Abstract
Cerium (Ⅳ) ion-initiated graft copolymerizations of acrylamide and of acrylonitirile to silk fibroins were investigated. When acrylamide was used, the change in ceric ammonium nitrate concentration exhibited a maximum in degree of grafting at 0.01 M. Also observed was that the change in acetic acid content in reaction media gave a maximum in degree of grafting at 7% acetic acid in water. Degree of grafting was increased generally with increase in acrylamide concentration reaction time and reaction temperature. When acrylonitrile monomer was used for grafting,different results were obtained. Addition of nitric acid was more effective in enhancing the degree of grafting than the addition of acetic acid.Generally the grafting of acrylonitrile to silk fibroins was less efficient than the grafting of acrylamide. The portion of grafted silk fibroins insoluble in Lowe's reagent exhibited the IR absorption bands characteristics to both vinyl polymers and silk fibroins, indicating the grafting of vinyl monomers to silk fibroins. To examine the molecular weight of graft vinyl polymer, a sample of grafted silk was hydrolyzed by 10% sodium hydroxide. Viscosity measurements indicated that the molecular weight of the graft polymer was in the range of 105.
단백질 섬유인 견섬유에 ceric ammonium nitrate를 촉매로 사용하여 acrylamide 또는 acrylonitrile을 그라프트공중합 하였다. 공중합의 표준반응조건은 세륨염 0.025 M, acryamide 0.5 M, 초산 25%, 온도 30$^{\circ}C$, 반응시간 3시간으로 하였으며 견섬유의 욕비(bath ratio)는 1:200으로 하였다. 이상의 반응조건에서 세륨염의 농도가 0.01 M 일 때와 7% 초산수용액일 때에 그라프트율이 최대로 되었다. Acrylonitrile을 단위체로 사용하면 질산용액에서의 그라프트율이 초산수용액에서 보다 높았지만, acrylamide 사용시와는 달리 그라프트율은 현저히 낮았다. 이밖에 그라프트된 견섬유의 Lowe시약(동-글리세린 수용액)에 대한 용해도, 적외선 분석 및 분자량을 조사하고 호모 중합체의 생성에 대하여 검토 하였다.