styrene nanocomposites were synthesized by in-situ atom transfer radical polymerization at 110oc. the variations of monomer conversion and the linearity of semilogarithmic kinetic plot, some signs of living polymerizationand constant radical concentration in the reaction medium, were revealed by gas chromatography technique (gc). according to the gel permeation chromatography (gpc) results, the...

Mechanical testing of an advanced thermoplastic polyimide (LaRC-SI) with known variations in molecular weight was performed over a range of temperatures below the glass transition temperature. The physical characterization, elastic properties and notched tensile strength were all determined as a function of molecular weight and test temperature. It was shown that notched tensile strength is a ...

Pneumococcus DNA, of weight-average molecular weight 1.6 million by light scattering, had a weight-average length of 4300 A by electron microscopy. Thus, the average mass per unit length was 370 molecular-weight units per A, or approximately two times that expected (208) for a Watson-Crick double helix. This corresponds to an average of 3.6 strands per molecule, which is close to that obtained ...

In this study, pedigree data of 7170 lambs produced from 177 rams and 2182 ewes collected during 1989 to 2009 in the Shirvan Kordi sheep breeding station, were used for calculating inbreeding coefficients. The impact of inbreeding on the studied traits was investigated by including inbreeding coefficients for each animal as a covariate in the animal model. Average inbreeding coefficient of the ...

We develop new criteria that describe the minimum concentration limits controlling the spinnability of dilute and semi-dilute flexible polymer solutions with high molecular weight and varying polydispersity. By asserting that the finite and bounded extensional viscosity of the solution is the key material property determining the stability of a filament during spinning, we propose a new scaling...

in atom transfer radical polymerization (atrp) of methyl acrylate (ma) with polyvinyl acetate macroinitiator in bulk at 90°c the plots of ln [m]0/[m] increased linearly with reaction time. the apparent propagation rate constant (kp app) of the reaction was obtained from the linear curve and used to calculate the free macroradical concentration ([r°]) in polymerization medium. the [r°] and also ...

radiation degradation of chitosan is one of the most important methods to prepare antibacterial oligochitosans. in this study, the effect of solvent on the reduction of degradation dose and enhancement of the antibacterialactivity of chitosan against pectobacterium carotovorum (pc) has been considered.gamma radiation degradation was applied to chitosan as solid and aqueous solution at dose rang...