Manganese initiated graft pymerization of vinyl monomers onto collagen

Abstract

Graft copolymerisation of vinyl monomers such as methyl methacrylate (MMA). mcthyl acrylate (MAl and acrylonitrile onto collagen has been carried out using manganic ion as initiator. Collagen vinyl graft copolymers were characterised arter acid hydrolysis of the collagen back bone with 6N HCI. The molecular weights of the grafted vinyl polymeric chains were in the range of 2.89 to 18.32×10⁸.These values are in agreement with those obtained using Ce⁴⁺ initiation technique. The rate of grafting was in the order MMA>MA>AN. The number of grafting sites obtained from the molecular weight data indicated that the molecular weights of the isolated grafts are many times larger than the molecular weights of the tropocollagen molecules and the grafting sites are very few. These results are in agreement with those obtained by Ce⁴⁺ system. Proof of grafting has been provided by the I.R. spectra of the isolated grafted chains which showed characteristic amide absorption bands of the amino acids. Electron microscopy of the graft copolymers indicated the absence of cross-striations. A mechanism for the initiation coploymerisation using Mn³⁺ ion has been suggested.