用于FDM的PLA共混改性

采用酰胺成核剂(NT–C)和聚乙二醇(PEG2000)对聚乳酸(PLA)进行熔融共混改性,制备了用于3D打印的PLA/NT–C/PEG2000共混物,并在200℃的温度下通过熔融沉积成型(FDM)工艺制备了共混物FDM打印件。研究了NT–C的用量对PLA/NT–C打印件结晶性能的影响,并在此基础上研究了PEG2000用量对共混物流变性能、共混物打印件的结晶性能和力学性能的影响。差示扫描量热分析表明NT–C可在一定程度上提高PLA/NT–C打印件的结晶度,一定用量的PEG2000的添加进一步提高了共混物打印件的结晶性能,当NT–C和PEG2000的质量分数分别为2%和5%时,打印件的结晶度达到17.1%,相比PLA提高了12倍;流变性能测试表明PEG2000提高了共混物的熔体流动速率,降低了共混物储能模量和损耗模量对温度的依赖性,扩宽了PLA在FDM工艺中的成型温度;力学性能测试表明PEG2000显著提高了PLA/NT–C/PEG2000共混物的缺口冲击强度,降低了打印中断丝的几率,FDM打印件弯曲和拉伸强度相比于PLA也有显著提高,当NT–C和PEG2000的质量分数分别为2%和5%时,打印件的弯曲和拉伸强度分别达到了注塑件的80%和70%以上,扩宽了PLA在FDM中应用。

Blending Modification of PLA Used for Fused Deposition Modeling

Amide nucleating agent (NT-C) and polyethylene glycol 2000 (PEG2000) were used for modification of polylactic acid (PLA) by melt blending,then the PLA/NT-C/PEG2000 blends used for 3D printing were prepared. Print parts of the blends were prepared through fused deposition modeling (FDM) under 200 ℃ . The effects of NT-C contents on the crystallization prop-erties of PLA/NT-C print parts were studied,on this basis,the influences of PEG2000 contents on rheological properties of the blends,crystallization properties and mechanical properties of the blend print parts were studied. DSC analysis showes that NT-C can improve the crystallinity of PLA/NT-C print parts to some extent and the addition of PEG2000 with a certain contents can fur-ther improve the crystallinity,when the mass fraction of NT-C and PEG2000 is 2% and 5% respectively,the crystallinity reaches 17.1% and is improved by 12 times higher than PLA. The rheological properties tests show that PEG2000 improves the melt flow rate of the blend,the temperature dependency of the blend's storage modulus and loss modulus decreases,which broadens PLA 's molding temperature in the FDM processing. Mechanical properties tests show that the notched impact strength of the blend is sig-nificantly improved with addition of PEG2000,which reduces the risk of the interrupt silk when printing process,flexural and tensile strength of the blend print parts are also significantly improved compared with PLA,when adding 2% NT-C and 5% PEG2000,the flexural and tensile strength can reache more than 80% and 70% of those of injection parts separately,which broadens PLA's appli-cation in the FDM.