Quispe-Dominguez Roger, Naseem Sajid, Leuteritz Andreas, Kuehnert Ines
Leibniz-Institut für Polymerforschung Dresden e.V. Dresden Germany
RSC Adv. 2019 Jan 2;9(2):658-667. doi: 10.1039/c8ra08780f.
This research work is based on the comparison of the mixing phenomena of magnesium-aluminum (MgAl) layered double hydroxides (LDHs) intercalated by dodecylbenzene sulfonate (MgAl-DBS) in poly(lactic acid) (PLA). Two mixing techniques were used to compare the dispersion of LDHs in PLA such as sonication-assisted masterbatch (SAM) melt mixing and direct melting (DM) methods. MgAl LDHs synthesized by the urea hydrolysis method and intercalated with DBS anions using anion exchange reaction and were used in different ratios in PLA (1.25, 2.5, and 5 wt%). MgAl LDHs and their anion intercalation were studied by the X-ray diffraction analysis (XRD) method. Different properties of LDH/PLA composites were compared to analyze the effect of these mixing techniques. Dispersion and exfoliation of LDHs in PLA were investigated by X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). Influences on the rheological properties were evaluated by analyzing the complex viscosities (*), storage modulus (') and loss modulus ('') by using a rheometer. The thermal properties, thermal stability and effect on crystallinity of composites made with the two mixing techniques were analyzed by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) respectively. The mixing mechanism and amount of MgAl-DBS LDHs have a notable effect on the properties of PLA composites with sonication-assisted masterbatch melt mixing techniques giving better dispersion of LDHs in PLA composites as compared to direct melt mixing.
本研究工作基于对十二烷基苯磺酸盐插层的镁铝（MgAl）层状双氢氧化物（LDHs）（MgAl-DBS）在聚乳酸（PLA）中的混合现象的比较。采用了两种混合技术来比较LDHs在PLA中的分散情况，如超声辅助母料（SAM）熔融混合和直接熔融（DM）方法。通过尿素水解法合成MgAl LDHs，并利用阴离子交换反应将其与DBS阴离子插层，然后以不同比例（1.25、2.5和5 wt%）用于PLA中。采用X射线衍射分析（XRD）方法研究了MgAl LDHs及其阴离子插层情况。比较了LDH/PLA复合材料的不同性能，以分析这些混合技术的效果。通过X射线衍射分析（XRD）和透射电子显微镜（TEM）研究了LDHs在PLA中的分散和剥离情况。使用流变仪分析复数粘度（*）、储能模量（'）和损耗模量（''），评估对流变性能的影响。分别通过热重分析（TGA）和差示扫描量热法（DSC）分析了两种混合技术制备的复合材料的热性能、热稳定性及对结晶度的影响。混合机理和MgAl-DBS LDHs的用量对PLA复合材料的性能有显著影响，与直接熔融混合相比，超声辅助母料熔融混合技术能使LDHs在PLA复合材料中得到更好的分散。
