The conditions for the formation of spherical micropowders of polyamide (PA) 12 in ethanol were studied. By ob-serving the shape of the micropowders obtained at different cooling rates,it was concluded that the necessary condition for the for-mation of spherical crystals of PA12 in ethanol is that the cooling rate cannot exceed 0.5℃/min. Further the experiments show that the heat preservation during the nucleation stage makes the particle size distribution of the obtainedfine powder more concentrated, and with the extension of the holding time,sphericalfine powders of different particle sizes of about 30–60μm are obtained. The similarities and differences between PA12 powders obtained in ethanol and DMF are compared,and the results show thatfiner spher-icalfine powders are more easily obtained in DMF.%研究了尼龙(PA)12在乙醇中形成球形微粉的条件,通过对不同降温速率下得到的微粉形状的观察,得出了PA12在乙醇中形成球状结晶的必要条件是降温速率不能超过0.5℃/min.进一步的实验表明,在成核阶段的保温使获得微粉的粒径分布更为集中,且通过延长保温时间,获得了30～60μm左右的不同粒径大小的球形微粉.还对比了PA12在乙醇与二甲基甲酰胺(DMF)两种不同溶剂中获得微粉颗粒的异同,结果表明,在DMF中更易获得更细的球形微粉.
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