Abstract: A method for extending the gelation time of an oxidized polysaccharide to react with a water-dispersible, multi-arm amine to form a hydrogel is disclosed. The extension of the gelation time is accomplished by using a chemical additive. The method also extends the time for the hydrogel to become tack-free, and may also be used to decrease the degradation time of the hydrogel. The chemical additive reacts with the functional groups of the oxidized polysaccharide or the water-dispersible, multi-arm amine, thereby reducing the number of groups available for crosslinking. The use of the resulting hydrogel for medical and veterinary applications is described.

Abstract: A method is provided for evaluating relative wear life polymeric specimens intended for use at high temperature under high wear conditions.

Abstract: Polyimide resin compositions that contain an aromatic polyimide, graphite and a sepiolite filler, or a mixture of a sepiolite filler and a kaolin filler, are found to exhibit low wear and high thermal oxidative stability. Such compositions are especially useful in molded articles that are exposed to wear conditions at high temperatures such as aircraft engine parts.

Abstract: Temperature switchable pressure sensitive adhesives comprising an elastomer and a crystallizable abietic acid derivative as tackifier are described. These pressure sensitive adhesives exhibit a sharp reduction in peel strength when the temperature is raised above the switching temperature. The adhesive properties of these adhesives may be readily tuned by adjusting the ratio of the elastomer and the crystallizable tackifier, and by altering the crystallizabe group on the tackifier. The temperature switchable pressure sensitive adhesives have use in medical, consumer, and industrial applications.

Abstract: This invention concerns a process for polymerizing cyclic oligomers to homopolymers or copolymers, conducted in the presence of one or more linear polymers.

Abstract: This invention concerns a process for the addition of volatile materials to prepolymers prior to or during solid state polymerization processes and the subsequent conducting of said solid state polymerization process.

Abstract: A process which can be used in oligomerization, polymerization, or depolymerization such as, for example, the production of a polyester is provided. The process comprises contacting a carbonyl compound, in the presence of a composition, with an alcohol. The catalyst comprises a catalyst having the formula of M.sub.x Ti.sup.(III) Ti.sup.(IV).sub.y O.sub.(x+3+4y)/2 wherein M is an alkali metal, Ti.sup.(III) is titanium in the +3 oxidation state, Ti.sup.(IV) is titanium in the +4 oxidation state, x and y are numbers greater than or equal to zero wherein if x equals zero, y is a number less than 1/2.

Abstract: Poly(alkylene arylates) having excellent optical properties are disclosed and can be prepared using an organic titanate-ligand catalyst solution containing organic silicates and/or zirconates and, preferably, certain phosphorus compounds.