STUDY OF THE SUPRAMOLECULAR STRUCTURE OF CELLULOSE BY THE RESPONSE TO THE IMPACT OF INHOMOGENEOUS TEMPERATURE FIELD
Mechanical characteristics of wood materials are largely determined by the supramolecular structure of fiber-forming components of wood - cellulose. Investigation of the microstructure of wood is associated with a number of difficulties due to the fact that the timber - a complex porous composite with interdependent on each other components which makes supramolecular structure of this material quite sensitive to changes in the environment. Therefore, the actual problem is the development of methods of nondestructive testing of changes of the supramolecular structure of cellulose directly into the samples of timber. To this end, the response of wood on the impact of an inhomogeneous temperature field is considered. It is shown that the cellulose crystallites are centers of polarization in the fiber-forming part of biocomposite - wood, placed in the non-uniform temperature field. An expression describing the dependence of the logarithm of polarization probability of cellulose on the degree of its crystallinity for various ratios of crystalline and amorphous parts of the cellulose is got. As a result of analysis based on the constructed expression of plots it was revealed that the break point of evaluation curves practically coincides with the known average crystallinity of woodpulp. This suggests that if the degree of crystallinity of the cellulose in wood exceeds this barrier value, the probability of polarization of side groups of the macromolecules begins to increase sharply with increasing temperature relative inhomogeneity. The experiment confirms that non-uniform temperature field leads to appearance of electric field in the sample timber, the nature of which is the thermal polarization phenomena in cellulose crystallites. Therefore, measuring the potential difference of occurring field, you can explore the features of the supramolecular structure of cellulose. There is an opportunity to develop electrical and measuring ways to control changes of the supramolecular structure of cellulose.