竹炭粉添加對PVA/Silica混成材料性質之影響

Effects of Bamboo Char Powder on the Properties of PVA/Silica Hybrids

本研究以聚乙烯醇（Polyvinyl alcohol；PVA）與四乙基矽氧烷（Tetraethoxysilane,TEOS）在酸性環境下藉由溶膠-凝膠反應（Sol-Gel reaction）製備PVA／Silica混成材料，並於混成材料製備過程中加入孟宗竹竹炭粉，探討所製備PVA-Silica-竹炭粉混成材料之成膜性、耐水性、機械性及熱性質等。由試驗結果得知，添加竹炭粉後之PVA溶液之成膜性不佳，然將PVA溶液與TEOS混合進行溶膠-凝膠反應，並加入竹炭粉，其PVA-Silica-竹炭粉混成材料呈現良好之成膜性，且所得混成材料具備良好之耐水性，浸水後之重量保留率均在85%以上。PVA之拉伸強度可藉由形成PVA-Silica混成材料而提升，然添加竹炭粉則降低其拉伸強度，且隨竹炭粉添加增加，其拉伸強度及破壞伸長率下降。兩種聚合度PVA比較，高聚合度PVA所製備之PVASilica-竹炭粉混成材料之拉伸強度大於低聚合度者。PVA-Silica-竹炭粉混成材料因TEOS所形成之三次元網狀無機矽氧高分子結構及竹炭粉之添加，可提高其耐熱性，使混成材料不易受熱而降解。 PVA-silica hybrids were prepared from polyvinyl alcohol (PVA) and tetraethoxysilane(TEOS) under acid condition by sol-gel reaction, and the bamboo char powder was added in the synthesis process to form the PVA-silica-char hybrids. The film-forming properties, water resistance, mechanicalproperties and thermal properties of PVA-silica-char hybrids were investigated in this study. The resultsshowed that PVA solution blended with bamboo char powder had bad film-forming property, but thePVA-TEOS-char hybrid solution had well film-forming property, the hybrids of PVA-silica-char filmsshowed good water resistance, their weight retention were over 85% after two days of water soaked.The tensile strength of PVA could be improved by transformed to PVA-silica, but the added of bamboochar powder would decrease their tensile strength, and the more bamboo char powder added, the worsetensile strength would be. Comparison between the PVA with higher and lower degree of polymerization,PVA-TEOS-char hybrid formed with the former had higher tensile strength than made with the latter.According to the TGA analysis, the thermal stability of PVA could be improved as transformed to PVASilica-char hybrids due to the three dimensional network structure of inorganic silicon-oxygen and theadded bamboo char powder.

PVA-silica hybrids were prepared from polyvinyl alcohol (PVA) and tetraethoxysilane(TEOS) under acid condition by sol-gel reaction, and the bamboo char powder was added in the synthesis process to form the PVA-silica-char hybrids. The film-forming properties, water resistance, mechanicalproperties and thermal properties of PVA-silica-char hybrids were investigated in this study. The resultsshowed that PVA solution blended with bamboo char powder had bad film-forming property, but thePVA-TEOS-char hybrid solution had well film-forming property, the hybrids of PVA-silica-char filmsshowed good water resistance, their weight retention were over 85% after two days of water soaked.The tensile strength of PVA could be improved by transformed to PVA-silica, but the added of bamboochar powder would decrease their tensile strength, and the more bamboo char powder added, the worsetensile strength would be. Comparison between the PVA with higher and lower degree of polymerization,PVA-TEOS-char hybrid formed with the former had higher tensile strength than made with the latter.According to the TGA analysis, the thermal stability of PVA could be improved as transformed to PVASilica-char hybrids due to the three dimensional network structure of inorganic silicon-oxygen and theadded bamboo char powder.