Mc. Matias et al., Comparative spectroscopic study of the modification of cellulosic materials with different coupling agents, J APPL POLY, 75(2), 2000, pp. 256-266
The reactions of two cellulosic materials (an industrial cellulosic by-prod
uct from a Kraft. pulp mill facility and a reference material) with three c
oupling agents, used to improve compatibility between cellulosic reinforcem
ents and thermoplastic matrices, were studied by diffuse reflectance Fourie
r-transform infrared (DRIFT) spectroscopy and diffuse reflectance ultraviol
et-visible spectroscopy. A maleated polypropylene wax (Epolene E-43(TM)) an
d two silanes (N-2-aminoethyl-3-aminopropyltrimethoxysilane and methyltrime
thoxysilane) were used as coupling agents. The two cellulosic materials rea
cted in a similar way and the three coupling agents were covalently bonded
to the cellulose. For the aminosilane, a reaction with cellulase involving
a fraction of the amino groups was detected. A simple method, based on the
analysis of the oxidation kinetics of treated and untreated materials, was
developed to compare the degree of cellulose modification achieved by each
coupling agent. The analysis revealed that a reduced fraction of the cellul
ose reactive groups was converted by esterification with the maleated polyp
ropylene. However, when applied in the appropriate conditions, the two sila
nes converted most of such cellulose reactive groups. Finally, the reaction
of cellulose with mixtures of coupling agents was studied. The aminosilane
-treated cellulose reacted with the maleated polypropylene with formation o
f amide links. (C) 2000 John Wiley & Sons, Inc.