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The effect of molecular weight on the cross section and properties of polyacrylonitrile precursor and resulting carbon fiber
Author(s) -
Tsai JinShy,
Lin ChungHua
Publication year - 1991
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1991.070421124
Subject(s) - polyacrylonitrile , materials science , fiber , exothermic reaction , polymer , composite material , polymer chemistry , carbon fibers , crystal (programming language) , atmospheric temperature range , chemical engineering , organic chemistry , chemistry , thermodynamics , composite number , physics , computer science , engineering , programming language
In this study, we investigated the effect of molecular weight in the range 1.65−4.29 × 10 5 ( M w ) on the cross section, surface, thermal, and mechanical properties of polyacrylonitrile (PAN) precursor and its resulting carbon fiber. From the results, it can be seen that the molecular weight, with the same solid content of polymer, changes from 1.65 × 10 5 to 4.29 × 10 5 and the cross section of PAN precursor changes from a circular shape with no notable grooves surface to a been shape with a surface containing deep and straight grooves. PAN precursor with higher molecular weight has a higher onset of exothermic temperature and a higher peak temperature, but has a higher aromatization index (AI value) due to its thin and flat cross section, which causes rapid cyclization during oxidation. An increase in molecular weight results in an increase in crystal size and preferred orientation and a decrease in average pore diameter. This decrease can improve the mechanical properties of PAN precursor and its resulting carbon fiber.