- 學位論文
脂肪族聚酯與澱粉混煉之生物可分解性塑膠的擠壓加工探討
Investigation of extrusion process for the aliphatic polyester and starch compounded biodegradable plastics
摘要
本研究之第一部份以玉米澱粉、脂肪族聚酯poly(butylene succinate) (PBS)、甘油與水做為基礎配方，改變不同的塑化劑重量百分比，找出最適之塑化劑添加比例。抗張強度部分，當塑化劑添加比例為9 ％時，材料有最大抗張強度10.60 ± 0.10 MPa。伸長率部分，在塑化劑添加比例為11 %時，材料有最大伸長率87 ± 11 ％。楊氏模數方面，在塑化劑添加比例為10 %時，材料有最大楊氏模數435.0 ± 22.4 MPa。第一部分之研究顯示，此材料的塑化劑添加量約以10 ％為上限，超過10 ％的添加量時，只對伸長率有幫助，而其它機械性質則會降低。第二部分之實驗為了改善第一部分實驗材料的拉伸強度與延展性，乃進行23實驗設計而發現當塑化劑重量百分比14 ％，甘油與水的比例為4 : 1，PBS與玉米澱粉的比例為7 : 3時，其塑膠樣本的最高抗張強度可提升為13.43 ± 0.42 MPa，而且在伸長率方面可提升為256 ± 4 ％，約為第一部分實驗的最大伸長率樣本的3倍。第三部分實驗則以反應曲面法來設計實驗，採用三變數五層級之方法，探討甘油(A)、水(B)、玉米澱粉(C)的含量對於樣品機械性質的影響。而獲得抗張強度的數學預測模式為 。伸長率方面，由於數據受實驗誤差之影響，導致可預測性低，因此將數據以Log10轉換後再進行分析，而求得較佳的數學預測模式為 。楊氏模數方面，亦將數據進行倒數平方數轉換而得數學預測模式為 。本研究結果顯示PBS可取代一些價格昂貴的可分解性聚酯而應用於澱粉混煉塑膠之研究中。
並列摘要
In the first part of this study, corn starch, poly(butylene succinate), water and glycerol were selected as the basal materials, and we want to find the best percentage of plasticizer to improve the mechanical property of compounded plastics. We obtained a plastic sample with better tensile strength of 10.60 ± 0.10 MPa, while the percentage of plasticizer was 9 ％. A plastic sample had better elongation at break of 87 ± 11 ％, while the percentage of plasticizer were 11 ％. A plastic sample had better Modulus of 435.0 ± 22.4 MPa, while the percentage of plasticizer was 10 %. It could conclude in this section that if the percentage of plasticizer is over 10 %, it will increase elongation, but other mechanical property will decrease. In the second part of experiment, in order to improve the tensile strength and elongation of compounded plastics, we designed a 23 factorial experiment, we find that while the percentage of plasticizer was 14 ％, glycerol and water ratio was 4：1, PBS and starch ratio was 7：3, the plastics had best tensile strength of 13.43 ± 0.42 MPa, and elongation of 256 ± 4 ％. The third part of experiment, we design a response surface methodology to chose three process factors glycerol(A), water(B) and corn starch(C) with five levels to study the mathematic models for predicting the mechanical property. We obtained a mathematics model for tensile strength as . Due to the abnormality problem of residues between model and data, we made a log10 transformation of elongation data and obtained a better predicted model for elongation as . We also made a reciprocal square root transformation for the modulus data, and obtained a predicted model as . This study indicate that PBS can replace some of the expensive degradable polyesters in the compounded plastics that blend with starch.