| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1996: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1995: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Research Abstract |
It was confirmed that cellulose acetate (CA) and acetylated wood wereeffectively plasticized respectively by kneading process with dibasic acid anhydride/monoepoxide to produce oligoester (OE) chains at their free hydroxyl groups. And it was also found that CA was plasticized enough to be kneaded with maleic methyl oleate or dodecenylsuccinic anhydride. In this case, addition of epsilon-caprolactone made the processability of the plasticized materials much higher. These reactions were affected by the degrees of substitution of CA,the kinds of reactive plasticizers, the proportions of plasticizers to CA,and kneading time, etc. On the other hand, in the case of using the former plasticizers, it was known that the unreacted monomers and oligomers produced by plasticizers reaction among themselves existed in the materials. They worked as good external plasticizers for CA,however, some of them bled over sheets. It became clear that the amount and length of OE graft chain was effective in controlling external plasticizers bleeding. Moreover, even in the case of insufficient grafing level, addition of methacrylates as the fixing agent was effective to control bleeding when suitable kinds of plasticizers and processing conditions were used. As the results of biodegradation tests for plasticized samples, it was found that the biodegradation rate of the samples became faster when plasticizers have smaller molecular weight, they are aliphatic compounds, and the proportion of starch was higher. In these tests, polypropylene and high density polyethylene were used as non-biodegradable control samples, and CA with degree of substitution 1.7 was used as the matrix polymer of plasticized samples. It was revealed that all the plasticized samples degraded and their weight losses progressed gradually according to the tendency mentioned above, to disappear within 2 years, though the control samples didn't degrade at all.
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