Tensile behaviour of polyethylene and poly(p-xylylene) fibres

This thesis deals with the tensile behaviour of fibres prepared from high molecular weight polymers.The tensile strength of a polymeric fibre is in general much lower than the corresponding theoretical value. In case of ultra-high molecular weight polyethylene (UHMWPE), fibres can be prepared by gel-spinning and subsequent hot-drawing having a tensile strength of 7.2 GPa, whereas the theoretical tensile strength is about 30 GPa. Although such fibres are relatively perfect with respect to crystallinity and orientation of the chains, there must be intrinsic imperfections that determine the tensile strength.