• Elastomers and Composites
• /
• v.46 no.2
• /
• pp.125-131
• /
• 2011

The effects of chopped kenaf fiber concentration on mechanical property of polypropylene (PP) composite are investigated. The addition of kenaf increased the tensile strength, flexural modulus, impact strength, specific gravity, and HDT, while decreased the elongation%, flexural strength, and melt flow index. The increase of mechanical properties is due to increased surface area contacting between fiber and polymer matrix and fiber-fiber interaction. Volatile extractives in the kenaf seemed to decrease the interfacial adhesion between kenaf surface and PP.

• Polymer(Korea)
• /
• v.37 no.5
• /
• pp.613-617
• /
• 2013

The effects of nano size kenaf cellulose fiber on mechanical property of polypropylene (PP) composite were investigated. The addition of nano-kenaf in place of natural kenaf showed higher tensile strength, flexural strength, impact strength, and heat deflection temperature compared to the natural kenaf filled PP composite, while it shows lower melt flow index, elongation%, and flexural modulus. These seemed to be due to the increased surface area of nano-kenaf fiber contacting PP matrix and reduced impurities such as volatile extractives on the fiber surface.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.6
• /
• pp.747-757
• /
• 2014

Since the air contamination by air pollutants from indoor construction materials and daily supplies has been increased in recent decades, the public interest of using environmentally friendly products and improving indoor air quality also attracted much attention. As known as effects of phytoncide, it has been used in construction materials and daily supplies with various method. In this study, hinoki cypress (Chamaecyparis obtusa) was used because of its high contents of phytoncide. The leaves of hinoki cypress (C. obtusa), which generated by pruning, were extracted by steam distillation, and then used as humidification water source. Volatile organic compound (VOC) from C. obtusa were characterized by GC-MS (Gas chromatograph-Mass spectrophotometry) in order to evaluate effects and risks of using C. obtusa extracts. Total 86 types and 116 types of VOC were detected from distilled water (DI water) and C. obtusa extracts, respectively. Aromatic compounds (DI water: 13 types, 53%; C. obtusa extracts: 13 types, 38%) and terpenoids (DI water: 16 types, 23%; C. obtusa extracts: 23 types, 33%) were detected more diverse types and higher amount than other compound categories. No additional aromatic compounds were found from C. obtusa extracts, so C. obtusa extracts did not affect on aromatic compounds emission. However, in terpenoids, total amount of emission from C. obtusa extracts increased to 33% from 23% (DI water) and 7 more types of compounds were found from C. obtusa extracts. Especially, from C. obtusa extracts, terpinen-4-ol was emitted 71 times higher than DI water. During the humidification with C. obtusa extracts, emitted terpenoid compounds were well known for higher anti-bacterial, anti-insect, and anti-septic functions, but also these had anti-hypertensive and anti-cancer activities. Therefore, terpenoids from C. obtusa extracts can help to improve public health by using humidifier.

• Journal of the Korean Society of Tobacco Science
• /
• v.14 no.2
• /
• pp.159-167
• /
• 1992

It would be clear that the constituents of the leaf surface lipid is ye비 important as an evaluation index of tobacco leaf quality since the quality of tobacco specific aroma with leaf species depends on the contents of the lipid and the strength of the aroma is determined by the amounts of the lipid secreted. For the reason, a rapid and peproducible method to quantify DVT, which is a kind of lipid, has been studied. The biosynthesis procedure of DVT in leaf growing processes, and the volatile or decompositional characters of DVT in leaf drying processes were also discussed. In consequence, it might be possible to get the data available to the cultivation of better tobacco leaf and the manufacture of cigarettes with better aroma and taste. The results obtained from this study are as follows. 1. Chloroform/dichloromethane solvent was better than chloroform alone for DVT extraction. The extraction yields of the leaf surface lipid were about 5% 2. The extractives with dichloromethane were treated by silylation with BSTPa and the quantitative analysis of DVT was carried out using SE -54 fused silica capillary column. It was found that rapid and reproducible data could be obtained from these methods. 3. In flue - cured tobacco species, DVT contents were $30.3\mu\textrm{g}/cm^2$ in the beginning stage of leaf drying processes and $12.1\mu\textrm{g}/cm^2$ corresponded to 30% levels of the beginning stage, in the end stage. 4. DVT contents in Burley mere 2 times as large as those in fluecured tobacco. DVT in the upper stalk position of leaf was 3 times larger than that in the lower stalk position. 5. DVT of tobacco leaves was decomposed by $SO_2$ gas or the sun light. The decomposition rate was largest in the sample used methanol as a extraction solvent.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.2
• /
• pp.274-279
• /
• 1995

Seasonal variation of the taste components such as free amino acids, nucleotides, quarternary ammonium bases, and guanidino compounds in warty sea squirt(S. clava) were determined bimonthly from April to October for its food quality contributed in Korean seafood dishes. Fifty to sixty two percentage of the extractable nitrogen was free amino acids, and mainely it composed of taurine, proline, glutamic acid, glycine and glycinebetaine. Among the various taste component, betaine's level was somewhat higher(11~15%) and nucleotides related compounds also followed(5~8%). Most of nitrogenous compounds in the extractives reached to a maximum value in June and AMP content was relatively higher than the other nucleotides. The major organic acids were composed of succinic acid, malic acid, lactic acid and pyroglutaric acid in S. clava. The result of omission test suggested that the taste of S. clava is mainly attributed to free amino acids, betaines, nucleotides and non-volatile organic acid in order.