Analysis of Molecular Aggregation Structures of Fully Aromatic and Semialiphatic Polyimide Films with Synchrotron Grazing Incidence Wide-Angle X-ray Scattering

作者：Wakita Junji; Jin Sangwoo; Shin Tae Joo; Ree Moonhor^*; Ando Shinji

来源：Macromolecules, 2010, 43(4): 1930-1941.

DOI：10.1021/ma902252y

The intermolecular aggregation structures of fully aromatic polyimides (Ar-PIs) prepared from pyromillitic dianhydride (PMDA) and those of semialiphatic polyimides (Al-PIs) from 4,4'-diamino-cyclohexylmethane (DCHM) were characterized by a grazing incidence wide-angle X-ray scattering (GIWAXS) technique. The aggregation structures of both Ar- and Al-PI thin films formed on Si substrates were identified as a mixture of it liquid-crystalline-like ordered domain and an amorphous matrix. For Ar-PIs whose glass transition temperatures (T(g)) are higher than the imidization temperature (T(i)), the aggregation structures are significantly influenced by the three-dimensional structures of the PI chain. Rodlike molecular structures with high planarity are prerequisites for the growth of ordered domains of Ar-PIs, whereas an Ar-PI having a bent and nonplanar structure displays the highest intensities of an amorphous halo. In addition, the bulky -CF(3) groups in the diamine moiety increase the interchain distance in the ordered domains. On the other hand, for Al-PIs whose T(g)s arc lower than T(i), the degrees of interchain ordering in the ordered domains were higher than those of Ar-PIs, but the orientation of the ordered domains was decreased significantly by decreasing their T(g)s. This is due to the vigorous motion of PI chains during thermal imidization.

• 出版日期2010-2-23