PROPERTIES OF BRANCHED AND NETWORK POLY(VINYL ALCOHOLS) PREPARED WITHPOLY(VINYL ALCOHOL) HAVING ALDEHYDE GROUPS AT THE CHAIN-ENDS

Branched and network poly(vinyl alcohols) (PVAs) were prepared with in ter-acetalization of the PVA with aldehyde groups at the chain ends wh ich was prepared by the cleavage of 1,2 glycol bonds in commercial PVA . The numbers of branches estimated from molecular weights were compar ed with those estimated by theory. Huggins' constant and crystallinity decreased with increasing branch number. Dissolution of branched PVAs into dimethylsulphoxide was not so easy compared with commercial PVA. The colour of branched PVA-iodine complex decreased rapidly with stan ding while that of commercial PVA decreased gradually. Network PVAs wi th Young's modulus of 1-8 MPa were prepared.