Characteristics of Poly (vinyl alcohol) grafted Cellulose Fiber

Abstract

Characteristics of poly (vinyl alcohol) (PVA) grafted pulps were studied in view of making use for paper making. The results are as follows:(1) Water retention value (WRY) by centrifugal method increased and moisture regain decreased with the increase of grafting per cent of the grafted pulp. The decrease in moisture regain could be explained by the fact that cellulose fiber was surrounded by PVA chain and the hydroxyl groups in cellulose chain and PVA chain interacted each other. The increase in WRV would be caused by the remarkable increase in free water in which change could be negligible in the normal WRV measurement. Because, the grafted per cent is higher, the grafted fiber is more elastic and trends to keep more free water.(2) From X-ray analysis, it was found that grafted PVA chain had very low crystalinity and the existence of the interaction between hydroxyl groups in the cellulose chain and PVA chain was assumed.(3) The strength properties of the web prepared from grafted pulps were affected by the grafting per cent and the changes were depended upon its pulp grade. Above all, the increase in tensile strength of PVA grafted SP web was remarkable. Such changes in tensile strength seemed to be related to specific volume of the web and might be interpreted by adhesive effect of PVA.(4) In the strength properties of the web prepared from the mixture of grafted and original pulp, any potential feature was not found except some limited case.