n-SiO_2对PA12涂层非等温结晶速率及成核活度系数的影响

Effect of Silicon Dioxide on Non-Isothermal Crystallization Rate Coefficient and Nucleation Activity of PA12 Coating

利用火焰喷涂技术制备了聚酰胺12(PA12)及PA12/纳米Si O2(n-Si O2)复合涂层,采用差示扫描量热法(DSC)对涂层的非等温结晶性能进行了分析,探讨了n-Si O2对PA12涂层的结晶速率常数及成核活度系数的影响。结果表明,当n-Si O2的添加量在0.5%～2.5%(质量分数,下同)时,PA12/n-Si O2复合涂层的结晶速率常数和成核活度系数均大于纯PA12涂层,说明PA12/n-Si O2复合涂层更容易结晶;n-Si O2在PA12基体中有明显的成核剂作用;当n-Si O2添加量1.5%时,成核活度系数最小为0.936,成核活度最大,成核作用最明显。

The non-isothermal crystallization properties of polyamide 12（PA12） coating and PA12/n-SiO2 composite coatings which were prepared by flame sprayed were investigated by differential scanning calorimeter（DSC） at various cooling rates.The effects of silicon dioxide on non-isothermal crystallization rate coefficient（CRC） and nucleation activity of PA12 coating were researched.The results show that when the composite coatings contain n-SiO2 from 0.5% to 2.5%,the CRC is lager than that of the pure coating and the nucleation activity of PA12/n-SiO2 composite coatings is less than that of the pure coating.The values of CRC and the nucleation activity show that PA12/n-SiO2 composite coatings have higher crystallization rate and easier crystallization behavior than the pure coating at a given cooling rate,which suggests that nano-SiO2 acts as nucleation agents in the PA12 matrix.