1949/04/01 by P. H. Hermans, A. Weidinger · 3 citations
Materials Science · #Advanced Cellulose Research Studies
paper · doi:10.1002/pol.1949.120040203
crossref issued 1949/04/01 · crossref published 1949/04/01 · crossref published-print 1949/04/01 · openalex publication_date 1949/04/01 · crossref published-online 2003/03/10 · crossref created 2003/04/16 · crossref deposited 2023/10/19 · openalex created_date 2025/10/10 · crossref indexed 2026/07/28 · openalex updated_date 2026/07/29
Abstract The method for the evaluation of the percentage crystallinity in cellulose preparations from x‐ray intensity measurements, previously described in detail (J. Appl. Phys., in press) is reviewed briefly and new material presented consisting of crystallinity percentages between 8% and 70%. Cotton, flax, and ramie possess equal crystallinity (70%) and so do the majority of rayons, independent of their degree of orientation and including cuprammonium and Lilienfeld rayons. Cellulose acetates saponified under varying conditions also yield almost the same value as rayon (40%). The New product Fiber G (du Pont) holds an exceptional position with 53% crystalline substance. In the series of native celluloses, wood pulp has about 65%, Valonia 65–70%, and bacterial cellulose about 40%. By dry grinding of rayon, a powder was obtained containing only slightly less than 10% crystalline substance, which on recrystallization in water, yields 2 product having the same crystallinity as rayon. The difference between the heats of wetting of the criginal and the recrystallized powder affords additional support of the results obtained.