• Polymer(Korea)
• /
• v.30 no.6
• /
• pp.532-537
• /
• 2006

In order to successfully meet the environmental and recycling problems, natural polymer and their derivatives are recognized as a promising biodegradable material. In this study, the biodegradable composites of cellulose diacetate and starch were prepared, and their physical and thermal properties were investigated. For the melting processing, triacetine was added as a plasticizer into the composites. The processability of cellulose diacetate was further enhanced by increasing the amount of starch in the composites. The tensile stress and Young's modulus were decreased and elongation was increased with increasing the amount of starch in them. A $T_g$ value was decreased with increasing the amount of starch in the composites. Also, the morphology of the composites were observed with the SEM.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.8
• /
• pp.1851-1854
• /
• 2009

• Polymer(Korea)
• /
• v.32 no.2
• /
• pp.178-182
• /
• 2008

Cellulose diacetate (CDA) and calcium carbonate ($CaCO_3$) biodegradable composites were prepared by melt mixing in a twin screw extruder and their physical properties were examined. In the melt processing, triacetine and epoxidized soybean oil were added to the composites as a plasticizer and lubricant, respectively. The optimal conditions for the preparation of the biodegradable composites were determined. Acetic acids ($CH_3COOH$) were made by pyrolysis acetyl group ($-OC (O)CH_3$) of CDA and TA in melt processing. Increasing the amount of $CaCO_3$ in the composites resulted in further enhancement of the $CH_3COOH$ absorption effects. The tensile strength and elongation were decreased, and Young's modulus and $T_g$ value increased with increasing amount of $CaCO_3$.

• Polymer(Korea)
• /
• v.30 no.1
• /
• pp.70-74
• /
• 2006

Plasticized cellulose diacetate(CDA) was prepared by homogenizing cellulose diacetate(CDA), triacetin(TA) and epoxidized soybean oil (ESO) in a high-speed mixer, then the CDA mixture was mixed with ramie fiber to produce a green composite material. In DMA analysis, the glass transition temperature of plasticized CDA and the composite was observed at $85\;^{\circ}C\;and\;140\;^{\circ}C$, respectively. A composite reinforced with alkali treated ramie fiber exhibited significantly higher mechanical properties, such as $15\;^{\circ}C$ increase in tensile strength as well as $41\;^{\circ}C$ increase in Young's modulus when compared with commercial polypropylene. In the SEM image analysis, much enhanced adhesion between plasticized CDA and alkali treated ramie fiber (AIRa) was observed.

• Polymer(Korea)
• /
• v.33 no.3
• /
• pp.243-247
• /
• 2009

Cellulose diacetate (CDA) was plasticized with triacetine (TA) and epoxidized soybean oil (ESO) in a high speed mixer. Composites of plasticized CDA and zeolite were prepared by a melting process. The $T_g$ value, $106^{\circ}C$ of the plasticized CDA was confirmed by DMA analysis. The $T_g$ value of the CDA with 50% zeolite was $125^{\circ}C$. As the content of zeolite was increased from 10 to 50% the modulus of the composite was increased from 1.7to 3.6 GPa by two times over the plasticized CDA, and its tensile strength was increased to 62 MPa and then decreased down 51 MPa, and its elongation was increased to 10% and then decreased down 3.2%. In the SEM image, the compatibility between CDA and zeolite was observed. Increasing the amount of zeolite in the composites resulted in further enhancement of the $CH_3COOH$ absorption effects.

• Polymer(Korea)
• /
• v.30 no.3
• /
• pp.202-206
• /
• 2006

The plasticized cellulose diacetate (CDA) was prepared by melt processing methods using triacetine (TA) as a plasticizer. Additionally, processability of CDA was enhanced by using epoxidized soybean oil as a secondary plasticizer. The glass transition temperature of plasticized CDA was observed at $50^{\circ}C$ lower than virgin CDA and the incorporation of 5% ESO also resulted in the additional $20^{\circ}C$ decrease in the $T_g$. The tensile properties and modulus of plasticized CDA were better than commercial PP and PLA. The aerobic biodegradability of CDA in controlled compositing condition resulted in 90% of degradation during 60 days.

• Polymer(Korea)
• /
• v.28 no.6
• /
• pp.551-555
• /
• 2004

Cellulose diacetate (CDA) nanocomposite films were prepared by using various plasticizer and montmorillonite nanofiller in methylene chloride/ethanol (9:1 w/w) mixed solution. The thermal property (T$_{g}$) of prepared CDA films was observed by DSC and T$_{g}$ of the films was decreased with the increase in the plasticizer content. The degree of dispersion of MMT in the CDA film was observed by XRD and mechanical property of CDA film was measured by tensile strength and Young's modulus. When the plasticizer was added into the CDA film upto 30 wt%, the Young's modulus of film was decreased from 1930 MPa to 1131 MPa but was increased from 1731 MPa to 2272 MPa when the MMT was added into the film upto 7 wt%. The mechanical properties of CDA films were decreased by addition of plasticizer but strengthened by the incorporation of MMT.

• Journal of the Korean Applied Science and Technology
• /
• v.26 no.4
• /
• pp.428-433
• /
• 2009

Cellulose triacetate (CTA) was prepared from cotton linter and pulps which contain various contents of $\alpha$-cellulose. CTA which contains 2.8 of degree of substitution (DS) and 222 of degree of polymerization (DP) was obtained from V-81 pulp under the heterogeneous system. The DS was measured by the titration method, and the DP was obtained by measurement of viscosity. FT-IR spectometer (FT-IR 6300, JASCO) was used to analyze the chemical structure of raw materials and cellulose triacetate, and X-ray diffractometer (X-pert MPD PW3040, Philips) was used to confirm the crystal structure and to calculate the relative crystallinity index (RCI). As $\alpha$-cellulose content in pulp increased, the acetylation yield increased. Besides with a kind of pulp, it contains insoluble residue which was mainly formed due to the formation of glucomannan triacetate and xylan diacetate during the esterification.

• Fibers and Polymers
• /
• v.6 no.3
• /
• pp.244-249
• /
• 2005

enVix is a novel regenerated cellulosic fiber, which is prepared from cellulose diacetate fiber using environmentally friendly manufacturing process. Vat dyeing properties of the enVix were investigated and compared with those ofregular viscose rayon. The enVix exhibited better dyeability than viscose rayon. The colour yields of vat dyes on the enVix were found to be dependent on dyeing temperature as well as the amount of levelling agent and salt. Good build-up and good to excellent fastness properties were obtained on the en Vix fabric.

• Journal of Photoscience
• /
• v.1 no.2
• /
• pp.135-141
• /
• 1994

Elevated near-UV radiation, containing a large amount of UV-B and a small amount of UV-C, inhibited the development of leaves and tillers, the increase in biomass production, the elongation of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Elevated UV-B radiation filtered through cellulose diacetate film or UV-31 cut filter (transmission down to 290 nm) similarly suppressed each growth component above. Near-UV radiation-caused injuries were alleviated either by elevated CO$_2$ atmosphere or by exposure to high irradiance-visible radiation. On the basis of these findings, we examined cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes ( aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups. It was shown that .various cultivars having different sensitivities to the effects of near-UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to near-UV radiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of near-UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultivars are cultivated. From the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F$_2$ plants generated by reciprocally crossing Sasanishiki and Norin 1 and F$_3$ lines generated by self-fertilizing F$_2$ plants, it was evident that the resistance to the inhibitory effects of elevated near-UV radiation in these rice plants was controlled by recessive polygenes.