摘要
为提升竹纤维素纳米晶在醋酸纤维素中的分散均匀性,提高醋酸纤维素复合材料的力学性能,以γ-甲基丙烯酰氧基丙基三甲氧基硅烷(硅烷偶联剂KH-570)改性的竹纤维素纳米晶作为增强相,柠檬酸三丁酯为增塑剂,使用溶液浇铸法制备改性竹纤维素纳米晶/柠檬酸三丁酯/醋酸纤维素复合膜。采用傅里叶变换红外光谱、X射线光电子能谱等方法分析竹纤维素纳米晶的结构,通过扫描电镜、紫外-可见光吸收光谱、力学拉伸试验和热重分析等测试手段表征了复合膜的微观形貌、透光率、力学性能和热稳定性。结果表明:经硅烷偶联剂KH-570改性后,竹纤维素纳米晶在醋酸纤维素基体中的分散性得到明显改善。复合膜的透光率随着改性竹纤维素纳米晶质量分数的增加而下降。当添加的改性竹纤维素纳米晶质量分数为3%时,醋酸纤维素复合膜的综合力学性能最佳,应力和应变分别达到60.76 MPa和5.05%。此外,改性竹纤维素纳米晶/柠檬酸三丁酯/醋酸纤维素复合膜与竹纤维素纳米晶/柠檬酸三丁酯/醋酸纤维素复合膜相比具有更优异的热稳定性。
Bio-based polymers are moving into the mainstream, and biodegradable or renewable feedstock-based polymers may soon compete with fossil-based plastics. Cellulose acetate is an excellent biodegradable plastic that can be an alternative to fossil-based plastics. However, the brittleness and low elongation at break have greatly limited the application of cellulose acetate in some fields. The addition of plasticizers can make cellulose acetate flexible, which comes at the expense of the tensile strength of the composite. For this reason, reinforcing or filling agents are necessary to increase the tensile strength of the cellulose acetate. Bamboo cellulose nanocrystals(CNC) have been attracting attention as an optimal reinforcing material to improve the deficient physical properties of natural polymers because of CNC’s advantages of green, economic, and environmentally friendly nature. Nevertheless, the composite process of bamboo cellulose nanocrystals with bamboo cellulose acetate(BCA) matrix usually suffers from poor dispersion, resulting in a poorly reinforced composite. Bamboo cellulose nanocrystals modified with KH-570 were used as the reinforcing phase to achieve uniform dispersion of bamboo CNC in the cellulose acetate matrix, thus improving the mechanical properties of the composites. In addition, the tributyl citrate(TBC) worked as a plasticizer. Laminated films were prepared by the solution casting method. The structure of bamboo CNC was analyzed using the Fourier transform infrared spectroscopy(FT-IR) and X-ray photoelectron spectroscopy(XPS). The composite films’ microscopic morphology, light transmission, mechanical properties, and thermal stability were characterized by the scanning electron microscopy, UV-vis absorption spectroscopy, mechanical tensile testing, and thermogravimetric analysis, respectively. The results showed that the modification of KH-570 maintained a high dimensional stability of CNC in organic solvents and significantly improved the dispersion of CNC in the cellulose acetate matrix. The light transmission of the composite films decreased with the increase of the mass fraction of modified cellulose nanocrystals(M-CNC). When the mass fraction of modified bamboo CNC reached 3%, the best overall mechanical properties of the cellulose acetate composite films were achieved, with the stress and strain reaching 60.76 MPa and 5.05%, respectively. Besides, at the light wavelength of 800 nm, 3%M-CNC/TBC/BCA films could maintain a high light transmission rate of 79.91%. Moreover, the M-CNC/TBC/BCA composite films had better thermal stability than the CNC/TBC/BCA composite films. This study provides theoretical data support and practical reference for developing and utilizing cellulose crystal/cellulose acetate composite reinforcements.
作者
钱诚
肖堯
杨静
杨海艳
王大伟
史正军
QIAN Cheng;XIAO Yao;YANG Jing;YANG Haiyan;WANG Dawei;SHI Zhengjun(Sympodial Bamboos Technological and Engineering Research Center of National Forestry and Grassland Administration,Southwest Forestry University,Kunming 650224,China;Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China,Southwest Forestry University,Kunming 650224,China)
出处
《林业工程学报》
CSCD
北大核心
2023年第1期104-111,共8页
Journal of Forestry Engineering
基金
国家自然科学基金(31971741,31760195)。
关键词
竹纤维素纳米晶
分散性
醋酸纤维素
复合膜
力学性能
热稳定性
bamboo cellulose nanocrystals
dispersion
cellulose acetate
composite films
mechanical properties
thermal stability
