Papers by Keyword: Cellulose Diacetate

Abstract: The value of surface tension is important for choosing oil in CA fibers production. So indirect method were used to analyze the surface tension of CA fibers in this paper. First, Chips of CA were dissolved in acetone solution with 5%, 10%, 15% three kinds of concentration. The three kinds of concentration of the solution were heated 5 hours with 55°C and then standing and defoaming for 24h. Squeeze the solution with two flat glass slides to make the membranes. Second, choose deionized water, Glycerin, Formamide, Bromonaphthalene and Diiodomethane with different polarity as tested liquids to measure the contact angle of CA membrane with JC2000C contact angle meter. Then, Zisman’s linear extrapolation method was used to measure the critical surface tension of CA membranes. On the other hand, S. Wu’S harmonic equation on average method was used too for comparison. The value of two different methods was the same, 42 mN/m, and the result indicated that the estimated method was reliable.

Abstract: Three ionic liquids, 1-butyl-3-methylimidazolium terafluoroborate (BMIMBF₄), 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIMOTF) and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF₆) were applied as the plasticizers of CDA. Among three ILs, BMIMBF₄ was considered to be the most effective plasticizer, which was confirmed by TGA and DMA. The interaction between ILs and CDA was also investigated.

Abstract: A new biodegradable copolymer of cellulose diacetate and poly(p-dioxanone) (PPDO) was prepared through a couple-grafting procedure. PPDO was functionalized with the isocyanate group, and then PPDO terminated with the isocyanate group was enabled to react with the hydroxyl groups of cellulose diacetate. The length of PPDO graft chains can be controlled easily by using the prepolymers of PPDO with different molecular weights. The resulting products were thoroughly characterized with FT-IR, ¹H-NMR. The mechanical properties of the copolymers were affected greatly by the length of PPDO segment.

Abstract: To improve the thermal behavior of cellulose diacetate, cellulose diacetate-graft-poly(lactic acid) copolymers (CDA-g-PLAs) were synthesized by ring-opening polymerization of L-lactide using stannous octoate (Sn(Oct)2) as catalyst. The molecular structure of the copolymer was characterized by FT-IR and 1H-NMR and the thermal properties were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TG-DTA). The results showed that the product was grafted copolymer of cellulose diacetate-graft-poly(lactic acid) with different side-chain structure. The thermal processing properties of CDA-g-PLAs are remarkably improved with melting temperature(Tm) about 140°C which lower than that of CDA and decomposition temperature (Td) higher than 260°C.

Abstract: Melt processable plasticized cellulose diacetate (CDA) was prepared using triacetin (TA) as a plasticizer and its mechanical properties were characterized. The processability of the plasticized CDA was further enhanced by using a small amount of epoxidized soybean oil as a secondary plasticizer. The glass transition temperature of the plasticized CDA was observed at 50°C lower than that of the virgin CDA and the incorporation of 5 % of ESO also resulted in an additional 20°C decrease in the Tg value. In order to obtain practical processing conditions, a plasticizer content of more than 20 wt % should be used.