Abstract: Vinyl ester resins of the type already having reactive liquid polymers reacted into the backbone of the resins, are cured in the presence of a reactive liquid polymer additive admixed with the prereacted vinyl ester resin. Heating of the system during cure causes the reactive liquid polymer additive to miscibilize with the vinyl ester base resin. The vinyl ester resin modified in the manner described above shows a significant enhancement in toughness as measured by fracture energy over unmodified counterparts or counterparts modified by known methods of adduction or admixing alone.

Abstract: Curable epoxy resins are toughened with statistical monofunctional carboxyl, amine or epoxy terminated reactive polymers and have low viscosities before cure thereby making them useful in a wide range of applications. The cured epoxy resin systems which are modified by the statistical monofunctional reactive polymers have physical properties, such as adhesion and elongation, generally equal to or better than those of cured epoxy resin systems modified with statistical difunctional reactive polymers. A process of preparation for the modified epoxy resin systems of the present invention includes admixing an epoxy resin with a statistical monofunctional carboxyl, amine, or epoxy-terminated reactive polymer in the presence of a curing agent and reaction therewith to form the toughened, cured epoxy resin system.

Abstract: Unsaturated polyester resins of the type already having reactive liquid polymers reacted into the backbone of the resins, are cured in the presence of a reactive liquid polymer additive admixed with the prereacted unsaturated polyester resin. Heating of this system during cure causes the reactive liquid polymer additive to miscibilize with the unsaturated polyester resin. The unsaturated polyester resin modified in the manner described above shows a significant enhancement in toughness as measured by fracture energy over unmodified counterparts or counterparts modified by known methods of adduction or admixing alone.

Abstract: Vinyl ester resins of the type already having reactive liquid polymers reacted into the backbone of the resins, are cured in the presence of a reactive liquid polymer additive admixed with the prereacted vinyl ester resin. Heating of the system during cure causes the reactive liquid polymer additive to miscibilize with the vinyl ester base resin. The vinyl ester resin modified in the manner described above shows a significant enhancement in toughness as measured by fracture energy over unmodified counterparts or counterparts modified by known methods of adduction or admixing alone.

Abstract: Curable epoxy resins are toughened with statistical monofunctional carboxyl, amine or epoxy-terminated reactive polymers and have low viscosities before cure thereby making them useful in a wide range of applications. The cured epoxy resin systems which are modified by the statistical monofunctional reactive polymers have physical properties, such as adhesion and elongation, generally equal to or better than those of cured epoxy resin systems modified with statistical difunctional reactive polymers. A process of preparation of the modified epoxy resin systems of the present invention includes admixing an epoxy resin with a statistical monofunctional carboxyl, amine, or epoxy-terminated reactive polymer in the presence of a curing agent and reaction therewith to form the toughened, cured epoxy resin system.

Abstract: Curable epoxy resins are toughened with statistical monofunctional carboxyl, amine or epoxy terminated reactive polymers and have low viscosities before cure thereby making them useful in a wide range of applications. The cured epoxy resin systems which are modified by the statistical monofunctional reactive polymers have physical properties, such as adhesion and elongation, generally equal to or better than those of cured epoxy resin systems modified with statistical difunctional reactive polymers. A process of preparation for the modified epoxy resin systems of the present invention includes admixing an epoxy resin with a statistical monofunctional carboxyl, amine, or epoxy-terminated reactive polymer in the presence of a curing agent and reaction therewith to form the toughened, cured epoxy resin system.

Abstract: Fiber reinforced composites are comprised of a vinyl resin composition and fibrous reinforcement material which is coated with a uniformly thin and continuous elastomeric coating. The coating is prepared from an aqueous dispersion containing a reactive liquid polymer composition, an epoxy resin and a curing agent.

Abstract: The present invention generally relates to statistical monofunctional terminated reactive liquid rubbers including a statistical monofunctional carboxylic-terminated reactive liquid rubber, a statistical monofunctional amine-terminated reactive liquid rubber, and a statistical monofunctional epoxy-terminated reactive liquid rubber. These polymers are pourable, making them useful in a variety of applications particularly as toughening agents for epoxy resins to which they impart good physical properties.

Abstract: Fibers are conveniently coated with a uniformly thin and continuous elastomeric coating by contacting the fibers with a (1) a water-dispersed reactive polymer, (2) epoxy resin, and (3) curing agent; and wherein said water-dispersed reactive polymer is a composition comprising. (a) a lower molecular weight reactive polymer, (b) a select solvent, (c) a dispersing agent, and (d) water. The elastomeric films have a Tg value of about 0.degree. C. or below. The elastomer coated fibers are useful as strengtheners and impact modifiers for brittle materials such as epoxy resins.

Abstract: Hard and strong epoxy resin products of high impact resistance are made from a di-epoxy compound, a smaller than equivalent proportion of a dicarboxylic acid which functions as a chain extender, and a bifunctional liquid elastomer, together with a curing agent active at elevated temperatures. Preferably the quantity of bifunctional liquid elastomer is about 5 to 10% of the amount of the di-epoxy compound.

Abstract: An elastomeric liquid polymer vulcanizate is prepared by admixing a major amount of a liquid carboxyl-terminated polymer, a minor amount of a dihydric compound, and a small amount of an amine having selectivity for a carboxyl-epoxide reaction with an epoxy resin having about two epoxide ##STR1## groups per molecule, casting the mixture in a mold, and heating it at from about 110.degree. C. to about 180.degree. C. until the composition cures. The vulcanizate has elastomeric properties, and is characterized by having two distinct polymer phases and having an ultimate tensile strength of over 1000 pounds per square inch and an elongation of over about 140 percent.

Abstract: Hard and strong epoxy resin products of high impact resistance are made from a di-epoxy compound, a smaller than equivalent proportion of chain extender which is preferably a bis-phenol, and about 5% (based on the amount of the di-epoxy compound) of a functionally terminated elastomer which is preferably a phenol terminated liquid copolymer of butadiene and acrylonitrile, together with a curing agent active at elevated temperatures.