An organically modified montmorillonite/nylon-12 composite powder for selective laser sintering
An organically modified montmorillonite/nylon-12 composite powder for selective laser sintering
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DOI：
10.1108/13552541111098608
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发表时间：
2011-01-01
影响因子：
3.9
通讯作者：
Liu, J. H.
中科院分区：
文献类型：
--
作者：
Yan, C. Z.;Shi, Y. S.;Liu, J. H.
目的-本文的目的是使用有机改性蒙脱土（OMMT）增强尼龙-12的选择性激光烧结（SLS）部件。设计/方法/途径-开发溶解-沉淀过程以制备OMMT/尼龙-12复合粉末（3wt%OMMT）。使用X射线衍射（XRD）来表征纳米结构特征。通过扫描电镜（SEM）观察了OMMT在尼龙12基体中的分散情况。采用差示扫描量热法（DSC）和热重分析法（TGA）研究了有机蒙脱土（OMMT）对尼龙12热性能的影响。结果-X射线衍射和扫描电镜结果表明，在溶解-沉淀过程中，OMMT被尼龙12分子链插层并均匀分散在尼龙12基体中，形成了OMMT/尼龙12插层纳米复合材料。DSC和TGA结果表明，OMMT能提高尼龙12的熔融焓、相对结晶含量、结晶温度和热稳定性。用该复合粉末制备的SLS试样的拉伸强度、拉伸模量、弯曲强度、弯曲模量和冲击强度分别比纯尼龙12 SLS试样提高23.2%、31.7%、18.7%、32.4%和8.4%，而断裂伸长率下降了17.5%。研究限制/影响-从XRD分析结果可以看出，在本工作中形成了插层型纳米复合材料。通过透射电子显微镜观察材料的纳米结构还有待进一步研究。独创性/价值--采用溶解-沉淀法制备了用于SLS工艺的OMMT/尼龙-12复合粉体。在制备过程中，OMMT可以插层到尼龙12分子链之间，并均匀分散在尼龙12基体中，形成OMMT/尼龙12插层纳米复合材料。因此，尼龙-12 SLS制件的力学性能和热性能得到了提高。
Purpose - The purpose of this paper is to reinforce the selective laser sintering (SLS) parts of nylon-12 using organically modified montmorillonite (OMMT).Design/methodology/approach - A dissolution-precipitation process is developed to prepare an OMMT/nylon-12 composite powder (3 wt% OMMT). X-ray diffraction (XRD) was used to characterize nanostructure features. The dispersion of OMMT in the nylon-12 matrix was observed by scanning electron microscope (SEM). The effect of OMMT on the thermal properties of nylon-12 was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The mechanical properties of the SLS parts made from the composite powder and neat nylon-12 powder were measured and compared.Findings - The X-ray diffraction and SEM results indicate that the OMMT is intercalated by nylon-12 molecular chains and uniformly dispersed in the nylon-12 matrix during the dissolution-precipitation process, and thus the OMMT/nylon-12 intercalated nanocomposites are formed. The DSC and TGA results show that the OMMT can increase the melting enthalpy, relative crystalline content, crystallization temperature and thermal stability of nylon-12. The tensile strength, tensile modulus, flexural strength, flexural modulus and impact strength of the SLS specimens made from the composite powder are 23.2, 31.7, 18.7, 32.4 and 8.4 percent higher than those of neat nylon-12 SLS specimens, respectively, while the elongation at break decreases by 17.5 percent.Research limitations/implications - The conclusion of forming intercalated nanocomposites was drawn from the XRD results in the present work. Further work should be done to observe the nanostructures of the materials by transmission electron microscope.Originality/value - A dissolution-precipitation process was used to prepare OMMT/nylon-12 composite powders for SLS process. During the preparation process the OMMT could be intercalated by nylon-12 molecular chains and uniformly dispersed in the nylon-12 matrix, thus forming the OMMT/nylon-12 intercalated nanocomposites. Therefore, the mechanical and thermal properties of nylon-12 SLS parts were enhanced.