Abstract: A two-step process for making reactive unsaturated polyester resins is disclosed. First, an aromatic dicarboxylic acid derivative reacts with 2-methyl-1,3-propanediol (MPD) to produce an ester diol intermediate. The intermediate reacts with maleic anhydride and from about 15 to about 40 mole percent, based on the total glycol requirement, of propylene glycol. By shifting some glycol to the second step, and by using propylene glycol there, resin producers can easily make MPD-based UPR having a fumarate content greater than 85%. The resins give thermosets with improved physical properties, including excellent water resistance.

Abstract: Polyol compositions suitable for use in the production of fibre-reinforced rigid polyurethane foam comprises (a) at least one amino polyol obtainable by reacting an alkylene oxide with an initiator which has a functionality greater than 2, at least one aromatic ring and at least one amino nitrogen atom and (b) at least 3% by weight, based on the total weight of (a) plus (b), of an adduct of a tertiary amine and an alkylene carbonate. These novel polyol compositions provide foam-forming formulations of suitable viscosity without the need to use a CFC blowing agent and also combine high reactivity with a broad reactivity profile.