Accession Number : AD0712148

Title :   FOUR SECONDARY AND THE GLASS TRANSITION TEMPERATURES OF CELLULOSE, EVALUATED BY SONIC PULSE TECHNIQUE,

Corporate Author : SVENSKA TRAFORSKNINGSINSTITUTET STOCKHOLM

Personal Author(s) : Back,Ernst L. ; Didriksson,E. Inger E.

Report Date : 14 MAY 1969

Pagination or Media Count : 11

Abstract : The change in modulus of elasticity with temperature has been examined between -70 and +375C in the dry state for one paper of cotton linters and two bleached pine kraft papers. The modulus of elasticity was evaluated for the machine and cross directions by a sonic pulse technique, subsequent to 4 seconds of thermostating in a plane press nip. Four temperature ranges with a rapid change in modulus of elasticity appear indicating secondary transitions, before a considerable final fall of the modulus. A previous heat treatment of the papers at 190C, i.e. a thermal autocrosslinking of cellulose chains, appeared to move transition II upwards and the other three transitions slightly downwards. From a comparison of untreated and heat-treated papers, the glass transition temperature of dry cellulose was estimated to 230C. (Author)

Descriptors :   (*CELLULOSE, TRANSITION TEMPERATURE), (*PAPER, TRANSITION TEMPERATURE), MODULUS OF ELASTICITY, COTTON, CROSSLINKING(CHEMISTRY), ACOUSTIC PROPERTIES, SWEDEN

Subject Categories : Physical Chemistry
      Wood, Paper and Related Forestry Products

Distribution Statement : APPROVED FOR PUBLIC RELEASE