Extension decelerated crystallization in γ-irradiated isotactic polypropylene: The role of asymmetric chain relaxation

Cyclic tensile machine with wide speed range for in situ neutron/X-ray scattering study on elastomers

A tensile machine is designed for in situ scattering investigation of elastomers in the cyclic tensile process. The specimen is stretched by two linearly moving clamps in the opposite direction; thus, the center of the specimen is kept stationary during the tensile test. With this configuration, either X-ray scattering or neutron scattering can be carried out easily. A high speed direct current motor is used to drive the machine, providing a wide tensile speed range from 1.28 × 10^-3 mm/s to 102.4 mm/s. Cyclic tension is achieved by program controlled motor rotation, and the engineering stress-strain curve can be saved automatically in each cycle. Moreover, an independent displacement sensor is used to check the possible accumulative error of position during cyclic tension. The orientation change of multiwall carbon nanotube filled silicon rubber is investigated by small angle neutron scattering to test the machine, which shows that the machine is capable of combining the cyclic tensile test with in situ scattering measurement.