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Chen Y.-N.,Beijing Institute of Fashion Technology | Chen Y.,Key Laboratory of Clothing Materials RandD and Assessment
Journal of Beijing Institute of Clothing Technology (Natural Science Edition) | Year: 2010

Focused on the cotton fibre hydrolysis with dilute hydrochloric acid as catalyst. The form's change of cotton fiber was observed by SEM and the crystalline structure of that was determined by X-ray diffraction. Results showed that under the atmospheric conditions, thick hydrochloric acid mass fraction, high reaction temperature and long reaction time all could impromote the hydrolysis of cotton fibers effectively. The influence of the solid-liquid weight ratio on the hydrolysis reaction was proved to be compositive, and the hydrolysis reaction was along with the change of cotton fiber form and crystallinity. Under the experimental conditions, the best process parameters were obtained as the following; the mass ratio of hydrochloric acid is 9. 5 percent, the reaction temperature is 95 °C, and the solid-liquid weight ratio is 4: 100.

Xiong Z.,Key Laboratory of Clothing Materials RandD and Assessment | Li X.,Key Laboratory of Clothing Materials RandD and Assessment | Jia Q.,Key Laboratory of Clothing Materials RandD and Assessment | Fu Z.,Beijing Institute of Fashion Technology | Yang Z.,Beijing Institute of Fashion Technology
Acta Polymerica Sinica | Year: 2010

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/CaCl 2 complexes. Based on the experiment results, a complexation mechanism was proposed to explain the reaction between amide group and CaCl 2. 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.

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