The solvent annealing effect of ultrahigh molecular weight polyethylene fiber was studied. These fibers were analyzed using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and x-ray diffraction (XRD).To improve the efficiency, the solvent annealing temperature is close to the melting point and the fiber can retain high modulus at a certain annealing temperature and time range. The crystallinity result shows a similar changing pattern with tensile property. It is suggested that the fiber with the solvent has high chain mobility and the amorphous part can be re-swollen and disentangled to enhance the recrystallization between the microfiber structures, which can cause the formation of interlocking structure. The interlocking structure may be the key fac...[ Read more ]

The solvent annealing effect of ultrahigh molecular weight polyethylene fiber was studied. These fibers were analyzed using scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and x-ray diffraction (XRD).To improve the efficiency, the solvent annealing temperature is close to the melting point and the fiber can retain high modulus at a certain annealing temperature and time range. The crystallinity result shows a similar changing pattern with tensile property. It is suggested that the fiber with the solvent has high chain mobility and the amorphous part can be re-swollen and disentangled to enhance the recrystallization between the microfiber structures, which can cause the formation of interlocking structure. The interlocking structure may be the key factor for the improvement of tensile property.

Moreover, two different annealing methods -- direct and post -- were applied to study the effect of fiber relaxation on annealing. It shows that direct annealing can achieve better tensile modulus in certain condition compared the post annealing, implying that the relaxation of the fiber has a significant effect on the fiber structure during annealing. However, with a higher annealing temperature and longer annealing time, the fibrous crystal may dissolve with the solvent and become disoriented. The recrystallization process and the dissolving process are two competitive processing.