POLYMERIC MATERIALS
Copolymers, desirably having a molecular weight of from 500 to 20000, of aminoesters or aminoamides of (meth)acrylic acid and (meth)acrylamides at a molar ratio of from 10:1 to 60:1, particularly from 12:1 to 50:1 and especially about 20:1, can act as gas hydrate inhibitors in water containing hydrocarbon gas streams. Desirably the aminoesters or aminoamides are N-alkyl-amino(esters or amides) in particular of the formula (I): H<SUB>2</SUB>C=CR<SUP>1</SUP> C(O)XR<SUP>2</SUP>NR<SUP>3</SUP>R<SUP>4</SUP> (I) where R<SUP>1</SUP>, R<SUP>2</SUP>, R<SUP>3</SUP>, R<SUP>4</SUP> and X have defined meanings and the (meth)acrylamides are of the formula (II): H<SUB>2</SUB>C=CR<SUP>6</SUP>C(O)NR<SUP>7</SUP>R<SUP>8</SUP> (II) where R<SUP>6</SUP>, R<SUP>7 </SUP>and R<SUP>8</SUP> have defined meanings. Methods of treating gas water mixtures using the copolymers to inhibit gas hydrate formation are described.