Molecular Weight Distribution of Elastomers

Rheological Method for Determining Molecular Weight and Molecular Weight Distribution

The molecular-weight distribution of glycosaminoglycans.

1. A rapid and sensitive method for the accurate estimation of the molecular-weight distribution of keratan sulphate and chondroitin sulphate isolated from adult bovine nasal septum and intervertebral disc is described. The method utilizes gel chromatography of reductively labelled glycosaminoglycan and end-group estimation of number-average molecular weight for each fraction across the peak of...

Swelling dynamics of liquid crystal elastomers swollen with low molecular weight liquid crystals.

We experimentally investigated the swelling behavior of thin films (approximately 150 microm) of liquid crystalline elastomers (LCEs) by low molecular weight liquid crystals (LMWLCs). The two LMWLCs used are the well-known nematic liquid crystals, 4-n-pentyl-4-cyanobiphenyl, and 4-methoxy-benzilidene-4-butyl-aniline. Both polydomain (POLY) and monodomain (MONO) LCE swelling are studied. In MONO...

Calculation of Molecular Weight Distribution from Molecular Weight Moments in Free Radical Polymerization

A novel method is presented for the calculation of weight chain length distribution in free radical polymerization of vinyl monomers. In the proposed method, polymerization kinetic equations and molecular weight moment equations are used in conjunction with a function that defines the weight fraction of polymer in a finite chain length interval. The entire range of molecular weight is divided i...

Intracellular Distribution of Low Molecular Weight Rna in Chironomus Tentans

Low molecular weight RNA species are described in isolated nuclear components and cytoplasm of salivary gland cells of Chironomus tentans. In addition to 4S and 5S RNA and RNA in the 4-5S range previously described, at least three other components in the range below 16S are present. RNA, the molecular weight of which was estimated to 2.3 x 10(5) and designed 10S RNA, can be observed only in nuc...