Mercerization of cellulose: 1. Determination of the structure of Mercerized cotton

Abstract

The structure of Mercerized cellulose II has been determined using the intensity data from Mercerized cotton fibres and rigid body least squares refinement techniques. The crystal structure consists of an array of antiparallel chain molecules essentially identical to that found for regenerated cellulose II. The unit cell is monoclinic with dimensions a = 8.02 A ̊ , b = 8.99 A ̊ , c = 10.36 A ̊ (fibre axis), and γ = 116.6°; the space group is P2 1 and the cell contains sections of two cellulose chains which pass through the centre and corner of the ab projection. The final crystallographic R value was 0.263, based on intensity data for 30 observed and 11 unobserved non-meridional reflections. The CH 2OH groups of the corner chains are oriented near to the gt position while those of the centre chain are near to the tg position. The possibility of alternative side group orientations, most likely on the exterior of the cellulose II crystallites, has been demonstrated for both the Mercerized and regenerated structures. The percentage of these other orientations is small in the case of Fortisan (rayon) but substantial in the case of Mercerized cotton.