3.2. Effect of temperature on composites
Fig. 13 displays the mean weekly variation of temperature
in the composite material. It can be observed
that it does not exceed 50 C. Normally, the temperature
will affect the property of natural fiber based construction
material when a temperature of about 75 C or
above is reached. Durian fiber based lightweight construction
material was composed of fibers from durian
peel. Cellulose content in the durian peel is quite high, as
shown in Table 1. The decomposition of cellulose in an
alkaline environment can take place in accordance with
different mechanisms (Shafiq et al., 1988). One is the
peeling-off mechanism which occurs at the end of the
molecular chain. Since the degree of polymerization of
cellulose of many natural fibers is high, about 25,000,
the peeling-off mechanism is fairly harmless in itself.
Peeling-off is said to occur within a wide temperature
interval but the rate does not become markedly high
until a temperature of about 75 C or above is reached.
The other form of cellulose decomposition consists of
alkaline hydrolysis. This is caused by the molecular
chain to divide and the degree of polymerization is decreased.
Since the division of the molecular chain entails
the exposure of new end groups, the peeling-off mechanism
can be started. Alkaline hydrolysis does not take
place at a high rate until the temperature is in excess of
100 C is present. Thus the primary causes of the change
3.2. Effect of temperature on compositesFig. 13 displays the mean weekly variation of temperaturein the composite material. It can be observedthat it does not exceed 50 C. Normally, the temperaturewill affect the property of natural fiber based constructionmaterial when a temperature of about 75 C orabove is reached. Durian fiber based lightweight constructionmaterial was composed of fibers from durianpeel. Cellulose content in the durian peel is quite high, asshown in Table 1. The decomposition of cellulose in analkaline environment can take place in accordance withdifferent mechanisms (Shafiq et al., 1988). One is thepeeling-off mechanism which occurs at the end of themolecular chain. Since the degree of polymerization ofcellulose of many natural fibers is high, about 25,000,the peeling-off mechanism is fairly harmless in itself.Peeling-off is said to occur within a wide temperatureinterval but the rate does not become markedly highuntil a temperature of about 75 C or above is reached.The other form of cellulose decomposition consists ofalkaline hydrolysis. This is caused by the molecularchain to divide and the degree of polymerization is decreased.Since the division of the molecular chain entailsthe exposure of new end groups, the peeling-off mechanismcan be started. Alkaline hydrolysis does not takeplace at a high rate until the temperature is in excess of100 C is present. Thus the primary causes of the change
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