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行政院國家科學委員會 技術與知識應用型產學合作計畫. 計畫主持人:葉正濤教授. 計畫 名稱: 細菌纖維素纖維 / 生物可分解 高分子合複材備開發. 執行期間:自 100 年 6 月 01 日至 101 年 5 月 31 日. 預期成果. 國際研討會論文發表.
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行政院國家科學委員會技術與知識應用型產學合作計畫行政院國家科學委員會技術與知識應用型產學合作計畫 計畫主持人:葉正濤教授 計畫名稱:細菌纖維素纖維/生物可分解 高分子合複材備開發 執行期間:自100年6月01日至101年5月31日
國際研討會論文發表 • Jen-taut Yeh, Tai-Chin Chiang, Chuen-Kai Wang, Lu-Kai Huang, Chung- Hao Hsu, Chi-huiTsou, Kuo-Huang Hsieh, Chien-Yu Yeh, Su-Chen Chen, Kan-nan Chen and Chi-yuan Huang, “Preparation and Characterization of Bacterial Cellulose Nanofibers” EWLP 2012: 12th European Workshop on Lignocellulosics and Pulp, Espoo, Finland, August 27-30, 2012. • 2. Jen-taut Yeh, Tai-Chin Chiang ,Wen-Jie Yang, Li Cheng, Zhi-Dong Li, Alice Yeh, Chuen-Kai Wang,,Lu-Kai Huang,Chung-Hao Hsu, Kuo-Huang Hsieh, Chien-RongYeh and Su-Chen Chen ”Preparation and Characterization of NovelThermoplastic Starch Nanocomposites Reinforced with Bacterial Cellulose Fibers” EWLP 2012: 12th European Workshop onLignocellulosics and Pulp, Espoo, Finland, August 27-30, 2012.
國際期刊論文發表 • 1. Jen-taut Yeh, Tai-Chin Chiang, Chuen-Kai Wang, Chih-Chen Tsai, Lu-Kai Huang, • Chung-Hao Hsu, Yuan-jin Ho, Su-Chen Chen,Kan-nan Chen and Chi-yuan • Huang, “Preparation and Characterization of Bacterial Cellulose Nanofibers” • Holzforschung - International Journal of the Biology, Chemistry, Physics and • Technology of Wood ” , submitted for publication. • Jen-taut Yeh, Tai-Chin Chiang, Chi-HuiTsou,Wen-Jie Yang , Li Cheng, Zhi-Dong Li, Alice Yeh, Kuo-Huang Hsieh and Su-Chen Chen, “ Preparation and Characterization of NovelThermoplastic Starch Nanocomposites Reinforced with Bacterial Cellulose Fibers”Holzforschung-International Journal of the Biology, Chemistry, Physics and Technology of Wood, submitted for publication. • Jen-taut Yeh, Chuen-Kai Wang, Jhih-Wun Shao, Chih-Chen Tsai, Chung-Hao Hsu, Ming-Zheng Xiao, Chin-San Wuand Su-chen Chen, “Ultradrawing Properties of Novel Ultra-high Molecular Weight Polyethylene Composite Fibers filled with Bacterial Cellulose Nanofibers” , Polym. Int., paper in preparation.
專利申請 • 微波暨機械爆破分散法製備細菌纖維素纖維暨改性細菌纖維素纖維補強的疏水型澱粉基全生物降解複合材料
Abstract Varying culture media prepared from four individual sugar sources were cultivated with Acetobacterxylinum to prepare bacterial cellulose fibers using various cultivation conditions (e.g. sugar contents, temperatures, pH values and air flow rates). Regardless of the sugar sources, sugar contents, temperatures, pH values and air flow rates of the culture media, the ultimate achievable yields of Acetobacterxylinum and bacterial cellulose products cultivated in each 100 ml culture medium are around 5.26×109 CFU and 52 grams, respectively. Regardless of the sugar sources, sugar contents and temperatures of the culture media, the contents and degrees of polymerization of a-celluloses of cultivated bacterial celluloses remained nearly the same at 95% and 6200, respectively. In contrast, the degrees of polymerization of a-celluloses of bacterial celluloses cultivated in the culture media increase significantly as the pH values and/or air flow rates reduce, although the contents of a-celluloses of bacterial celluloses prepared from varying pH values and air flow rates of culture media remained relatively unchanged at 95%.
Experimental • Compositions of Culture Media • (Kinds of Sugars) • 1.Brown Sugar • 2.Sucrose • 3.Glucose • 4.Granular Sugar Cultivated Conditions • Temperatures (℃) • Sugar Contents pH Values • Air Flow rates(ml/sec) Calculation and Analysis • Growth rates of Acetobacterxylinum • Bacterial Cellulose Product Degrees of Polymerization of α-Cellulose Contents of α-cellulose in bacterial celluloses (%)
Table 1 Compositions of culture media and cultivated conditions used for cultivation of Acetobacterxylinum.
Figure 1Yields of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) in 100 ml brown sugar(□, ○); sucrose(□, ○); glucose(□, ○) and granular sugar(□, ○) added culture media at 30oC, pH 7 and 8.5 wt% sugar content.
Figure 2 Growth rates of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) in 100 ml brown sugar (□, ○); sucrose (□, ○); glucose (□, ○) and granular sugar (□, ○) added culture media at 30oC, pH 7 and 8.5 wt% sugar content.
Figure 3 Yields of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) at 30oC and pH 7 in 100 ml granular sugar added culture media with 8.5 wt% (□, ○), 12.7 wt% (□, ○), 17 wt% (□, ○) and 34 wt% (□, ○) sugar contents.
Figure 4 Growth rates of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) at 30oC and pH 7 in 100 ml granular sugar added culture media with 8.5 wt% (□, ○), 12.7 wt% (□, ○), 17 wt% (□, ○) and 34 wt% (□, ○) sugar contents.
Figure 5 Yields of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) at 25℃ (□, ○), 27℃ (□, ○), 30℃ (□, ○), 32℃(□, ○) and 36℃ (□, ○) in 100 ml culture media with 12.7 wt% granular sugar content and a pH value at 7.
Figure 6Growth rates of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) at 25℃(□, ○), 27℃(□, ○), 30℃(□, ○), 32℃(□, ○) and 36℃(□, ○) in 100 ml culture media with 12.7 wt% granular sugar content and a pH value at 7.
Figure 7 Yields of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) at 30℃ in 100 ml culture media with 12.7 wt% granular sugar content and pH values at 2 (□, ○), 3 (□, ○), 4 (□, ○) , 5 (□, ○), and 7 (□, ○).
Figure 8 Growth rates of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) at 30℃ in 100 ml culture media with 12.7 wt% granular sugar content and pH values at 2 (□, ○), 3 (□, ○), 4 (□, ○) , 5 (□, ○) and 7 (□, ○).
Figure 9Yields of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) at30℃andan air flow rate of 1.25 (□, ○), 2.5(□, ○) and 3.75 ml/sec (□, ○) in 100 ml culture mediawith 12.7 wt% granular sugar content and a pH values at 5.
Figure 10 Growth rates of Acetobacterxylinum (square symbols) and bacterial cellulose product (circle symbols) at30℃andan air flow rate of 1.25 (□, ○), 2.5 (□, ○) and 3.75 ml/sec (□, ○) in 100 ml culture mediawith 12.7 wt% sugar content and a pH values at 5.
Table 2 Evaluated contents and degrees of polymerization of a-celluloses in bacterial celluloses cultivated at 30oC, pH 7 and 8.5wt% sugar content in varying sugar sources of culture media.
Table 3 Evaluated contents and degrees of polymerization of a-celluloses in bacterial celluloses cultivated at varying sugar contents, temperatures, pH values and/or air flow rates in culture media prepared from granular sugar source.
Conclusions • BC fibers were successfully metabolized by Acetobacterxylinum using varying sugar sources and cultivated conditions. Scanning electron microscopical analyses reveal that the bacterial cellulose products are featured by their reticulated structures consisting of nanoscaled cellulose fibrils.Granular sugars appear to be the best sugar source that improve the growth rates of Acetobacterxylinum and bacterial cellulose products and reduce the time corresponding to the ultimate yields of Acetobacterxylinum and bacterial cellulose products. Regardless of the sugar sources, sugar contents, temperatures, pH values and air flow rates of the culture media, the ultimate achievable yields of Acetobacterxylinum and bacterial cellulose products cultivated in each 100 ml culture medium are around 5.26 × 109 CFU and 52 grams, respectively. This is most likely due to the limited growth space of culture media that can allow to cultivate Acetobacterxylinum and metabalize BC fibers to these amounts.
The growth rates and the time corresponding to the ultimate yields of Acetobacterxylinum and bacterial cellulose products reached a maximal and minimum value, respectively, as the sugar sources, sugar contents, temperatures, pH values and/or air flow rates in culture media approached their corresponding optimal values, respectively. Furher analyses reveal that the amounts of time corresponding to the ultimate yields of Acetobacterxylinum and bacterial cellulose products reduce by more than 60%, as the optimal sugar source, sugar content, temperature, pH value and air flow rate were used to cultivate Acetobacterxylinum and metabalize bacterial cellulose products. • Regardless of the sugar sources, sugar contents and temperatures of the culture media, the contents and degrees of polymerization of a-celluloses of cultivated bacterial celluloses remained nearly the same at 95% and 6200, respectively. In contrast, the degrees of polymerization of a-celluloses of bacterial celluloses cultivated in the culture media increase significantly as the pH values and/or air flow rates reduce, although the contents of a-celluloses of bacterial celluloses prepared from varying pH values and air flow rates of culture media remained relatively unchanged at 95%.
細菌纖維素補強聚乙烯醇/熱塑性澱粉複材製備細菌纖維素補強聚乙烯醇/熱塑性澱粉複材製備
Abstract Novel thermoplastic starch (TPS) resins were successfully prepared by incorporation of bacterial cellulose (BC) and polyvinyl alcohol (PVA) during their gelatinization processes. In which, BC nanofibers were metabolized by Acetobacterxylinum in granular sugar culture media. By blending 8.33 PHC PVA in TPS, the tensile strength (σf) and elongation at break (εf) values of TPS1PVA1/12 specimen improve over 100% and 40%, respectively, than those of the TPSspecimen. After incorporation of BC fibers during the gelatinization processes of TPSxPVAyBCz resins, their σfand εf values improved to a maximal value, respectively, as their BC contents approach an optimum but very small value. In which, improvement over 40% in σfand εf values of TPS1PVA1/12BC1/5000 specimens was found after addition of only 0.02 part BC per hundred parts of corn starch. As evidenced by wide angle X-ray diffraction and thermal analyses of the corn starch, TPS, TPSxPVAy and TPSxPVAyBCz specimens, the natural crystalline structure of corn starch molecules were dismantled after their gelatinization processes. These results clearly suggest that excellent tensile properties of novel TPS can be prepared by addition of proper amounts of PVA and appropriate but very small amounts of BC nanofibers during their gelatinization processes.
Experimental PLA BC TPS BC Plasti-Corder Mixer TPSxBCy TPSxPVAyBCz Injection Molding Testing and Analysis SEM DSC WAXD MTS
Table 1 Sample codes and compositions of the TPS specimen, BC, PVA and/or BC/PVA reinforced TPS specimens.
(a) (b) (c) (d) 圖9(a)BC,(b)氧化BC,(c)MBC1,(d)MBC2樣品之TEM圖。
(a) (b) (c) (d) 圖10(a)BC,(b)氧化BC,(c)MBC1,(d)MBC2樣品之TEM圖。
(c) (a) (b) (d) (e) (f) Figure 11 SEM micrographs of the fracture surfaces of (a) corn starch, (b) TPS, (c)TPS1BC1/5000, (d) TPS1PVA1/12, (e) TPS1PVA1/12BC1/5000 and (f)TPS1PVA1/12BC1/500specimens.
sf ef Tensile strength (MPa) Elongation at break (%) BC contents (PHC) Figure 12 Tensile strength(□) and Elongation at break(○) values of TPS1BCxspecimens.
ef Elongation at break (%) • Tensile strength (MPa) BC contents (PHC) Figure 13 Tensile strength (□)and elongation at break (○)values of TPS1PVA1/12BCx specimens.
Figure 14DSC thermograms of (a) corn starch, (b) TPS, (c) TPS1BC1/10000, (d)TPS1BC1/5000 and (e) TPS1BC1/500 specimens, which were dried at 200℃ for 1 minute before reheat-scanning at 20℃/min.
Figure 15 DSC thermograms of (a) PVA, (b) TPS1PVA1/12, (c) TPS1PVA1/12BC1/10000, (d) TPS1PVA1/12BC1/500 specimens, which were dried at 200oC for 1 minute before reheat-scanning at 20℃/min.
Figure 16 Wide-angle X-ray diffraction patterns of (a) corn starch, (b) TPS, (c) TPS1BC1/10000, (d) TPS1BC1/5000, (e) TPS1BC1/500 and (f) BC specimens.
Figure 17 Wide-angle X-ray diffraction patterns of (a) corn starch, (b) TPS, (c) TPS1PVA1/12, (d) TPS1PVA1/12BC1/10000, (e) TPS1PVA1/12BC1/5000, (f) TPS1PVA1/12BC1/500 and (g) PVA specimens.
Conclusions • After incorporation of BC fibers in TPS during their gelatinization processes, the tensile properties of TPS1BCx specimens improved significantly with the increase in the BC contents and reached the maximal values as the BC contents approach an optimal value at 0.02 parts per hundred parts of corn starches (PHC). • By blending 8.33 PHC PVA in TPS during its gelatinization process, the σf and εf values of TPS1PVA1/12 specimen reached 20.3 MPa and 14.2%, respectively, which are even better than those of the TPS1BC1/5000 specimen prepared with the optimal BC content. Similar to those of TPS1BCx specimens, the σf and εf values of TPS1PVA1/12BCx specimens increased initially with the increase in the BC contents and then reached the maximal values at 28.8 MPa and 16.7%, respectively, as their BC contents approach the optimal value but very small value at 0.02 PHC.
The morphological, thermal and WAXD analyses suggested that A-type starch crystals were dismantled after gelatinization of granular corn starches and likely crystallized as heat-processible starch crystals during the gelatinization of TPS specimen, although the percentage crystallinities of newly formed starch crystals were relatively low. Incorporation of BC nanofibers further inhibits the formation of heat-processible starch crystals during the preparation of TPS1BCx and TPS1PVA1/12BCx specimens. • As a consequence, the peaks and sizes of the DSC melting enththerms and/or diffraction peaksof heat-processible starch crystals of TPS1BCx specimens reduced significantly as their BC contents increase. On the other hand, most of a-form PVA crystals originally present in PVA specimen was dismantled during the preparation process of TPS1PVA1/12 and TPS1PVA1/12BCx specimen. • In which, TPS molecules may somewhat interacted with dissolved PVA molecules and possibly inhibited the crystallization of PVA crystals during their melt-cooling processes. Presumably, the new diffraction peaks at 2q = 15.3o and 20.5o found on WAXD patterns of TPS1PVA1/12BCx specimens were originated from the crystallization of dissolved PVA molecules during their preparation processes, since dissolved PVA molecules may somewhat interact with TPS molecules and crystallized as other crystal forms.