Crystal transition and thermal behavior of Nylon 12
Ma Ning,
Liu Wentao,
Ma Lili,
He Suqin,
Liu Hao,
Zhang Zhenya,
Sun Aihua,
Huang Miaoming,
Zhu Chengshen
Affiliations
Ma Ning
School of Materials Science and Engineering, Zhengzhou University, No. 100 Science Avenue, Zhengzhou, Henan, 450001, P. R. China
Liu Wentao
School of Materials Science and Engineering, Zhengzhou University, No. 100 Science Avenue, Zhengzhou, Henan, 450001, P. R. China
Ma Lili
School of Materials Science and Engineering, Zhengzhou University, No. 100 Science Avenue, Zhengzhou, Henan, 450001, P. R. China
He Suqin
School of Materials Science and Engineering, Zhengzhou University, No. 100 Science Avenue, Zhengzhou, Henan, 450001, P. R. China
Liu Hao
School of Materials Science and Engineering, Zhengzhou University, No. 100 Science Avenue, Zhengzhou, Henan, 450001, P. R. China
Zhang Zhenya
Isotope Institute Co., Ltd., Henan Academy of Sciences, Zhengzhou 450015, China
Sun Aihua
Key Laboratory of Additive Manufacturing Material of Zhejiang Province, Department of Functional Materials and Nano-Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 1219 Zhongguan West Road, Ningbo 315201, China
Huang Miaoming
School of Materials Science and Engineering, Zhengzhou University, No. 100 Science Avenue, Zhengzhou, Henan, 450001, P. R. China
Zhu Chengshen
School of Materials Science and Engineering, Zhengzhou University, No. 100 Science Avenue, Zhengzhou, Henan, 450001, P. R. China
The polyamide 12 (PA12) with different crystal forms is prepared with three crystallization paths. The crystal structures and corresponding thermal properties are systematically investigated. The results reveal that an α-form and a mixed (α + γ)-form of PA12 can be obtained by casting at 30°C and (40–80°C), respectively. Meanwhile, the γ-form of PA12 can be obtained by both casting at 90°C and slow melt cooling. However, the γ′-form is obtained only by melt quenching. Both the γ and γ′ forms of PA12 exhibit a single melting peak, whereas the α-form exhibits two melting peaks. The higher peak is attributed to the melting of γ-PA12, which originates from the melting–recrystallization of the α-PA12. It is found that the tensile properties of PA12 depend on the crystal forms. Both the γ and γ′-PA12 are strong and tough polymer materials, while α-PA12 is a strong but brittle polymer material.
