Thermal behavior of some homogeneously polymethyl methacrylate (PMMA)‐grafted high α‐cellulose products

Abstract

ABSTRACT:The graft copolymerization of methyl methacrylate (MMA) onto high ␣-cellulose was carried out homogeneously in an N,N-dimethyl acetamide/lithium chloride solvent system by using benzoyl peroxide as radical initiator. The rate of grafting was evaluated as a function of concentrations of initiator and monomer, reaction time, and temperature. The grafted products were characterized with the help of infrared spectroscopy, whereas the thermal decomposition of optimum PMMA-grafted high ␣-cellulose was studied using TGA, DTG, and DTA techniques at two heating rates, 10 and 20°C/min, in nitrogen atmosphere in the range of room temperature to 650°C. Three major decomposition steps were identified and the relative thermal stabilities of the PMMA-grafted high ␣-cellulose products were assessed. The kinetic parameters for the three decomposition steps were estimated with the help of two wellknown methods. The thermal stability of the grafted products decreased with the increase of graft yield (GY). Crystallinity or peak intensity of wide-angle X-ray diffraction patterns decreased with the increase of GY.

Semi-Natural Superabsorbents Based on Starch-g-poly(acrylic acid): Modification, Synthesis and Application

“…Afterwards, the starch solution was cooled down to room temperature. Then, 2 mL of CAN solution (0.005 mol/dm 3 ) was poured into the solution in order to activate reactive sites in the starch backbone and initiate free radical polymerization of acrylic monomers [ 30 , 31 ]. AA (5.998 g) monomer neutralized beforehand with NaOH was added as grafting monomer and after that 0.05% (relative to monomer) of MBA was added as crosslink agent.…”

Synthesis and characterization of carboxymethylcellulose and methyl methacrylate graft copolymers

“…The initial decomposition temperature (IDT) was calculated from the end of the initial straight‐line portion of the curve, where the actual decomposition was believed to have occurred (Das et al , 2004; Abdel Razik, 1996; Khan, 2005).…”

Alpha cellulose from industrial and agricultural renewable sources like short flax fibres, ears of corn and wheat-straw and its transformation into cellulose acetates

“…Alpha cellulose means very pure cellulose. 11 Alpha cellulose has been extensively used, for example for the preparation of polymethyl methacrylate-grafted high alpha cellulose products, 12 and for the preparation of paper from olive tree residues. 13 Alpha cellulose has been extracted from sugarcane bagasse waste, too, indicating the importance of an environmentally friendly chlorine-free approach.…”