环保材料用CNF/CAS复合膜的制备及其性能表征

Preparation and Characterization of CNF/CAS Composite Membranes for Environmental Protection Materials

探讨从咖啡壳内提取纳米纤维素(CNF)的方法,并对CNF微观形貌进行了表征,之后制备得到咖啡壳CNF增强丙烯酸树脂复合材料并测试了其热膨胀系数与透光性能。结果表明,咖啡壳纯化纤维素含量是82. 6%;通过超细研磨仪进行高强度剪切处理后,可以有效实现CNF的分离过程,形成均匀分散状态的CNF直径介于15~30 nm范围内,获得了很高的CNF长径比,并且相互之间还会交织形成三维网状结构。CNF纯膜厚度等于22μm,通过和丙烯酸的复合,膜厚将达到90μm。在波长为600 nm处对纯CNF膜进行测试得到其透光率等于18. 2%,同样在600 nm处对复合膜进行透光率测试为84. 9%。当温度介于25~160℃之间时,纯CNF膜具有很低的热膨胀系数,将其添加到丙烯酸中形成复合材料能够显著减小整体的热膨胀系数。

In this paper,the method of extracting nano-crystalline cellulose( CNF) from coffee shell was discussed,and the microstructure of CNF was characterized. Then the coffee shell CNF reinforced acrylic composite was prepared and its thermal expansion coefficient and light transmission property were tested. The results show that the purified cellulose content of coffee shell is 82. 6%. The separation process of CNF could be effectively realized by high-strength shear treatment with the ultra-fine grinding instrument. The diameter of the CNF in a uniform and dispersed state could be 15 ~ 30 nm,and a high length-diameter ratio of CNF is obtained. In addition,the CNF interweaves with each other has formed a three-dimensional network structure.CNF pure film thickness is equal to 22 μm,and compounding with acrylic acid composite film,the thickness could reach 90 μm. The light transmittance of pure CNF film at 600 nm could achieve 18. 2%,and the composite film at 600 nm is 84. 9%. When the temperature range is 25 ~ 160 ℃,the pure CNF membrane has very low thermal expansion coefficient. The addition of CNF to the acrylic acid formed the composite materials could significantly reduce the thermal expansion coefficient of the whole material.