Synthesis and Characterization of Water Reducible MMA-MMA Copolymers
Author: Hua-Jung Hu
Publisher:
Published: 1995
Total Pages: 146
ISBN-13:
DOWNLOAD EBOOK"Water reducible copolymers based on methyl methacrylate (MMA) and methacrylic acid (MAA) with molecular weights of 25,000 to 35,000 were synthesized by free-radical polymerization. Optimization of the process to achieve high yield and desired molecular weight were studied. The results showed that polymers synthesized in THF were water reducible, whereas that synthesized in 1, 4-dioxane were not water reducible. The viscosity studies of the water reducible polymers showed a decrease in viscosity in the first stage of reduction followed by a maximum viscosity at further water reduction (about 25-28% ), and a steep viscosity drop at approximately 20% solid. Newtonian behavior was observed in the shear stress vs. shear rate curves for the polymers solution below 20% solid. The rate of water reduction over the range investigated, had no effect on the viscosity of the diluted polymer solutions. Transmission electron microscopy (TEM) studies were performed to visualize the polymer particles in the reduced polymer state. Both isolated and agglomerated polymer particles were observed. The isolated polymer particles were about 5nm in diameter. The diameter corresponds well with what would be predicted a spherical polymer particle formed from a single molecule"--Abstract, leaf iii.