Polyamide 6(PA6)powder with high relative viscosity of 22.47 was prepared via anionic slurry polymerization

and then different PA6 gels were gained by dissolving PA6 powder in formic acid using calcium chloride (CaCl2)as complex agent.X-ray photoelectron spectroscopy(XPS)was used to characterize the bonding energy of inside electrons of pure PA6

CaCl2 and PA6/CaCl2 complexes

and Fourier transform infrared spectroscopy (FTIR)was performed to analyze the changes of the wave number of NH

amide Ⅰ and amide Ⅱ related to hydrogen bond in PA6/CaCl2 complexes.Based on the experiment results

a complexation mechanism was proposed to explain the reaction between amide group and CaCl2.Calcium cations coordinated with the oxygen atom of carbonyl group

which weakened the hydrogen bonding between the molecular chains of PA6 and released the free N—H group

so the N—H group coordinated with chloride anions to form the hydrogen bonding.There was no complexation between calcium cations and the nitrogen atom as the mole ratio of calcium chloride to the unit of amide group in PA6 was 0.2.The coordination number between CaCl2 and the amide groups was predicted to be four or six by conductivity measurements.