本文選題：纖維素納米晶 + 彩色膜��； 參考：《青島科技大學(xué)》2017年碩士論文

【摘要】：本文針對(duì)纖維素納米晶彩色膜韌性差的缺點(diǎn),采用多種策略對(duì)纖維素納米晶彩色膜進(jìn)行增韌改性,以期獲得具有實(shí)用價(jià)值的纖維納米晶彩色膜。借助紫外可見光譜(UV-Vis)、掃描電鏡(SEM)、原子力顯微鏡(AFM)、紅外(FTIR)、X射線衍射(XRD)、熱失重(TGA)、DMA等表征手段對(duì)獲得的納米晶及其增韌后的彩色膜進(jìn)行表征分析。我們首先采用硫酸酸解法制備了纖維素I晶型的纖維素納米晶,并結(jié)合真空抽濾技術(shù)獲得均一顏色的纖維素納米晶彩色膜。并且發(fā)現(xiàn)采用真空抽濾技術(shù)制備彩色膜時(shí)超聲時(shí)間對(duì)彩色膜顏色產(chǎn)生明顯影響,隨著超聲時(shí)間延長(zhǎng)彩色膜顏色紅移,從而可以通過控制超聲時(shí)間獲得所需顏色彩色膜。對(duì)獲得的彩色膜進(jìn)行堿處理,之后發(fā)現(xiàn)經(jīng)過堿處理后纖維素納米晶膜螺旋形液晶結(jié)構(gòu)仍能保留,膜仍保持顏色,并且由于纖維素晶型轉(zhuǎn)化及無定形區(qū)含量提高,彩色膜顏色發(fā)生明顯變化,由于堿處理使纖維素納米晶發(fā)生聚集態(tài)結(jié)構(gòu)改變,從而導(dǎo)致彩色膜的韌性得到大幅提高。堿處理也會(huì)使納米晶表面的磺酸根脫除從而使彩色膜的耐熱性得到大幅提升。我們還嘗試采用真空抽濾法制備纖維納米晶(CNC)/聚乙烯醇(PVA)的復(fù)合彩色膜,經(jīng)實(shí)驗(yàn)發(fā)現(xiàn)采用真空抽濾技術(shù)可以制備出CNC/PVA復(fù)合彩色膜,同時(shí)將PVA含量提高后,復(fù)合彩色膜顏色并沒有像澆鑄成膜方式制備彩色膜,顏色發(fā)生紅移,而是發(fā)生藍(lán)移。將獲得的復(fù)合彩色膜進(jìn)行堿處理后發(fā)現(xiàn)處理后彩色膜螺旋液晶結(jié)構(gòu)仍能保留且與純CNC彩色膜相似復(fù)合彩色膜的機(jī)械性能及耐熱性得到提升。基于橡膠材料的高彈性,嘗試將丁腈膠乳(NBR)加入纖維素納米晶(CNC)中采用澆鑄成膜(Cast)制備復(fù)合彩色膜,相比高分子聚合物,球形膠乳粒子加入使得復(fù)合彩色膜形成分相結(jié)構(gòu),形成CNC富集相及NBR富集相。對(duì)聚合物而言當(dāng)CNC與聚合物比例為1:0.6便會(huì)失去螺旋液晶結(jié)構(gòu),而膠乳粒子含量在CNC中比例為1:0.9時(shí)仍能保持彩色。同時(shí)NBR膠乳加入能夠提高彩色膜的機(jī)械性能,NBR膠乳包裹住CNC能夠改善CNC彩色膜的熱穩(wěn)定性。
[Abstract]:Aiming at the disadvantage of poor toughness of cellulose nanocrystalline color film, various strategies were adopted to toughen and modify cellulose nanocrystalline color film in order to obtain the practical value of fiber nanocrystalline color film. The obtained nanocrystalline and its toughened color films were characterized by UV-VisT, scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA) with UV visible spectrum, scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Firstly, cellulose I nanocrystals were prepared by sulfuric acid hydrolysis, and uniform color cellulose nanocrystalline color films were obtained by vacuum filtration. It is also found that ultrasonic time has an obvious effect on the color of color film when it is prepared by vacuum filtration technology. The color of color film can be obtained by controlling ultrasonic time by increasing the color shift of color film with ultrasonic time. After alkali treatment, it was found that the helical liquid crystal structure of cellulose nanocrystalline film could still be retained, and the color of the film was still maintained, and the content of amorphous region was increased due to the conversion of cellulose crystal form and the increase of the content of amorphous region in cellulose nanocrystalline film. The color of color film changed obviously, and the structure of cellulose nanocrystalline was changed due to alkali treatment, which resulted in a great improvement of the toughness of color film. Alkali treatment can also remove sulfonic acid from nanocrystalline surface and greatly improve the heat resistance of color film. We also try to fabricate the composite color film of fiber nanocrystalline CNC/PVA / PVA by vacuum filtration. It is found that the CNC/PVA composite color film can be prepared by vacuum filtration, and the content of PVA is increased. The color of composite color film is not red shift, but blue shift. After alkali treatment, it was found that the helical liquid crystal structure of the color film could still be preserved and the mechanical properties and heat resistance of the composite color film were improved as compared with the pure CNC color film. Based on the high elasticity of rubber materials, the composite color film was prepared by adding nitrile latex (NBR) into cellulose nanocrystalline (CNC). Compared with polymer, spherical latex particles formed the phase separation structure of the composite color film. CNC enrichment phase and NBR enrichment phase were formed. For polymer, when the ratio of CNC to polymer is 1: 0.6, the structure of spiral liquid crystal will be lost, while the content of latex particles in CNC of 1: 0.9 can still maintain color. At the same time, the addition of NBR latex can improve the mechanical properties of color film. NBR latex encapsulated CNC can improve the thermal stability of CNC color film.
【學(xué)位授予單位】：青島科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TQ352.7;TB383.2

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