摘要
利用动态机械热分析仪（DMTA）研究毛竹Phyllostachys edulis材在不同初含水率、径向部位、竹龄和高度等条件下的玻璃化转变温度（Tg）并分析其变化规律,旨在为竹材的软化和展平提供理论依据。结果表明：1在温度50.0-250.0℃范围,随初含水率增加（0%,15%,30%,60%和饱水）,毛竹材的玻璃化转变温度显著降低,从绝干材的217.3℃降低到饱水材的113.0℃,毛竹材在较低含水率（〈15%）范围内比高含水率（〉15%）范围内变化对毛竹材的玻璃化转变温度影响更明显,表明提高毛竹材初含水率对竹材软化有益。2在相同竹龄、初含水率和高度条件下的毛竹材沿竹壁径向的竹青、竹肉和竹黄的玻璃化转变温度有差别但不显著,两两之间最大和最小分别相差12.0℃和0.5℃。3在相同径向部位和含水率条件下,不同竹龄和不同高度的毛竹材玻璃化转变温度均无明显差异,相差在5.0℃以内。这有助于实际生产中最大化利用原材料。
To provide a theoretical basis for bamboo softening and flattening, a dynamic mechanical analyzer（DMTA） was used at various initial moisture contents（MC）（0%, 15%, 30%, 60%, and water saturation）,radial positions（outer, median, and inner layers）, ages（3, 5, and 7 years old）, and heights（2.5 m, 4.0 m, 5.5m） to study the glass transition temperature（Tg） of Phyllostachys edulis bamboo. The test were performed between 30.0-260.0 ℃ with heating rate 5 ℃·min^-1, and amplitude 5 μm and a frequency of 3 Hz. Results showed： that（1） with an increase of MC at 50.0-250.0 ℃, Tgdecreased from 217.3 ℃ to 113.0 ℃. Initial MC changes at lower levels（〈15% MC） had a greater effect on Tgthan moisture content changes 〉15% MC.（2）The Tgfor the outer, median, and inner layers of bamboo along the radial direction showed little differences under the same age, initial MC, and height; maximum difference in Tgwas 12.0 ℃ and minimum was 0.5 ℃.（3）With identical radial positions and initial MC, different ages and the heights did not affect bamboo Tgwhich had differences of less than 5.0 ℃. This study showed that an increased initial MC was good for bamboo softening and will, thus, help make full use of materials in the production process.
出处
《浙江农林大学学报》
CAS
CSCD
北大核心
2015年第6期897-902,共6页
Journal of Zhejiang A&F University
基金
国际竹藤中心专项资助项目(1632013002)
浙江省重大科技专项资助项目(2014C02018
2014C02004)
关键词
木材科学与技术
毛竹
竹材
动态机械热分析仪
玻璃化转变温度
储能模量
损耗模量
wood science and technology
Phyllostachys edulis
bamboo timber
dynamic thermal mechanical analysis
glass transition temperature
storage modulus
loss modulus
作者简介
黄梦雪，从事竹木材加工与利用研究。E—mail：464685741@qq．com。
通信作者：张文标，教授，博士，从事竹木材加工与利用研究。E-mail：zwb@zafu．edu．cn
