New aspects in cationization of lignocellulose materials. IX. Flame retardancy effect of modification with nitrogen and sulfur containing groups

Abstract

SynopsisLignocellulose materials were modified with 3-chlor-2-hydroxypropyltrimethylammoniumchloride, 1,3-bis(3-chlor-2-hydroxypropyl)imidazoliumhydrogensulphate, and 2-chlorethyl-' sodiumsulphonate and the flame-retardant properties of materials obtained were studied. The flame-retardant effect was proved using the limited oxygen index (LOI) method and values up to 32.8 vol I of oxygen were determined. The LO1 values were higher when the modification was done without using NaOH for activation, but in that case the alkylating groups were not chemically bonded to the material. The NaOH activation was necessary to obtain material with flame-retardant properties stable against washing. No synergistic effects were observed when the material was modified with both nitrogen-and sulfur-containing groups.

Flame Retardancy Effect of Elemental Sulphur Caused by Covering the Lignocellulose Materials

“…When the beech boards were used instead of sawdust and the formic acid was replaced with phosphoric acid, the effect was even more dramatic.The LOI of unmodified board is 23.1 vol. % of oxygen (Simkovic et al 1987), while this value is increased to 26.2 when the boards were activated for one hour in phosphoric acid (Tab. l, exp.…”

“…The lignocellulose materials used were: (4-O-methyl-Dglucurono)-D-xylan in Na* form, beech sawdust (fraction greater than 1.4 and smaller than 2 mm) and homogeneous beech boards, sawed from one piece of wood with a density of 0.772 g/cm 3 , to dimensions of 80 x 10 x 4 mm äs characterized previously (Simkovic et aL 1987). The materials were activated from 5 min to l hour with the twenty-fold of water, inorganic or organic acids at room temperature.…”

Cationization of polysaccharides: A path to greener derivatives with many industrial applications

“…Complex agricultural products Many other materials have been cationized with CHP-TAC, among them, agricultural by-products that contain lignin together with polysaccharides, mainly cellulose and hemicelluloses. In 1980s, a series of ten articles with regard to the cationization of lignocellulosic materials such as beech sawdust, aspen wood and spruce wood meal were published [124, [170][171][172][173][174][175][176][177][178]. The reaction of corn cob meal, allowed the extraction of modified arabinoglucuronoxylans [179].…”