Glossary of terms used in the polyurethanes business

Courtesy of Smithers-Rapra & Cromar Solutions Ltd, UK

 

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

PET An abbreviation for poly(ethylene terephthalate).

PIR Polyisocyanurate, also referred to as PIR, belongs with PUR to the family of polyurethanes (abbreviation: PU). In PIR foams, the proportion of MDI is higher than for PUR and instead of a polyether polyol a polyester derived polyol is used in the reaction. Catalysts and additives used in PIR formulations also differ from those used in PUR formulations. PIR closed-cell foams are mostly used as rigid thermal insulation foam where superior thermal and fire resistance properties are requested. The typical thermal conductivity value of PIR is 0.023 W/mK.

Plastics Synthetic polymeric materials.

Polar A molecule having positive or negative electrical charges permanently separated.

Polyester A polymer containing ester linkages (-O-C-). The polyesters used in polyurethane technology contain reactive hydroxyl end groups.

Polyether A polymer containing ether linkages (-C-O-C-). The polyethers used in polyurethane technology contain reactive hydroxyl end groups.

Polyisocyanurate Polyisocyanurate, also referred to as PIR, belongs with PUR to the family of polyurethanes (abbreviation: PU). In PIR foams, the proportion of MDI is higher than for PUR and instead of a polyether polyol a polyester derived polyol is used in the reaction. Catalysts and additives used in PIR formulations also differ from those used in PUR formulations. PIR closed-cell foams are mostly used as rigid thermal insulation foam where superior thermal and fire resistance properties are requested. The typical thermal conductivity value of PIR is 0.023 W/mK.

Polymer (Copolymer) A high molecular weight substance, natural or synthetic, which can be represented as a repeated small unit (monomer). A copolymer contains more than one type of monomeric unit.

Polyol A substance containing several hydroxyl groups. A diol, triol, and tetrol contain 2, 3 and 4 hydroxyl groups respectively.

Polyurea Diisocyanates react with diamines to yield polyureas. The reaction is very fast and results in strong polymer, popular for structural foam and coating applications.

Polyurethane Polymeric substance containing many urethane linkages (-N-C-O-). Abbreviated as PU.

Pot-Life The total time that a urethane masterbatch / system is chemically stable (e.g. during coating applications before the product ‘cures’).

PPDI An abbreviation for p-phenylenediisocyanate and 1,4-diisocyanato-benzene.

Prepolymer A polyurethane reaction intermediate made by reacting isocyanate with a polyester or polyether, in which one component is in considerable excess of the other.

PUR An abbreviation for Polyurethane foam where a polyether polyol is used in the reaction. PUR foams, together with PIR (Polyisocyanurate)-foams, belong to the family of Polyurethanes (abbreviation: PU).