Styrenated Polyesters

Other common radical-initiated polymer processes include curing of resins, eg, unsaturated polyester—styrene blends curing of mbber grafting of vinyl monomers onto polymer backbones and telomerizations. 

Organic peroxides are used in the polymer industry as thermal sources of free radicals. They are used primarily to initiate the polymerisation and copolymerisation of vinyl and diene monomers, eg, ethylene, vinyl chloride, styrene, acryUc acid and esters, methacrylic acid and esters, vinyl acetate, acrylonitrile, and butadiene (see Initiators). They ate also used to cute or cross-link resins, eg, unsaturated polyester—styrene blends, thermoplastics such as polyethylene, elastomers such as ethylene—propylene copolymers and terpolymers and ethylene—vinyl acetate copolymer, and mbbets such as siUcone mbbet and styrene-butadiene mbbet. 

Type Olefinic Polyurethane Polyester Styrenic Polyamide... 

Photocuring of commercial unsaturated polyester-styrene mixture was effectively done in the presence of the VOL2CI photoinitiator complex. The chlorine atom produced by the scission of V—Cl bond in the VOL2CI complex is proven to be the initiating species for the photocuring process 168]. 

Uses. There are about forty to fifty organic peroxides commercially available in more than seventy formulations designed for specific applications which include (1) initiators for vinyl monomer polymerizations, and copolymerizations of monomers such as vinyl chloride, ethylene, styrene, vinyl acetate, acrylics, fluoroolefms and buta-dienestyrene (2) curing agents for thermoset polyesters, styrenated alkyds and oils, silicone rubbers and poly allyl diglycol carbonates ... 

Preparation and Cure of Unsaturated Polyester/Styrene Resin... 

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... 

Glass fibres dominate this field either as long continuous fibres (several centimetres long), which are hand-laid with the thermoset precursors, e.g., phenolics, epoxy, polyester, styrenics, and finally cured (often called fibre glass reinforcement plastic or polymer (FRP)). With thermoplastic polymers, e.g., PP, short fibres (less than 1 mm) are used. During processing with an extruder, these short fibres orient in the extrusion/draw direction giving anisotropic behaviour (properties perpendicular to the fibre direction are weaker). 

The unsaturated polyester-styrene combination, is used as the resin matrix, in Fibre-reinforced plastics (FRP) structures. These resins also find use as decorative coatings. 

Bisphenols is a broad term that includes many chemicals with the common chemical structure of two phenolic rings joined together by a bridging carbon. Bisphenol A is a monomer widely used in the manufacture of epoxy and phenolic resins, polycarbonates, polyacrylates and corrosion-resistant unsaturated polyester-styrene resins. It can be found in a diverse range of products, including the interior coatings of food cans and filters, water containers, dental composites and sealants. [4]. BPA and BP-5 were selected for testing by the whole... 

RDX, HMX, TNT, HNIW, AP, AN GAP-THF, BAMO-AMMO, BAMO-NIMO Nylon, Viton, polyester-styrene, HTPB, polyurethane, silicone resin fluoronitropolymer, TEGDN Al, Mg, Mg-Na alloy, B, Zr... 

The bulk of polyester production in the United States has gone to the synthetic coatings field in the manufacture of glyptal resin coatings and varnishes, with production between 200,000,000 and 300,000,000 pounds in the postwar years. A recent development has been the use of polyester-styrene copolymers reinforced by Fiberglas for the manufacture of items such as low-pressure molded boats, corrugated structural sheet, and plastic pipe. The 1947 requirements for glycerol in the production of polyester resins and... 

Dekker and Zimmerman [24] described a cast ammonium nitrate propellant containing polyester styrene-methyl acrylate binder. 

In mixtures with copolymer polyester-styrene the temperature of the oxidant is 582°K and that of copolymer 1020°K. 

Andersen et al. obtained a similar result for mixtures of ammonium nitrate with copolymer polyester-styrene-acrylate and with copolymer butadiene-styrene. 

Zinc Nitrate. See in Vol 8, N40-L and the following Addnl Refs 1) G.W. Batchelder G.A. Zimmerman, Smokeless Propellant Compositions Containing a Polyester Resin , USP 3653993 (1972) CA 79,77449 (1973) [The inventors claim that Zn nitrate acts as the burning rate catalyst in their propint formulation. Thus, the addn of 0.1% Zn nitrate to a propint contg AN (45), amm dichromate (5%), a polyester, styrene, methacrylate and lecithin increased this parameter from 0.07 to 0.11 indies/ sec] 2) Anon, Fire Protection. . . 7th Edition , NFPA, Boston (1979), 491M-445 [This source reports that Zn nitrate will expld if sprinkled on hot C. Also, that heat, shock and friction sensitive expls are formed when the nitrate is intimately mixed with the following finely divided materials Cu, metal sulfides, organic matter, P and S]... 

PES = Polyester-styrene copolymer NG = Nitroglycerine PS NGU - Polystyrene plasticizer with dioctylphthalate = Nitroguanidine PU = Polyurethane NC = Nitrocellulose ... 

The solution of the precursors of the thermosetting polymer (mixture of monomers or oligomers with or without initiators, catalysts and different additives) is usually a liquid at room temperature e.g., unsaturated polyester styrene, some epoxy anhydride and epoxy amine formulations, cya-nate esters, one-stage phenolics, etc. Cooling any of these solutions below room temperature leads to a glass. The temperature at which the glass-liquid transition of the initial formulation takes place is denoted as Tg0. Some other particular formulations, such as two-stage phenolics (novo-lac-hexa mixtures), some epoxy-amine systems, etc., exhibit a Tg0 above room temperature. 

Let us consider the variation of the composition in a two-component system (R + H), e.g., unsaturated polyester-styrene or epoxide-amine. Are density measurements capable of detecting such a variation ... 

Among the emerging pollutants of industrial origin, Bisphenol A [2,2 bis(4-hydroxydiphenyl)pro-pane] (BPA) has special relevance since it was one of the first chemicals discovered to mimic estrogens as endocrine disrupters.147 This compound was first reported by Dianin in 1891.1411 BPA is produced in large quantities worldwide, mainly for the preparation of polycarbonates, epoxy resins, and unsaturated polyester-styrene resins.149 The final products are used in many ways, such as coatings on cans, powder paints, additives in thermal paper, in dental composite fillings, and even as antioxidants in plasticizers or polymerization inhibitors in polyvinyl chloride (PVC). To a minor extent, BPA is also used as precursor for flame retardants such as tetrabromobisphenol A or tetrabromobisphenol-S-bis(2,3-dibromopropyl) ether.150 This substance can enter the environment... 

Enolization is catalyzed in acidic polyester styrene solutions, and chelated enol tautomers should be more probable than the keto form in styrene, a nonpolar solvent. The tertiary hydroperoxide intermediates that are proposed by this mechanism should, furthermore, be unstable in an acid medium (8,18). 

The purpose of this work was to correlate catalytic activity with chemical structure for various aromatic and heterocyclic carbonyl compounds. Gel time, gel time as a function of initiator concentration, and gel time as a function of temperature were used to measure catalytic activity for the unsaturated polyester styrene systems used throughout this work. 

Arylcarbonyl Compounds as Initiators for Unsaturated Polyester/ Styrene Copolymerization Systems. Gel Time Determination and Reaction Curves. Ten blanks (gel time of 20 grams Vestopal A without initiator) gave a mean deviation from the average of 3.3% and a maximum deviation of 7.2%. Five measurements with l-phenyl-2-propanone as initiator gave a mean deviation from the average of 3.3% and a maximum deviation of 7.7%. An experimental error of 10% was therefore assumed and proved correct by spot checks. The exceptions (not used in the discussions) are most probably caused by the insolubility of the initiators in the reaction medium. 

The initiator was weighed into a test tube (radius = 10 mm.), 20 grams of fresh (stored at 0°C.) unsaturated polyester/styrene solution (Vestopal A) were added, the mixture was stirred well with a glass rod,... 

It is possible that for a-pyridoin a minimum quantity is enough to start a copolymerization, a sizable excess causing retardation through recombination with the initiator radical. To determine this minimum quantity of initiator, the concentration was lowered to 2.75 X 10 4 mole/liter polyester (1 mg. per 20 grams polyester-styrene solution = 0.005 wt. %) the same gel time of 3.6 minutes was obtained (Table VII). The gel time rose, however, to 26 minutes when the concentration was lowered to 1.11 X 10 4 mole/liter polyester, 0.4 mg. or 0.002 wt. %. The temperature maxima for all concentrations of this compound at 100°C. did not exceed 102°C. 

Property PE ppi PS Nylon PP 50% PE 43% Nylon 7% Polyester styrene copolymer... 

Thermoset plastics have also been pyrolysed with a view to obtain chemicals for recycling into the petrochemical industry. Pyrolysis of a polyester/styrene copolymer resin composite produced a wax which consisted of 96 wt% of phthalic anhydride and an oil composed of 26 wt% styrene. The phthalic anhydride is used as a modifying agent in polyester resin manufacture and can also be used as a cross-linking agent for epoxy resins. Phthalic anhydride is a characteristic early degradation product of unsaturated thermoset polyesters derived from orf/io-phthalic acid [56, 57]. Kaminsky et al. [9] investigated the pyrolysis of polyester at 768°C in a fiuidized-bed reactor and reported 18.1 wt% conversion to benzene. 

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