INVESTIGATIONS OF THE PHYSICOCHEMICAL CHA RACTERISTICS OF FLAX BAST BY THE IR-ATR SPECTROSCOPIC METHOD

The method of IR-ATR spectroscopy has been used to analyze the physico -chemical characteristics of thin (0.2-0.4 mum) surface layers of flax bast on its external (bordering on the air) and internal (bordering o n cambium) surfaces. It has been found that, as bast ripens in the ext ernal side of its fibers, the degree of structural ordering of cellulo se macromolecules increases and, at the same time, it is maximum near the roots of the stalk and decreases as the top is approached. Besides , the concentration of adipose matter on the external side of bast mon otonically decreases while the concentration of pectines increases as one moves along the stalk from the button upwards. Also, the content o f adipose matter (for the lower and middle portion of the stalk) and p ectines (along the whole length of the stalk) is much higher at a late stage of ripening than at an early stage. The physico-chemical charac teristics of bast as to its internal surface differ sharply from those on the external surface and, at the same time, they are practically i ndependent on the degree of ripening of flax. It has been concluded th at IR-ATR spectroscopy ot the external surface of flax bast can be an effective method for analyzing and checking the physico-chemical chara cteristics and, consequently, the quality of flax raw material.