POLYESTERAMIDES FROM LINSEED AND SOYBEAN OILS FOR PROTECTIVE COATINGS - DIISOCYANATE-MODIFIED POLYMERS

New polymeric coating materials have been prepared by a triethylenediamine-catalyzed reaction of hydroxyl-terminated polyesteramides (HTPA) from soybean or linseed oils with diisocyanates. Eight dibasic acids or anhydrides were reacted with excess N,N-bis(2-hydroxyethyl) fatty amide to yield HTPA; those containing 10 mole per cent excess gave isocyanate-modified polymers with best overall film properties. Reactivity of four diisocyanates with a linseed-HTPA was measured by disappearance of the isocyanate band in the infrared. Depending on chemical composition, structure and curing conditions, films prepared from these polymers have a wide range of drying characteristics, hardness and chemical resistance. Drying times of linseed HTPA-urethane polymer films varied from 0.3 to 48 hr, hardness values (Sward) were from 4 to 70, alkali resistance ranged from 2 to 126 min and the hydrochloric acid and xylene resistances were good to excellent. Impact resistance exceeded 160 in.-lb for all films except two. The soybean-derived polymer films likewise exhibited a wide range of properties; they chiefly differed from linseed-derived films in having greater flexibility and improved alkali resistance. © 1969, American Oil Chemists’ Society. All rights reserved.