抗紫外改性纳米纤维素填料的制备及其性能表征

Preparation and characterization of modified nanocellulose filler with UV resistance

以竹浆板为原料,利用硫酸在超声波辅助作用下制备纳米纤维素(NCC),再以高碘酸钠作为氧化剂,将NCC氧化为双醛纳米纤维素(DNCC),然后用肉桂酰肼进行接枝改性制备,得到肉桂酰肼接枝的纳米纤维素(CMH-NCC).研究了高碘酸钠用量对NCC氧化程度和得率的影响,结果表明当高碘酸钠与NCC的质量比为2∶1时,所得DNCC的氧化程度和得率较高,有利于NCC的接枝改性.同时采用FTIR、XRD、TG和UV对CMH-NCC进行测试,结果表明CMH成功地接枝在NCC上,其结晶度较DNCC大幅提高,热学性能也有明显增强,且接枝改性的纳米纤维素表现出良好的紫外光吸收性能.

In this study, bamboo pulp was firstly converted into nanocrystalline cellulose(NCC) with sulfuric acid under ultrasonic condition. Then NCC was oxidized by sodium periodate to get the dialdehyde nanocrystalline cellulose(DNCC), and followed by graft modification by cinnamyl hydrazide(CMH) to obtain the modified nanocrystalline cellulose(CMH-NCC). The effect of sodium periodate dosage on the degree of oxidation and yield of DNCC was investigated. The results showed that mass ratio of sodium periodate to NCC at 2∶1 attributed to the optimum graft modification of NCC, resulting in high level of oxidized dialdehyde nanocrystalline cellulose and yields. The CMH-NCC was further characterized by FTIR, XRD, TG and UV to verify the efficiency of CMH grafting on NCC. The results showed that the degree of crystallinity and thermodynamic performance of grafted NCC was significantly enhanced in comparison with DNCC. Meanwhile, the grafted NCC showed good UV absorption performance.