Acrylic catalysts, crosslinkers

Heterogenization of catalytic nanoparticles stabilized by block copolymers can be carried out by their incorporahon into porous membranes based on poly(acrylic acid) crosslinked with a difunctional epoxide [20-22]. Membranes with defined porosities and amounts of palladium were studied in the selective hydrogenahon of propyne to propene as a model reaction. The porosity of the polymer membrane, the content of catalyst, and the residence time of the reaction mixture were found to influence the conversion and selectivity. The main advantage of these membranes compared to other heterogeneous catalysts is simple adjustment to reaction conditions and fadhtated mass transfer. 

Storage May develop pressure vent bottle periodically Uses Polymerization initiator/catalyst/crosslinking agent for cure of unsaturated polyester resins in gel coats to eliminate or reduce porosity mfg. of acrylic resins hardener for fiberglass-reinforced plastics catalyst in food-contact crosslinked polyesters Regulatory FDA 21 CFR 177.2420... 

Uses Catalyst/initiator for polymerization and for cure of acrylic syrup crosslinking agent for high-temp, cure of unsat. polyester resins... 

Uses Catalyst, crosslinking agent for heated curing of unsat. polyester resin systems polymerization initiator for acrylates, PE, PS Trade Name Synonyms Aztec DHPEH f[Aztec Peroxides] Trigonox 141 f[Akzo Nobel http //www.akzonobel.com], USP -245 t[Crom pto n http //www. cromptoncorp. com]... 

A new transesterification stanoxane catalyst, tin (di(chlorodimethylsiloxy)-tin chlor-odimethylsilane), has been used to incorporate ethyl acrylate into the condensation polymer of 2,2-bis(hydroxymethyl)propionic acid. This catalyst is preferable because it allows the reaction to proceed under milder conditions than those using a condensation esterification reaction route and makes it likely for product crosslinking side reactions to occur. 

Resins with good hydrodynamic properties and sorption capadties for proteins and enzymes have been prepared by the polymerization of acrylic acid or methacrylic acid and a crosslinking monomer such as 1,3,5-triacryloylhexahydrotriazine (TAT) in aqueous acetic acid using a radical initiator. Methacrylic add-TAT copolymer prqjared by using a redox catalyst is useful as a cation-exchange resin for selective and reversible sorption of proteolytic enzymes such as terrilytin. 

A range of self crosslinking formaldehyde free acrylic resins which impart different degrees of stiffness and improve fabric stability. Cured in a relatively short time above 150C to a wash resistant finish without catalyst. 

Materials. The polyurethane precursor materials were Adiprene L-lOO (Uniroyal, Inc.), a poly(oxytetramethylene glycol) capped with toluene diisocyanate, eq. mol. wt. 1030 1,4-butanediol (BD) and 1,1,1-trimethylolpropane (TMP) and, as catalyst, dibutyltin dilaurate (DBTDL). Acrylic precursors included n-butyl methacrylate (BMA), washed with 10% aq. NaOH to remove inhibitor tetramethylene glycol dimethacrylate (TMGDM) crosslinker and benzoin sec-butyl ether (BBE) as a photosensitizer. These materials were dried appropriately but not otherwise purified. 

Typical resists include cyclized polyisoprene with a photosensitive crosslinking agent (ex bisazide) used in many negative photoresists, novolac resins with diazoquinone sensitizers and imidazole catalysts for positive photoresists, poly(oxystyrenes) with photosensitizers for UV resists, polysilanes for UV and X-ray resists, and polymethacrylates and methacrylate-styrenes for electron-beam resists (Clegg and Collyer, 1991). Also note the more recent use of novolac/diazonaphthoquinone photoresists for mid-UV resists for DRAM memory chips and chemically amplified photoacid-catalysed hydroxystyrene and acrylic resists for deep-UV lithography (Choudhury, 1997). 

Uses Blocked catalyst for use in isocyanate-crosslinked polyols like solv.-based and aq. hydroxy acrylates and polyesters, e.g., forced drying two-pack lacquers... 

Chem. Descrip. Catalyst in butyl acetate/polyglycol Uses Catalyst reducing drying time in solv.-based and aq. isocyanate-crosslinked polyols, hydroxy acrylates, and polyesters, lacquers Properties YIsh. clear to si. turbid liq. vise. < 20 mPa s (20 C) flash pt. 34 C 30% act. 

Empirical C14H28O4 Properties M.w. 260.37 Uses Crosslinking agent for polymerization, cure of acrylic syrup catalyst for vinyl polymerization 1,1-Dimethyl-3-... 

Release force measurements were carried out after mixing the equilibration product with an a,co-divinyl(polydimethylsiloxane) at the desired ratio of SiH/vinyl and 100 ppm of platinum as a 1 % Karstedt catalyst solution in poly(dimethylsiloxane). The crosslinker thereby obtained was coated onto paper. Acrylate- (A7475, Beiersdorf) and rubber- (RP51, Raflatec) based adhesive tapes were stuck on the paper inline (inunediately after coating) and offline (after four weeks) and release force measurements were carried out at a speed of 0.3 m/min. 

A unique isocyano-functionalized polymer reported by Hertler was made by reacting 6-hydroxyhexy1 isocyanide with lEM-containing acrylic or styrenic copolymers. These polymers can be formulated with trialkyIborane crosslinkers (17) or Ni salt oligomerization catalysts (18) to give room-temperature cured enamels. 

A typical composition for BMC and SMC includes base resins, catalysts, peroxides accelerators, fillers/chopped GF, thickeners and other additives. The base resins that are usually used are either polyester-based (orthophthalic or isophthalic), which are used with styrene, acrylic, vinyl toluene or di-allyl-phthalate (DAP) monomers, as crosslinkers, or styrene type monomers for general purpose products. Acrylic base resins are used for low shrinkage, while vinyl type monomers for high hot strengths (heat deflection temperatures). Catalysts are used for polyester type resins. Peroxides, such as benzoyl peroxide (BPO) and butyl perbenzoate are used as high temperature catalysts. 

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