Abstract: A thermoplastic polyester urethane molding composition is disclosed having low compression set and high elastic modulus and which comprises the reaction product of a poly(epsilon-caprolactone) polymer, a hydroxy terminated polyol, an organic diisocyanate and a siloxane polymer. More specifically, by adding the siloxane polymer and maintaining a mole ratio of isocyanate to isocyanate-reactable hydroxy grouping in the range of from about 1.05 to about 1.3 or higher, it is possible to produce an improved molding composition having allophanate cross-links. The allophanate linkage breaks down at molding temperatures and reforms upon cooling thereby allowing an easily moldable thermoplastic urethane polyester which, after molding, will maintain its shape and have characteristics of a thermoset material. Additionally, the use of the siloxane polymer improves certain physical properties of the reaction product such as tensile and modulus of elasticity.

Abstract: A light-sensitive composition comprising novel arylglyoxyalkyl acrylates that exhibits useful light sensitivity. The basic structure of the new compositions, which may also themselves be polymerized are as follows: ##EQU1## wherein Ar represents an aromatic structure selected from the group consisting of benzene, naphthalene and substituted products of each, R.sub.1 represents an alkyl group having from one to ten carbon atoms, R.sub.2 represents a grouping selected from the group consisting of hydrogen, or a lower alkyl group having from one to five carbon atoms and R.sub.3 represents an alkenyl group having from one to 10 carbon atoms and singular unsaturation. The light-sensitive compositions may themselves be utilized in photochemistry as photopolymers, they may be combined with suitable solvents and additives or polymerized with suitable backbone polymers to provide substances which can be used as light-sensitive coatings.