本研究利用二苯亞甲基山梨醇(DBS)及聚乳酸(PLLA)以高溫熔融摻混法製備複合材料。本研究目的為利用二苯亞甲基山梨醇(DBS)以非溶劑之製備方式來改善聚乳酸(PLLA)之特性，研究主要分成二部份進行，一為藉由雙螺桿混煉機製備DBS/PLLA複合材料來探討物理性質分析及結晶行為分析，另一為先雙螺桿混煉機製備成複合材料再利用熱壓成型機製備成DBS/PLLA複合材料膜來進行結構與性質分析。 第一部份之混煉製成複合材料以流變分析結果可得知於熔融狀態下儲存模數G’、損失模數G”及複合黏度隨DBS之添加而有下降之趨勢，因DBS為一稀釋劑而導致黏度下降；由DSC結晶行為分析結果可觀察到DBS之添加促進PLLA結晶型態由不規整α’型態轉變為規整α型態。利用POM及DBS等溫結晶分析結果可觀察到於低溫時PLLA之結晶速率因DBS之添加導致表面自由能增加而有延後之趨勢，則於高溫處因DBS纖維無生成而導致結晶速率加速趨勢。 第二部份之複合材料以結構分析則可觀察到DBS纖維長於DBS/PLLA複合材料膜之表面及內部。由機械性質分析結果發現DBS之添加提升PLLA之剛性及結晶度，故導致抗張強度與斷裂伸長率呈現隨之下降趨勢。觀察接觸角吸水分析結果，發現DBS之添加能有效地改善PLLA疏水性質且提升其吸水量。 In this study, we preparation the complex polymer of 1, 3:2, 4-Dibenzylidene sorbitol (DBS)and Poly-L-lactic acid(PLLA) by a high temperature melt blended composites method. The purpose for the use of the non-solvent of DBS to prepare a way to improve PLLA characteristics of our study is divided into two parts. The one for the twin screw kneader were prepared by DBS / PLLA composite materials to analysis and these results explore the physical properties of the crystalline and characterization. The other is the pre-twin-screw compounding composites were prepared to re-use of thermoforming were prepared to DBS / PLLA composite membrane for structure and characteristic analysis. The fist analysis part of composite material rheology by the mixing process to observe the results that the storage modulus G'', loss modulus G" and the complex viscosity on the melt state with added DBS while the trend of the decline. Because DBS is a result of a diluent viscosity decreased. Crystallization behavior by the DSC analysis, we can be observed in the DBS added to promote crystallization of PLLA by the irregular patterns of α'' into regular patterns of α. By the POM and DSC isothermal crystallization results can be observed that the crystallization cycle of PLLA at low temperature crystallization by the addition of the DBS lead to an increase in surface free energy of PLLA and decreased the PLLA composite materials’ crystal growth rate. But the DBS fibers nongrowed at the high temperature crystallization that enhance PLLA composite materials’ crystal growth rate.
The second analysis part of the composite structural can be observed the DBS fibers longer than the surface and inside of the DBS / PLLA composite film. Analysis can found that the mechanical properties of the DBS add rigidity and to enhance the degree of crystallinity of PLLA, led to the tensile strength and elongation at break presented along with a downward trend. Observation of water contact angle analysis, that the addition of DBS can improve PLLA hydrophobic properties and enhance its absorption capacity.
