Preparation of acetylcellulose/silica composites by sol-gel method and their mechanical properties
Preparation of acetylcellulose/silica composites by sol-gel method and their mechanical properties
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DOI：
10.1007/s10853-005-4413-2
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发表时间：
2005-10
影响因子：
4.5
通讯作者：
K. Tanaka;H. Kozuka
中科院分区：
文献类型：
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作者：
K. Tanaka;H. Kozuka
采用溶胶-凝胶法制备了醋酸纤维素（AC）/SiO2复合材料，试图获得与皮质骨相似的杨氏模量和弯曲强度。使Si（OCH 3）4（TMOS）-AC-H 2 O-HNO 3-四氢呋喃-CH 3 OC 2 H 4 OH溶液凝胶化，其中AC/TMOS摩尔比针对AC单体定义，并且在30-70 ℃下干燥凝胶以获得复合物。由AC/TMOS摩尔比= 0.5和1.0的溶液制备的复合材料由富含AC的基体包围的富含二氧化硅的微米级颗粒组成。AC/TMOS = 2.0的复合材料，另一方面，颗粒与基体之间的界面要不那么明显。所有试样均表现出良好的切削加工性能，用电锯切割成5 mm × 2 mm × 4. 4 mm的矩形试样时，均未出现裂纹或断裂。试样进行了三点弯曲试验，在那里的塑性变形程度和断裂应变增加，杨氏模量和弯曲强度降低，在起始溶液中的AC/TMOS比的增加。当凝胶在较高温度下干燥时，杨氏模量和强度增加。杨氏模量和弯曲强度可以分别在1.8-3.9 GPa和48-100 MPa的范围内变化，通过改变溶液中的AC/TMOS比和干燥温度。
Acetylcellulose (AC)/silica composites were prepared by sol-gel method in an attempt to realize materials with Young's moduli and bending strengths similar to those of cortical bones. Si(OCH3)4(TMOS)-AC-H2O-HNO3-tetrahydrofuran-CH3OC2H4OH solutions were allowed to be gelled, where AC/TMOS mole ratios were defined for AC monomers, and the gels were dried at 30–70∘C to obtain composites. The composites prepared from solutions of mole ratios of AC/TMOS = 0.5 and 1.0 were composed of micrometer-sized particles rich in silica surrounded by the matrix rich in AC. The composites from solutions of AC/TMOS = 2.0, on the other hand, the interface between the particles and the matrix was much less distinct. All the composite samples showed good machinability, which could be cut into 5 mm × 2 mm × 4.4 mm rectangular specimens by an electric saw without cracking or fracture. The specimens were subjected to three-point bending test, where the degree of plastic deformation and the fracture strain increased, and Young's modulus and bending strength decreased with increasing AC/TMOS ratio in the starting solutions. When the gels were dried at higher temperatures, Young's modulus and strength increased. Young's modulus and bending strength could be varied in the range of 1.8–3.9 GPa and 48–100 MPa, respectively, by varying the AC/TMOS ratio in solutions and the drying temperature.