433978-54-2Relevant articles and documents
The synthesis and characterisation of reactive poly(p-phenylene terephthalamide)s: A route towards compression stable aramid fibres
Knijnenberg, Alwin,Bos, Johan,Dingemans, Theo J.
experimental part, p. 1887 - 1897 (2011/11/14)
Herein we report on the synthesis of reactive poly(p-phenylene terephthalamide) (PPTA) oligomers and the preparation and characterisation of aramid fibres thereof. Methacrylate and maleimide reactive end-groups were found to be sufficiently stable in H2SO4 at 85?°C and they were used to prepare reactive PPTA oligomers. Lyotropic spin-dopes could be prepared with up to 20?wt% of reactive oligomer (Mn?=?3900?g?mol-1) and this modification did not interfere with the fibre spinning process and had no effect on the fibre tensile properties. The as-spun fibres did indeed show a modest (+0.1?GPa) improvement in compression strength. A high temperature treatment at 380?°C resulted in fibres which all show a significant increase in compressive strength over their as-spun precursors, i.e. from 0.7 to 0.9?GPa. When fibres were treated at 430?°C the compression values of the oligomer-modified fibres dropped somewhat, whereas unmodified PPTA displayed a compressive strength of 1.1?GPa. Other favourable fibre properties such as modulus and tenacity were not compromised.
