)bl- fe-n l n. [2,4,6-(Br)3C6H2-]2- A flame retardant suitable for use in thermosetting resins and thermoplastics such as acrylo-nitrile-butadiene-styrene resin, nylons, polycarbonate, polyolefins, PVC, polyphenylene oxide, and polystyrene-acrylonitrile. It is insoluble in water, heat-stable, and furnishes a high bromine content in the end product. 

Polyester Resins. Reinforced polyester resins are thermosets based on unsaturated polyesters from glycols and dibasic acids, either or both of which contain reactive double bonds. The ratio of saturated to unsaturated components controls the degree of cross-linking and thus the rigidity of the product (see Polyesters, unsaturated). Typically, the glycols and acids are esterified until a viscous Hquid results, to which an inhibitor is added to prevent premature gelation. Addition of the monomer, usually styrene, reduces the viscosity to an easily workable level. 

The thermoplastic or thermoset nature of the resin in the colorant—resin matrix is also important. For thermoplastics, the polymerisation reaction is completed, the materials are processed at or close to their melting points, and scrap may be reground and remolded, eg, polyethylene, propjiene, poly(vinyl chloride), acetal resins (qv), acryhcs, ABS, nylons, ceUulosics, and polystyrene (see Olefin polymers Vinyl polymers Acrylic ester polymers Polyamides Cellulose ESTERS Styrene polymers). In the case of thermoset resins, the chemical reaction is only partially complete when the colorants are added and is concluded when the resin is molded. The result is a nonmeltable cross-linked resin that caimot be reworked, eg, epoxy resins (qv), urea—formaldehyde, melamine—formaldehyde, phenoHcs, and thermoset polyesters (qv) (see Amino resins and plastics Phenolic resins). 

The largest user of phenol in the form of thermosetting resins is the plastics industry. Phenol is also used as a solvent and in the manufacture of intermediates for pesticides, pharmaceuticals, and dyestuffs. Styrene is used in the manufacture of synthetic rubber and polystyrene resins. Phthalic anhydride is used in the manufacture of DMT, alkyd resins, and plasticizers such as phthalates. Maleic anhydride is used in the manufacture of polyesters and, to some extent, for alkyd resins. Minor uses include the manufacture of malathion and soil conditioners. Nitrobenzene is used in the manufacture of aniline, benzidine, and dyestuffs and as a solvent in polishes. Aniline is used in the manufacture of dyes, including azo dyes, and rubber chemicals such as vulcanization accelerators and antioxidants. 

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