碳纤维增强桉杨复合胶合板的制备及性能研究

PREPARATION AND PROPERTIES OF CARBON FIBER REINFORCED EUCALYPTUS-POPLAR COMPOSITE PLYWOOD

为开发碳纤维/木基复合材,设计了全桉木、全杨木、杨桉交错、桉杨交错四种结构用桉杨复合胶合板,采用碳纤维(CF)进行表面增强,研究增强前后桉杨复合胶合板的物理力学性能以及保温性能,探讨老化前后四种结构之间的性能变化。结果表明:经碳纤维表面增强后,桉杨交错结构吸水厚度膨胀率为2.6%,下降幅度为44.7%,吸水率下降幅度为46.5%;四种结构浸渍剥离性能均满足标准,最好为桉杨交错结构;桉杨交错结构老化前纵向静曲强度为98.5 MPa,提高率为107.4%,纵向弹性模量为15810 MPa,提高率为129.8%,老化后杨桉交错结构纵向弹性模量为10150 MPa,提高率为176.3%,且杨桉交错结构胶合强度可达1.74 MPa,但对于横向静曲强度、弹性模量和胶合强度提高均较小。综合而言,碳纤维增强后物理力学性能较好的结构为杨桉交错和桉杨交错,总体反映了桉杨复合胶合板结构上纵横强度比差异较大,在实际应用中根据需求调整纵横强度设计比例;经碳纤维表面增强后桉杨复合胶合板导热系数均值为0.44 W/(m·℃),导热系数值接近保温材料,碳纤维表面增强后对其保温性能影响不明显。

In order to develop carbon fiber reinforced wood-based composites, four kinds of structure with eucalyptus-poplar composite panel were designed with eucalyptus/eucalyptus,poplar/poplar,crossed poplar/eucalyptus and eucalyptus/poplar,and the carbon fiber（ CF） was covered on the surface of composite panel to enhance its properties. The physical mechanical properties and thermal insulation properties of CF reinforced eucalyptus-poplar composite panel were analyzed and the performance changes were discussed before and after aging. After the carbon fiber surface enhancement,the physical and mechanical properties of the four kinds of eucalyptus-poplar composite panel have been greatly improved. Among them,the expansion rate of water absorption of eucalyptus/poplar was 2. 6%,for which the decrease rate was 44. 7%,and the water absorption rate decreased by 46. 5%. The delamination properties of the four structures all meet the standard,and the best was poplar/eucalyptus. The longitudinal modulus of rupture of eucalyptus/poplar was 98. 5 MPa before aging,and the improvement rate was 107. 4%. The longitudinal modulus of elasticity of eucalyptus/poplar was 15810 MPa before aging,for which the improvement rate was 129. 8%. The longitudinal modulus of elasticity of the aged poplar/eucalyptus was 10150 MPa,for which the increased rate was 176. 3%,and the bonding strength of poplar/eucalyptus was up to 1. 74 MPa. Whereas,the transverse modulus of rupture,modulus of elasticity and bonding strength of the composites were smaller than those of the control group. Overall,the structure of poplar/eucalyptus and eucalyptus/poplar by the carbon fiber enhanced surface had better physical and mechanical properties,and the ratio of longitudinal and transverse strength of the eucalyptus-poplar composite panel was quite different. In the practical application,the aspect ratio of longitudinal and transverse strength need to be adjusted according to the demand. After the surface enhancement of the carbon fiber,the average thermal conductivity of eucalyptus-poplar composite panel was 0. 44 W/（ m·℃）. As indicated,and the thermal conductivity was close to the insulation,and the effect of carbon fiber on the thermal insulation properties of eucalyptus-poplar composite panel was not significant.