Abstract: The invention relates to crystalline polyethylene pieces having optimum crosslinking for use in storage and recovery of heat, and it further relates to methods for storage and recovery of heat using crystalline polymer pieces having optimum crosslinking for these uses. Crystalline polymer pieces are described which retain at least 70% of the heat of fusion of the uncrosslinked crystalline polymer and yet are sufficiently crosslinked for the pieces not to stick together upon being cycled above and below the melting point of said polymer, preferably at least 80% of the heat of fusion with no substantial sticking together.

Abstract: The invention relates to transparent or optically clear laminates and adhesive films used to make these laminates having a temperature utility range far greater than those previously developed and which are especially useful for windshields of high speed aircraft which need such a broad temperature range. These transparent adhesive films have a temperature utility in the range of -65.degree. F to at least 350.degree. F in laminates and comprise an ethylene/vinyl acetate copolymer having a vinyl acetate content in the range of 40% to 60%, the copolymer being partially hydrolyzed to form a terpolymer having a hydroxyl content in the range of 1% to 6%, the terpolymer in film form and/or laminate being heat treated and cross-linked to give the adhesive film. The laminates are made from transparent layers of glass and/or plastic bound together with the transparent adhesive film.

Abstract: By mixing one part of a prepolymer containing a polyamine partially polymerized with an organic epoxide and subsequently reacted with a fatty acid containing from 8 to 32 carbon atoms, and then reacting this prepolymer mixture with 3 parts of an organic epoxide, a composition was obtained which made a gas frothable, shear-stable, room temperature curing, low density foam. A particularly advantageous prepolymer was prepared using a polyamine selected from the group consisting of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine, partially polymerized with an organic epoxide having an average molecular weight of about 350 and having an epoxide equivalent of 185 to 192, and reacted with 2-10 weight percent linoleic acid.