应用聚乙二醇对芦苇茎秆的增韧改性  

Toughening Modification of Reed Stalk by PEG

作　　者：赵雪[1] 陈瑶[1] 高建民[1] Zhao Xue;Chen Yao;Gao Jianmin(Beijing Forestry University,Beijing 100083,P.R.China)

机构地区：[1]北京林业大学,北京100083

出　　处：《东北林业大学学报》2020年第10期76-81,共6页Journal of Northeast Forestry University

摘　　要：采用不同相对分子质量聚乙二醇(PEG)改性剂,经负压浸渍方法进行芦苇(Phragmites australis)茎秆增韧改性试验。应用扫描电镜(SEM)观察芦苇茎秆增韧改性前后微观形貌变化;应用万能力学试验机(WAW)及动态热机械性能分析(DMA)测定增韧改性后芦苇茎秆的弯曲性能,并利用三点弯曲法计算弯曲弹性模量、应力-应变关系;应用傅里叶变换红外光谱(FTIR)观察改性芦苇茎秆表面主要官能团的变化;采用干燥器法测定改性芦苇茎秆的吸湿性能。依据试验结果分析不同相对分子质量PEG改性剂对芦苇茎秆力学性能的影响。结果表明:经过PEG改性后,试样的弯曲弹性模量均有不同程度的降低,表明PEG改性较好地提高了芦苇茎秆的韧性。改性芦苇茎秆的韧性,随PEG相对分子质量的提高而增强,其中,PEG6000改性试样的弯曲弹性模量达到181.941 MPa,韧性较未改性试样提高了73%。PEG改性剂可浸入细胞壁或附着在芦苇细胞内部,影响其微观结构以及力学性能。通过动态力学测试可知,改性后的芦苇茎秆在60℃以下时,随温度的升高柔韧性逐渐增大。经吸湿稳定性分析,在相对湿度33%的环境中,改性芦苇茎秆的吸湿稳定性提高,吸湿稳定性随PEG相对分子质量的增加而提高;在相对湿度95%的条件下,PEG6000试样的吸湿稳定性较好。In order to solve the problem that the reed(Phragmites australis)material is prone to brittleness during the weaving process,the applicability of the reed stalk in the reed knitting process is improved.Polyethylene glycol(PEG)modifiers with different molecular weights were used to toughen modified reed stalks by impregnation under negative pressure.The change of microstructure of reed before and after toughening was observed by scanning electron microscope(SEM).The flexural properties of the reed after toughening were measured by a universal testing machine(WAW)and dynamic thermomechanical properties(DMA).The three-point bending method was used to calculate the bending elastic modulus and stress-strain relationship.The main functional groups on the surface of modified reed were observed by Fourier transform infrared spectroscopy(FTIR).The desiccant method was used to determine the hygroscopic properties of modified reed stalks.The results showed that the flexural modulus of the samples after PEG modification decreased to varying degrees,indicating that PEG modification improved the toughness of reeds.The toughness of the modified reed stem increased with the increase in the molecular weight of PEG.The bending elastic modulus of PEG6000 reached 181.941 MPa,which was 73%higher than that of the unmodified sample.According to FT-IR,PEG 6000 is more likely to enter into the stem of reed and react with its internal chemical components,making it easier for the modifier to adhere to the inside of reed cells,thus affecting its microstructure and mechanical properties.It was known from the dynamic mechanical analysis that the flexibility of the modified reed stalk increased gradually with increasing temperature below 60℃.According to the research on the hygroscopic stability,the hygroscopic stability of the modified reed stalk was improved under the environment of relative humidity of 33%.The samples treated with PEG6000 showed better moisture absorption stability under 95%relative humidity.

关 键 词：芦苇茎秆 弯曲性能 增韧改性 聚乙二醇 

分 类 号：S781.2[农业科学—木材科学与技术]