THE WAY OF STEREOREGULARITY DETERMINATION OF POLYPROPYLENE

článek v časopise - ostatní, Jost

angličtina

The purpose of this contribution is to evaluate and compare isotactic index determination of polypropylene homopolymer by extraction and solubility methods. A series of nine PP powder samples possessing molecular weights in the range from 29 -103 to 154-03 g/mol was investigated. Both the methods afforded fractionation of polypropylene into two portions, the soluble fraction and the insoluble one. Extractions were carried out in a modified Kumagawa extractor. Solvent extracts were obtained from polypropylene powders using several organic solvents (n-pentane, n-hexane, n-heptane, and n-octane) at their boiling points. Soluble fractions were prepared by dissolving polypropylene powder in high boiling solvents (xylene, decahydronaphthalene, and 1,2,3,4-tetrahydronaphthalene) and cooling polymer solutions to 23 degree C. All the fractions were characterized using 13C-NMR, DSC, and SEC methods. Comparison of extraction and solubility methods showed a significant differences in the amount, structure, molecular weight, and crystalinity of soluble and insoluble fractions

Isotactic index, polypropylene, extraction

HOZA, A.; KRATOCHVÍLA, J.; HERMANOVÁ, S.

2008

9. 9. 2008

1213-7103

Chemické listy

102

15

Česká republika

s1202

s1206

5