A NEUTRON-SCATTERING STUDY OF POLYETHYLENE DEFORMED BY ROLLING

Polyethylene mixed crystal mats have been studied after rolling at roo m temperature to roll ratios up to 2.5, using the LOQ instrument at th e ISIS pulsed neutron source (RAL, Chilton). Radius of gyration measur ements for vertical (R(v)) and horizontal (R(H)) sectors, where the ve rtical sector includes the roll direction, show that R(H) is virtually unchanged by rolling, whereas R(V) is increased significantly. Combin ed with an unchanged intensity from extrapolation to zero angle, these results indicate the absence of local melting during deformation. Int ermediate angle measurements show a decrease in intensity, while the ' sheet-like' form of the scattering is retained. This is consistent wit h the breakup of lamellae into progressively smaller blocks, within wh ich the original stem arrangement is preserved.