Accession Number:

AD0712148

Title:

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

Descriptive Note:

Corporate Author:

SVENSKA TRAFORSKNINGSINSTITUTET STOCKHOLM

Report Date:

1969-05-14

Pagination or Media Count:

11.0

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

Subject Categories:

  • Physical Chemistry
  • Wood, Paper and Related Forestry Products

Distribution Statement:

APPROVED FOR PUBLIC RELEASE