HIGH-STRENGTH POLY(METH)ACRYLAMIDE COPOLYMER HYDROGELS

The hydrogels described here are copolymers of acrylamide and methacry lamide highly cross-linked with piperazine diacrylamide or 4,7,10-trio xa-1,13-tridecanediamine diacrylamide by radical polymerisation in hig hly concentrated aqueous and aqueous gelatin solutions. The hydrogels were characterised by their compressive strength, refractive indices, densities, 'free' water contents and degree of swelling. The hydrogels cross-linked with piperazine diacrylamide gave strong glassy hydrogel s, which we have termed ''hydroglasses''. Cross-linking with 4,7,10-tr ioxa-1,13-tridecanediamine diacrylamide, which contains a long flexibl e spacer, did not result in a more elastic gel. Polymerisation in an a queous gelatin solution improved the mechanical properties of the gel enormously.