毛竹材动态热机械特性分析

Analysis on Dynamic Mechanical Properties of Phyllostachys pubescens Material

对不同部位、不同竹龄的毛竹材进行动态热机械特性分析,结果表明:在40～300℃的温度范围内,毛竹材的存储模量随温度升高呈逐渐减小的趋势;损耗模量则先增大后减小,当温度达到玻璃化转变温度时,毛竹材损耗模量达到峰值。在竹壁径向上,毛竹材的存储模量和损耗模量沿着竹壁径向由内而外依次增大。随着竹龄的增大,毛竹材的存储模量和损耗模量也逐渐增大。4.5年生毛竹的玻璃化转变温度从竹黄到竹青,逐渐增大,在210.4～222.8℃范围内;0.5年生、2.5年生和4.5年生毛竹材竹肉部分玻璃化转变温度无明显差异。

The dynamic thermo-mechanical properties of Phyllostachys pubescens material at different ages and from different parts of the stalk were studied.The results showed that the storage modulus of the bamboo material decreased gradually when the temperature ranged from 40 ℃ to 300 ℃.The loss modulus increased firstly and then decreased,which reached the peak value when the temperature rose to the glass transition temperature.Moreover,both the storage modulus and loss modulus increased gradually from the inner part to outer part in the radial direction of stalks,and these indices also increased with the age of the plant.In addition,the glass transition temperature for 4.5 year old bamboo changed from 210.4℃ to 222.8℃,and it increased gradually from inner to outer part of the stalk.However,there was no significant difference in glass transition temperature for the major material sampled from 0.5yr,2.5yr and 4.5yr old bamboo plants.