US 11,905,370 B2
Method for synthesizing long carbon chain semi-aromatic nylon
Minying Liu, Zhengzhou (CN); Bingfeng Xue, Zhengzhou (CN); Peng Fu, Zhengzhou (CN); Zhe Cui, Zhengzhou (CN); Xiaomeng Zhang, Zhengzhou (CN); Wei Zhao, Zhengzhou (CN); Xinchang Pang, Zhengzhou (CN); and Qingxiang Zhao, Zhengzhou (CN)
Assigned to Zhengzhou University, Zhengzhou (CN)
Filed by Zhengzhou University, Zhengzhou (CN)
Filed on Sep. 17, 2021, as Appl. No. 17/477,927.
Claims priority of application No. 202011246904.4 (CN), filed on Nov. 10, 2020.
Prior Publication US 2022/0145007 A1, May 12, 2022
Int. Cl. C08G 69/30 (2006.01); C08G 69/06 (2006.01); C08G 69/26 (2006.01); C08L 77/00 (2006.01)
CPC C08G 69/30 (2013.01) [C08G 69/06 (2013.01); C08G 69/26 (2013.01); C08L 77/00 (2013.01)] 16 Claims
 
1. A method for synthesizing a long carbon chain semi-aromatic nylon, wherein the method comprises:
mixing a wet powdery nylon salt, an antioxidant, a catalyst, a surfactant, and pellets and carrying out a one-step solid state polymerization under dynamic mixing to obtain a powdery nylon,
wherein the wet powdery nylon salt has a solvent content of 5-40% wt, and is prepared by salt-forming reaction of terephthalic acid and a long carbon chain diamine with 10-14 carbon atoms in the solvent,
wherein the pellets promote stirring and mixing of materials and reduce sticking of materials to a wall under dynamic mixing,
wherein the one-step solid state polymerization includes pre-solid state polymerization and post-solid state polymerization; in the pre-solid state polymerization, gradually increasing temperature of the system from 150-190° C. to 180-220° C., ensuring the nylon salt and the prepolymer not to be molten, and increasing the solvent vapor pressure to 1.00-2.20 MPa during the period; in the post-solid state polymerization, gradually reducing the system pressure to vacuum and holding for at least 1 h; the temperature of the post-solid state polymerization should not be lower than the termination temperature of the pre-solid state polymerization; and
wherein, in the pre-solid state polymerization, gradually increasing the temperature from 150-190° C. to 180-220° C. includes: holding the temperature at 150-190° C. for 0.5-2 h, then increasing the temperature to 180-220° C. at a rate of 5-10° C. for 0.5-1 h, and holding for 0.5-2 h.