- 學位論文
探討PBAT聚酯之單體組成與聚縮合條件對其物性與生分解性之研究
Investigation of polycondensation conditions and monomer compositions on the physical and lipase-degradable properties of poly(butylene adipate-co-terephthalate)
摘要
本研究以己二酸（adipic acid, AA）、對苯二甲酸二甲酯（dimethyl terephthalate, DMT）、1,4-丁二醇（1,4-butanediol, BDO）等單體藉由轉酯化反應（transesterification）及聚縮合反應（polycondensation）合成生物可分解性聚酯Poly(butylenes adipate-co-terephthalate) (PBAT)。實驗過程中，探討縮合反應溫度、1,4丁二醇對應二元酸總莫耳數添加比例及不同二元酸單體莫耳百分比變動對所合成之PBAT聚酯之本質黏度（intrinsic viscosity, [η]）、熱性質、機械性質與生物分解性之影響。實驗結果發現，當二元酸單體比例為AA/(AA+DMT)＝50 mol%、二元醇濃度BDO/(AA+DMT)＝1.2 mol/mol、催化劑（tetrabutyl titanate, Ti(Obu)4）濃度為0.97 mmol/mol (AA+DMT)時，聚縮合反應溫度260 ℃所合成之PBAT之共聚酯[η]值可達0.6 dL/g為聚縮合反應溫度系列中最高。相對所得之共聚酯之熔點（Tm）為145.5 ℃、熱裂解溫度（Td）為368.6 ℃、結晶度（crystallinity）為15.2 %。當AA/(AA+DMT)＝70 mol%時，所測得共聚酯之Tm為85.3 ℃、而降低AA/(AA+DMT)＝30 mol%，聚酯Tm上升至179.3 ℃。相對於Td變動由348.7 ℃上升至373.5 ℃。同時聚酯結晶度變化亦由AA/(AA+DMT)＝70 mol%時的4.32 %，而隨著AA單體莫百分比下降至30 mol%時上升至40.8 %；此外機械性質測試結果顯示，所合成之共聚酯之拉伸強度（tensile strength）於AA/(AA+DMT)＝30 mol%時，其測得拉伸強度為20.1 MPa為最高；而延伸率（elongation）以則以AA/(AA+DMT)＝50 mol%時可達最大150 %；楊氏模數（Young’s modulus）的表現則以AA/(AA+DMT)＝30 mol%時可達最大值608.6 MPa。而由酵素水解系統中的生物可分解性測試結果發現，隨著AA/(AA+DMT)比例增加，其所測得生物分解的速率越快，其中以AA/(AA+DMT)＝70 mol%時最快，於分解測試二週後可達100 %。
並列摘要
In this study, a series of aliphatic-aromatic coplyesters of poly(butylene adipate-co-butylene terephthalate) (PBAT) was prepared from adipic acid (AA), dimethyl terephthalate (DMT), and 1,4-butanediol(BDO) by catalyzed transesterification. The experiment investigated the different temperature of polycondensation, molar ratio of BDO/(AA+DMT), and AA/(AA+DMT) on the physical and lipase-degradable properties of PBAT. The first part of experiment investigated the effects of different temperature and molar ratio of BDO/(AA+DMT). The results showed the best polycondensation for high [η] (0.6 dL/g), proper melting point (145.5 ℃), high decomposition point (368.6 ℃) and proper crystallinity (15.2 %) reached at temperature of 260 ℃, BDO/(AA+DMT) = 1.2 mol/mol with AA/(AA+DMT) = 50 mol%, and 0.97 mmol/mol (AA+DMT) of tetrabutyl titanate (Ti(Obu)4). The second part of experiment investigated the best molar percentage of AA/(AA+DMT) for the polymer properties and biodegradability. The results shown that Tm, Td and crystallinity up to 179.3 ℃ , 373.5 ℃ and 40.8 % respectively at AA/(AA+DMT) = 30 mol%. The maximum tensile strength of 20.1 MPa was reached at AA/(AA+DMT) = 30 mol%. The maximum elongation at break of 150 % reached at AA/(AA+DMT) = 50 mol%. The maximum Young's modulus of 608.6 MPa reached at AA/(AA+DMT) = 30 mol%. The fastest lipase-decomposition rate of PBAT reached 100 % at 2 weeks for samples of molar ratio AA/(AA+DMT) = 70 mol%.