摘要
为了充分利用无机金属盐对聚酰胺结晶行为的调控作用,采用不同加工方法生产聚己二酰己二胺(PA66)/LiCl共混物,根据与PA66混合时LiCl的状态(LiCl水溶液或LiCl固体颗粒),分别得到母粒法-锂(YBL-Li)系列及一步法-锂(HY-Li)系列。实验结果表明,两组样品中LiCl均显著降低了PA66的结晶度、结晶温度与熔点,通过非等温结晶行为发现YBL-Li系列降低结晶速率的效果更为显著。含有Li离子的PA66储能模量、复数黏度均低于纯PA66。并且当Li离子含量较高时,与PA66形成的交联网络使熔体相应地在低频区出现新的平台。在宏观性能上,Li离子一定程度降低PA66的屈服强度、断裂伸长率,且随着含量增加加剧了材料的脆性。YBL-Li系列得益于Li离子的良好分散,在较高Li离子含量时,交联网络结构产生的缠结位点逐渐成为影响材料抵抗弹性形变能力的主导因素,使拉伸弹性模量高于纯PA66。而HY-Li系列对结晶性能的破坏以及Li离子分散不良,使得拉伸弹性模量随着Li离子含量的增加而递减。通过能量色散X射线能谱的点扫描与面扫描分析Cl离子的含量和分布,证实在相同的含量下YBL-Li系列中Li离子的分散优于HY-Li系列。
To utilize inorganic metal salts for modifying the crystallization behavior of polyamides,two series of polyhexamethylene adipamide(PA66)/LiCl blends were prepared via different processing methods,and were denoted as the masterbatch-Li(YBL-Li)series and the one-step-Li(HY-Li)series according to the state of LiCl mixed with PA66(LiCl aqueous solution or solid LiCl particles).The results indicate that both LiCl significantly reduces the crystallinity,crystallization temperature and melting point of PA66,and non-isothermal crystallization studies further reveal that the YBL-Li series exhibits a more pronounced effect on reducing the crystallization rate.The energy storage modulus and complex viscosity of PA66 containing Li ions are lower than those of neat PA66.Moreover,when Li ions contents is higher,cross-linked network formed with PA66 leads to the emergence of a plateau in the low-frequency region of the melt.In terms of macroscopic performance,Li ions reduce the yield strength and elongation at break of PA66 to a certain extent,and enhance the material brittleness with increasing Li ions contents.Benefiting from the good dispersion of Li ions,the YBL-Li series develops more entanglement points from the cross-linked network at higher contents,which gradually become the dominant factor in enhancing the resistance to elastic deformation,resulting in a higher tensile modulus than that of neat PA66.In contrast,the disruption of crystallization and poor dispersion of Li ions in the HY-Li series cause the tensile modulus to decrease with the increase of Li ion content.Analysis of the content and distribution of Cl ions by point-scan and mapping of energy dispersive spectroscopy confirm that the dispersion of Li ions of the YBL-Li series is superior to that of the HY-Li series at the same concentration.
作者
林洁龙
冯健
叶士兵
LIN Jielong;FENG Jian;YE Shibing(Shanghai Kingfa Sci.&Tech.Co.Ltd.,Shanghai 201714,China;Kingfa Sci.&Tech.Co.Ltd.,Guangzhou 510663,China)
出处
《工程塑料应用》
北大核心
2025年第11期78-85,共8页
Engineering Plastics Application
关键词
PA66
LICL
结晶行为
流变行为
拉伸性能
PA66
LiCl
crystallization behavior
rheological behavior
tensile property
