| Autor: |
Wang Chunhua, Wenzhi Wang, Hu Tianhui, Qibin Jiang, Yang Kejian, Rusheng Deng, Feng Hu, Hailiang Zhang |
| Rok vydání: |
2015 |
| Předmět: |
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| Zdroj: |
RSC Advances. 5:88382-88391 |
| ISSN: |
2046-2069 |
| DOI: |
10.1039/c5ra15598c |
| Popis: |
A novel star-branched nylon 6 with hexafunctional cyclotriphosphazene core was synthesized using hexa(4-carboxylphenoxy)cyclotriphosphazene (HCPCP) with six carboxyl groups as multifunctional agent in the hydrolytic ring-opening polymerization of e-caprolactam, and then used for the investigation of mechanical properties, crystallization and rheology behaviors. Star-branching structure and molecular weight have great effects on its properties. Compared with linear nylon 6, star-branched nylon 6 has lower relative viscosity and higher melt flow rate while its mechanical properties can be almost retained by the use of star-branching and an appropriate molecular weight. Research on crystallization behavior indicates that the degree of crystallinity (Xc) of star-branched nylon 6 decreases slightly, but its crystal structure still belongs to α form. The peak crystallization temperature (Tc) and crystallization rate (1/t1/2) of star-branched nylon 6 are significantly higher than that of linear nylon 6 because of heterogeneous nucleation induced by HCPCP core, which is beneficial for the use of rapid molding process. As the molecular weight increases, the Tc and 1/t1/2 of star-branched nylon 6 first increase and then decrease. Capillary rheometer measurement exhibits that the shear viscosity of star-branched nylon 6 decreases with decreasing molecular weight, and the shear viscosity of star-branched nylon 6 with an appropriate molecular weight shows a low value and little or no sensitivity to shear rate and temperature. Such rheology behavior allows for processing at low temperature and low pressure and reduces system cost. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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