Study on crystallization of poly (L-lactic acid) nucleated with p-tert-butylcalix[4]arene inclusion complex

In this paper, four inclusion complexes were obtained by recrystallizing p-tert-butylcalix[4]arene (tBC4) from toluene, o-xylene, m-xylene and p-xylene. Then, the effects of tBC4 inclusion complexes on crystallization behavior of poly (L-lactic acid) (PLLA) were investigated with differential scanning calorimeter and polarized optical microscopy. The results showed that the crystallization peak temperature of PLLA nucleated by tBC4 inclusion complexes increased 7℃, which indicated that these compounds owned the nucleation ability for PLLA. After suffering high temperature, crystal structures of four inclusion complexes reverted to nearly the same. Therefore, all these inclusion complexes showed the same nucleation ability. Crystallization morphologies of PLLA and nucleated PLLA were studied by means of polarizing optical microscopy, indicating that the addition of nucleating agent can decrease PLLA spherulite size without changing its growth pattern. © All right reserved.