11979synthetic organic polymersPT0000-00-00 00:00:00BT11969synthetic polymersPTNT11984acrylic polymersPTNT11985polyacetalesPTNT11988polyamidsPTNT11987polyestersPTNT11986polyethersPTNT11982polyhydrocarbonsPTNT11989polyurethanesPTNT11983vinylic polymersPT