Reactive acrylic liquid polymers

New Energy Saving Reactive Acrylic Liquid Polymers for the Pressure Sensitive Adhesives Industry... 

Recently, hot melt PSA systems have been introduced and radiation curable PSA systems are at the commercial development stage. High solids (50%-70% by wt.) nonaqueous dispersion acrylic PSA systems have also been reported(1). Unlike the hot melt and radiation cured systems which require new capital outlay in coating head and/or curing (drying) equipment, BFG has developed PSA systems, based on Hycar 2100R reactive acrylic liquid polymers and isocyanate terminated prepolymer, which can be processed at 80% solids (by wt.) with equipment presently used in the PSA industry, namely, the reverse roll and knife-over-roll coater. 

This review introduces the method of active ester mtheris, and discusses its application to the preparation of a variety erf specialty polymers, including amphiphilic gels, graft copolymers, and side chain reactive and liquid crystalline polymers. The polymerization and copolymerization of activated acrylates by solution and suspension techniques are discussed, and polymer properties such as comonomer distribution, molecular weights, C-NMR spectra and gel morphology are reviewed. Potential applications of these polymers are also highlighted, and the versatility of active ester synthesis as a new dimension of creativity in macromolecular chemistry is emphasized. 

Acrylic adhesives are applied to the substrates to be bonded as a liquid mixture of unreacted methacrylate (or acrylate) monomers, polymers to thicken or toughen, reactive resins for strength, adhesion promoters and polymerization agents. Polymerization or curing is... 

A wide range of liquid polymers are crosslinked with reactive peroxides, such as benzoyl peroxide, diacyl peroxide, and various peroxyesters and peroxyketals. These are used to crosslink acrylic resins for a wide range of applications. Since these peroxides are inherently unstable, they are reduced in concentration for safe storage and use by dilution with cyclohexane, diallyl phthalate, or dimethyl phthalate. These diluents must be understood from an analytical perspective for proper role and source identification. 

HP Multipolymer Acrylic-based multipolymer sheet, Cyro HT-1 Polyimide, DuPont Hyccr Reactive liquid polymers, BFGoodrich... 

Hycar reactive liquid polymers produced by Goodrich Company are homopolymers of butadiene or copolymers of butadiene and acrylonitrile. The isomer content is largely cis/trans with vinyl (1,2-addition of butadiene) being 25% percent or less. They have reactive groups in both terminal positions of the polymer chain end and, optionally, may have additional reactive groups pendant on the chain. Hycar contains no solvent or other unreactive components. There are three types of reactive functional groups commercially available. They are carhoxyl, acrylate, vinyl, and secondary amine. 

Hycar vinyl-terminated liquid polymers (Hycar VTBN) have reactive acrylate or vinyl groups and can be reacted into systems involving curing by free radical mechanisms. The reactive vinyl groups are separate from the cis/trans vinyl unsaturation contributed by the polymerized butadiene of the polymer backbone. 

Two of the main considerations in the development of totally reactive liquid photopolymer systems are the resin(s) and the reactive diluents (monomers). The resins play a major role in determining the end properties and therefore the applications of the cured polymer. The reactive diluents are used to provide a fully reactive system with the appropriate reactivity, viscosity, coatability before cure and the desired crosslink density, chemical resistance and dielectric character once it is cured. The pho-toreactive monomers most commonly used are acrylate based derivatives because of the properties they impart, and their high reactivity and wide solubility range. 

The co-monomers such as vinyl acetate, acrylate esters, or carbon monoxide are fed together with ethylene, or introduced by liquid pumps, into the suction of the secondary compressor. The concentration in the feed of the co-monomer which is required to achieve a certain level of the co-monomer in the resulting polymer depends on the reactivity ratios, ri and r2, which are the ratios of rate constants of chain-propagation reactions [5]. The values for the co-monomers used in the high-pressure process are presented in Table 5.1-3. In the case of vinyl acetate, both reactivity ratios are identical and therefore the composition of the copolymer is the same as that of the feed. The concentration of vinyl acetate, for example, in... 

The acrylic core-shell polymers are considered to offer superior ultraviolet-light and thermal-oxidative aging properties than does the more conventional reactive liquid polymeric toughener, CTBN. Hence, there is current interest in the use of acrylic core-shell polymers as tougheners for adhesives and composite matrices that possess a relatively high glass-transition temperature. 

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