The Effect of Molecular Chain Entanglement Regulated by Different Shear Conditions on Stereocomplex Crystallization in the PLLA/PDLA Blend

In order to investigate the effect of molecular chain entanglement regulated by different shear conditions on stereocomplex crystallization in the PLLA/PDLA blend, a rotary rheometer was used to apply shear fields. Subsequently, the rheological behavior and crystallization performance of the sheared sample were discussed in detail. The results indicate that all of the shear modes can achieve the disentanglement of the sample molecular chains, thus promoting the formation of stereocomplex crystals (SCs) in the system. The degree of chain disentanglement and the corresponding SC content in linear shear and high-strain large amplitude oscillatory shear (LAOS) samples are both higher than those in constant shear and low-strain LAOS samples, respectively. In addition, as the shear temperature decreases, the content of SCs increases in the same shear mode. All of these results provide a more detailed theoretical basis in the future for improving the SC content in the PLLA/PDLA blend.