Prominently Promoting the Formation of Poly(butylene adipate) α-Form Crystals by Coalescing from Inclusion Complex
We successfully use a co-precipitation method to prepare inclusion complex between poly(butylene adipate) (PBA) chains (guest component) and urea molecules (host component). The PBA/urea inclusion complex is confirmed to adopt a hexagonal crystal modification with lattice parameters of a = 8.14 Å and c = 10.92 Å, and the interaction between PBA chains and urea is van der Waals force. The singly isolated PBA chains are suggested to take some gauche conformation, which is different from the all-trans conformation in β-form PBA. Furthermore, we employ the isolated PBA chains which are uniformly pre-established in a specific conformation in urea channels to regulate the crystal form of PBA for the first time. After removing the host urea molecules, the coalesced PBA chains are found to solely crystallize into α-form crystals at different coalescing temperatures. By comparing the FTIR spectra, it is found that PBA chains in inclusion complex plausibly contain some similar conformers as those in α-form crystal, which is suggested to be the intrinsic reason for the sole formation of α-form crystals. This research proves that inclusion complex can be used as a very effective method to regulate polymorphism of semi-crystalline polymers.
KeywordsPoly(butylene adipate) Inclusion complex Polymorphism Chain conformation
Unable to display preview. Download preview PDF.
This work was financially supported by the National Natural Science Foundation of China (No. 21674128) and China University of Petroleum (Beijing).
- 11.Liang, R.; Chen, Y. C.; Zhang, C. Q.; Yin, J.; Liu, X. L.; Wang, L. K.; Kong, R.; Feng, X.; Yang, J. J. Crystallization behavior of biodegradable poly(ethylene adipate) modulated by a benign nucleating agent: Zinc phenylphosphonate. Chinese J. Polym. Sci. 2017, 35(sn4), 558–568.CrossRefGoogle Scholar
- 13.Yang, J.; Liang, R.; Chen, Y.; Zhang, C.; Zhang, R.; Wang, X.; Kong, R.; Chen, Q. Using a self-assemblable nucleating agent to tailor crystallization behavior, crystal morphology, polymorphic crystalline structure, and biodegradability of poly(1,4-butylene adipate). Ind. Eng. Chem. Res. 2017, 56(28), 7910–7919.CrossRefGoogle Scholar
- 16.Wang, H. J.; Feng, H. P.; Wang, X. C.; Guo, P. Y.; Zhao, T. S.; Ren, L. F.; Qiang, X. H.; Xiang, Y. H.; Yan, C. Effects of crystallization temperature and blend ratio on the crystal structure of poly(butylene adipate) in the poly(butylene adipate)/poly(butylene succinate) blends. Chinese J. Polym. Sci. 2014, 32(4), 488–496.CrossRefGoogle Scholar