polyacrylontrile synthesis, via atom transfer radical polymerization, is studied in various initiator concentrations, transitional metal catalyst and different concentrations of cubr2. the variations of monomer conversion and the lin-earity of semi-logarithmic kinetic profile which is the evidence of living polymerization and constant radical concentration in the reaction medium, were revealed ...

Objectives: The aim of this study was to compare polymerization depth of two bulk-fill and one conventional composite cured for different times. Methods: This in vitro experimental study was conducted on 54 composite samples (2×4×10mm) fabricated of Tetric N-Ceram bulk-fill, x-tra fil bulk-fill, and Grandio conventional composite cured for 20, 30, and 40 seconds. The microhardnes...

this is a report on the study of high melt flow, highly isotactic polypropylene homopolymer synthesized in liquid monomer using a fifth generation ziegler-natta catalytic system. at highest catalyst productivity, the response of thecatalyst to hydrogen as chain transfer is studied. melt flow rate is controlled by hydrogen as chain transfer from 0.4 to 300 g/10min with changing the amount of hyd...

Investigations of polymerization rates in an acrylamide-based photopolymer are presented. The polymerization rate for acrylamide and methylenebisacrylamide was determined by monitoring the changes in the characteristic vibrational peaks at 1284 and 1607 cm(-1) corresponding to the bending mode of the CH bond and CC double bonds of acrylamide and in the characteristic peak at 1629 cm(-1) corresp...

The polymerization kinetics of rabbit skeletal muscle actin was studied by following the increase in fluorescence of tracer amounts of actin conjugated to N-pyrenyl iodoacetamide. The observed polymerization kinetics could be precisely fit by numerical integration of equations describing a nucleation-elongation process. Under all conditions tested, the rate of nucleation was proportional to the...

The kinetics of acrylic acid (AA) solution polymerization was investigated by polymerizing 30 wt % aqueous AA solutions at pH values ranging from 2.2 to 9.9. The polymerization rate was determined with differential photocalorimetry and was found to be a strong function of the solution pH and the ionic strength. Although the polymerization rate decreased with increasing pH below pH 6.5, an incre...