Reaction injection molding nylons

Reaction injection molding Nylon, polyurethane (thermoset), epoxy, polyester... 

Reaction Injection Molding. RIM uses the anionic polymeri2ation of nylon-6 to carry out polymeri2ation in the mold. A commercial process involves the production of block copolymers of nylon-6 and a polyether by mixing molten caprolactam, catalyst, and polyether prepolymer, and reacting in a mold (27,28). 

Reaction-Injection Molding and Reactive Casting. Reaction-iajection molding (RIM) (22) and reactive casting (23) have been demonstrated on nylon-6, which is polymerized by catalytic ring opening and linear recondensation of S-caprolactam (qv) (24). 

RCM. See Ring-closing metathesis (RCM) Reaction by-products, removing, 83 Reaction extrusion, 204 Reaction index, 237 Reaction injection molding (RIM), 205 Reaction-in-mold (RIM) nylon, 149 Reaction kinetics, 76, 77 Reaction mechanisms, polyesterification, 66-69... 

Write out the complete reactions for polyurethane production starting with toluene, natural gas, air, water, and salt, as sketched in Figure 11-8. Use 1,4-butane diol for the glycol starting from butane. Why is this process preferable for reaction injection molding of automobile parts compared to Nylon or PET ... 

Nylon-6 can also be produced from molten caprolactam using strong bases as catalysts (anionic polymerization) this is used as the basis of monomer casting and reaction injection molding (RIM). Anionic polymerization proceeds much faster than the hydrolytic route but products retain catalysts which may need to be extracted. 

The successful utilization of Reaction Injection Molding (RIM) to fabricate complex polyurethane shapes In a single step from relatively low viscosity streams has led to a search for other chemical systems which can be fabricated by the RIM process. The rapid polymerization of molten caprolactam by anionic catalysis has been utilized to develop attractive nylon RIM systems. The incorporation of a rubber segment In the polymer chain allows the fabrication of high Impact or even elastomeric nylon parts. The combination of a rubber phase with the high melting (215°C) crystalline nylon phase provides useful properties at low temperatures as well as at elevated temperatures. 

The production of cast mineral-reinforced nylon 6 products was terminated in 1971. Research was then directed at expanding the range of properties obtainable from the anionic polymerization of caprolactam through nylon block copolymers and their fabrication by reaction injection molding. 

Anionic polymerization of nylon-based polymer systems to produce finished parts directly from monomers or prepolymers can be carried out by several processes e.g., reaction injection molding, low-pressure casting, resin transfer molding, rotational casting. 

Quite recently, the activated anionic polymerization of CL has been found suitable for the reaction injection molding (RIM) technology (9-12) and has prompted some new studies (13-15) devoted to update the classical picture of the reaction kinetics (lj>), mostly in terms of potential industrial applications of the RIM process (13-15,17-20). Successful attempts by Hedrick et al. (11,12) to anionically synthesize a series of PCL block copolymers has led to impact-modified RIM nylon... 

The extruder can be used for a variety of polymerizations even if no preformed polymer is present.89 These include the continuous anionic polymerization of caprolactam to produce nylon 6,90 anionic polymerization of capro-lactone 91 anionic polymerization of styrene 92 cationic copolymerization of 1,3-dioxolane and methylal 93 free radical polymerization of methyl methacrylate 94 addition of ammonia to maleic anhydride to form poly(succin-imide) 95 and preparation of an acrylated polyurethane from polycaprolactone, 4,4 -methylenebis(phenyl isocyanate), and 2-hydroxyethyl acrylate.96 The technique of reaction injection molding to prepare molded parts is slightly different. Polyurethanes can be made this way by... 

Additives, nylon RIM (reaction injection molding), plasticizers. stabBiessu. 

Melt processable nylons are needed for the application of this polymer to plastic products. They are fabricated by injection molding, extmsion, rotomolding, and powder coating. Recently, novel fabrication processes accompanying chemical reactions have been developed with significant commercial importance. The reaction injection molding, reactive extmsion, and reactive blending are typical examples. 

N nylon, PO polyolefin, elastomer, TPU thermoplastic urethane, GF glass fiber, NBR nitrile rubber, MAH maleic anhydride, EPR ethylene-propylene copolymer, l ionomer, M- mineral, ABS acrylonitrile-butadiene-styrene copolymer, PPE poly (phenylene ether), R reinforcement, PTFE poly(tetrafluoroethylene), CF° carbon fiber, PEBA poly(etherblockamide), S silicone, RIPP D reaction injection molding plastic, and ASA acrylate-styrene-acrylonitrile copolymer. 

The principal material used for RIM is polyurethane, however nylon, polyethylene, epoxy, and polyester can also be used. Chopped glass fibers and inorganic fillers have been added to these materials to increase strength and stiffness. The process then becomes known as reinforced reaction injection molding (RRIM). 

Competitive penetration of polypropylene into other applications has primarily taken place in polyethylene, polystyrene, polyvinyl chloride (PVC), thermoplastic polyester, nylon-6 or -6/6, and sometimes directly from metals or thermoset polymers like phenolic or reinforced reaction injection molded (RIM) urethane. The reasons for market penetration by PP replacement vary widely with an assortment of material design options chemical resistance, heat resistance, recycleability, processability, economics, and aesthetics. 

The polymer principally used in reaction injection molding is thermoset (cross-linked) polyurethane. Nylon (thermoplastic) and polyesters and epoxies (both thermosets) are also processed in this manner. 

The void content of pultruded composite rods have been studied using NMRI [IS]. Glass fiber-reinforced nylon rods with fiber contents of 51% by volume were first mixed with different catalyst contents following the reaction injection molding (RIM) process, and then pultruded with a pulling speed 18 inches... 

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