Abstract:
Rigid polylactic acid (PLA) foams fabricated via thermally induced phase separation (TIPS) utilizing a ternary solution of PLA, Tetrahydrofuran (THF), and water. The PLA gels were stabilized mechanically by the substituting of the THF/water solvent mixture with ethanol as non-solvent and subsequently vacuum dried. A comprehensive characterization of PLA foams was achieved by Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD) and Brunauer-Emmett-Teller (BET) analyses. The BET area obtained in the PLA foam is up to 18.76 m2/g. The Response Surface Methodology (RSM) was utilized to assess the impacts of four independent variables (polymer concentration, solvent composition, quench temperature, and aging time) on the pore size and density of PLA foam. The experimental findings demonstrated that the fabrication parameters could be fine-tuned to govern the morphology of the pores, comprising their size and density. The optimal values of parameters for cell size were identified by RSM to be 8.96 (wt%), 91.60 (w/w), 5.50 °C, and 3.86 h for the optimum cell size of 37.96 µm (37.78 by Genetic Algorithm). Optimum density by RSM 88.88 mgr/cm3 (88.38 mgr/cm3 by Genetic Algorithm) was obtained at 5.00 (wt%), 89.33 (w/w), 14.40 °C and 2.65 h.
摘要:
通过热诱导相分离(TIPS)制造的刚性聚乳酸(PLA)泡沫,利用PLA的三元溶液,四氢呋喃(THF),和水。通过用乙醇作为非溶剂代替THF/水溶剂混合物机械地稳定PLA凝胶,随后真空干燥。通过扫描电子显微镜(SEM)对PLA泡沫进行了全面表征,X射线衍射(XRD)和Brunauer-Emmett-Teller(BET)分析。在PLA泡沫中获得的BET面积高达18.76m2/g。响应面方法(RSM)用于评估四个独立变量(聚合物浓度,溶剂组合物,淬火温度,和老化时间)对PLA泡沫的孔径和密度的影响。实验结果表明,可以微调制造参数以控制孔的形态,包括它们的大小和密度。细胞大小的参数的最佳值由RSM确定为8.96(重量%),91.60(w/w),5.50°C,和3.86h的最佳细胞大小为37.96µm(遗传算法为37.78)。通过RSM的最佳密度88.88mgr/cm3(通过遗传算法88.38mgr/cm3)在5.00(wt%)获得,89.33(w/w),14.40°C和2.65h。