• Journal of the Korean Wood Science and Technology
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• v.38 no.4
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• pp.333-340
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• 2010

The Korean Dendropanax lacquer, made from a natural resinous sap from Dendropanax orbifera Lev., was used as a golden and transparent varnish for the traditional artifacts (armor uits, helmets, arrowheads, etc.) to make them be brilliant golden color. The cured film of the acquer has excellent protective properties such as weatherability, water resistance, and nticorrosive. But, one of disadvantages is that takes a long time and much energy to fulfill curing the lacquer. The chemical constituents of the lacquer contained conjugated diene compounds s the photopolymerizable monomers. These monomers easily polymerized in sunlight to form olden-colored, hard-coating films in a short time. Photooxidation may be one of the most mportant reactions in the chemistry of the lacquer. Although the Korean Dendropanax Lacquer hould be dried to a thoroughly dry stage to achieve optimal film properties, curing with elevated emperatures may be required for the protracted curing time at atmospheric temperature. So we ntended to accelerate the curing rate of the lacquer by dual curing of thermal and radiation uring. The effect of thermal initiator on the thermal curing reaction was evaluated by monitoring he changes in double bond peak with FT-IR. Then the curing rate of the lacquer blended with hermal initiator and photoinitiator together was measured during dual curing using a RPT with V spot curing machine. Thermal initiator not only accelerated the curing rate but also improved he physical property. And the curing rate of the Korean Dendropanax lacquer was improved by ual curing method of thermal and UV curing. According to these results, the application area of he Korean Dendropanax lacquer could be expanded to surface coatings for electronic devices uch as mobile phones or electronics.

• Korean journal of applied entomology
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• v.5_6
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• pp.39-46
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• 1968

This experiment was conducted to study the effects of nitrogen, phosphorus, potassium, and sugar contents in the loaves of five different host plants on tile larval period, pupal period, pupal period, number of eggs in the ovary, and the tolerance of fall webworm larvae (Hyphantria cunea DRURY) to gamma-BHC. The results obtained in this study were as follows; 1. The contents of nitrogen, phosphorus, potassium, and sugar in tile leaves tested were varied with the species of the host plants and sampling time. 2. The larval and pupal periods were also varied with the host plants and generation of the fall webworm. The shortest larval and pupal periods were found in the mulberry and the longest ones in the apple tree, and their periods were shortened much more in the second generation. Except the relation between the larval period and tile nitrogen content in the first generation, significant correlation could not be found between their periods and nitrogen, phosphorus, potassium and surgar contents. The nitrogen contents among the other chemical factors, however, might be much more influenced on their developing period. 3. The pupal weight and number of eggs in the ovary were also varied with the host plants. sex, and generation. In both generations, the greatest pupal weight and number of eggs per female were found in the mulberry and the least ones in the apple tree. No significant correlation could be found between the pupal weight and number of eggs per female and the chemical factors analyzed. However, only the nitrogen content seemed to be highly related to the pupal weight and number of eggs. 4. The tolerance of the fall webworm larval to gamma-BHC was highly varied with the host plants. The host order o( the larval tolerance level to gamma-BHC was box-elder, popla, platanus, apple tree, and mulberry. There was no significant correlation between the larval tolerance to the BHC and the chemical factors analyzed. However, the larvae fed on the host plant with higher pottassium content were shown a tendency to be higher tolerant.