Dipole moments of poly(trimethylene oxide) chains [CH2-CH2-CH2-0-]x were determined as a function of degree of polymerization and temperature by means of dielectric constant measurements in the thermodynamically good solvent carbon tetrachloride. The mean-square dipole moment was found to be directly proportional to the degree of polymerization x, or the number of skeletal bonds, thus demonstra...

The polymerization shrinkage of composite resins may affect negatively the clinical outcome of the restoration. Extensive research has been carried out to develop new formulations of composite resins in order to provide good handling characteristics and some dimensional stability during polymerization. The purpose of this study was to analyze, in vitro, the magnitude of the volumetric polymeriz...

Fabrication of poly(p-oxybenzoyl) (POB) nanowhiskers was examined by using reaction-induced crystallization of oligomers during the polymerization of p-acetoxybenzoic acid in liquid paraffin. Width of the POB whiskers was susceptible to polymerization temperature and it was efficiently controlled by a change in temperature during the polymerization. Increase in polymerization temperature just a...

The optimal control policies for a polymerization process, particularly for the batch free radical polymerization of methyl methacrylate, have been determined using a multiobjective optimization technique. The process objectives considered in the optimization include monomer conversion, polydispersity index, polymerization degree and total reaction time, weighted combined in a scalar objective ...

The coordination polymerization of ethylene in water as a reaction medium was studied. Rubbery amorphous branched polyethylene was obtained when a known cationic diimine-substituted methyl complex was employed as a catalyst precursor. High rates of up to 900 TOh(-1) (turnover frequency) were observed. In contrast to solution polymerization in an organic solvent, the rate of suspension polymeriz...

Various concentrations of actin (0.3 or 1 mM MgCl2, 1 mM ATP, 1 mM EGTA) reached their final degree of polymerization (measured by a pyrene dye attached to actin) earlier in the presence of cytochalasin B than in its absence. The curves relating concentrations of polymeric F-actin to total actin concentration were under these conditions highly nonlinear making an unambiguous extrapolation to ze...