ANALYSIS OF LIGNIN BY PYROLYSIS GAS-CHROMATOGRAPHY .2. EFFECT OF BOROSILICATE GLASS-FIBERS ON PYROLYSIS PRODUCT COMPOSITION

Curie-point copyrolysis of akamatsu (Pinus densiflora Sieb. et Zucc.) wood with several inorganic substances was performed for obtaining lar ge yields of lignin-derived guaiacol derivatives. Of the chemicals scr eened, borosilicate glass fibers best helped in increasing the total y ield of guaiacol derivatives. In particular, pyrolysis of the sample s andwiched between two sheets of heat-resistant paper made of borosilic ate glass fibers (the sandwich-2 method) was effective. At an optimum temperature of 500-degrees-C, the sandwich-2 method increased the yiel ds of guaiacol 2.1 times, 4-vinylguaiacol 2.0 times, and eugenols (eug enol, cis- and trans-isoeugenols) 1.7 times the yields from the standa rd method which did not use the fibers. Consequently, 1.6 times more g uaiacol derivatives were produced by the sandwich-2 method than by the standard method. From these results, several advantages of the sandwi ch-2 method for analytical pyrolysis of lignocellulosic materials were proposed as follows: (1) reduction of excess pyrolytic degradations o r suppression of secondary pyrolysis reactions, (2) promotion of cleav age of the beta-aryl ether linkage, and (3) promotion of cleavage of t he bond between the C(alpha) atom and the aromatic ring. These advanta ges of the sandwich-2 method made the total yields of guaiacol derivat ives larger than those from other pyrolysis methods: namely, the stand ard and mixing methods.