Multistage Sonication Effect on the Composition and Properties of Degraded Chitosan Product
<span style="font-size: 11pt; line-height: 150%; letter-spacing: -0.15pt;"><font face="arial">The sonication method randomly breaks polymer chains to produce a varied distribution of products. A scheme with multistage sonication steps is proposed to identify oligome...
Main Authors: | , , , , |
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Format: | Article |
Language: | English |
Published: |
Universitas Indonesia
2019-04-01
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Series: | Makara Journal of Technology |
Subjects: | |
Online Access: | http://journal.ui.ac.id/technology/journal/article/view/3585 |
Summary: | <span style="font-size: 11pt; line-height: 150%; letter-spacing: -0.15pt;"><font face="arial">The sonication method randomly breaks polymer
chains to produce a varied distribution of products. A scheme with multistage
sonication steps is proposed to identify oligomers and low molecular weight
chitosan based on changes to the degraded product. For each sonication level,
1% (w/v) chitosan in 1% (v/v) aqueous acetic acid was sonicated for 120 min at
60 °C. The products of the sonication treatment were deprotonized by adding an alkali
solution, freeze dried and insoluble product re-sonicated until a low molecular
weight was produced. Low molecular weight chitosan/insoluble products were
characterized with Fourier-transform infrared spectra (FT-IR) and X-ray
diffraction (XRD) to determine the effect of multistage sonication on degree of
deacetylation (DD) and degree of crystallinity. The viscosity of the average
molecular weight of insoluble chitosan was estimated by a viscometric method,
while the degree of polymerization (DP) of the chitosan oligomers (COS) were
determined by end group analysis. The results showed that the molecular weight
of insoluble chitosan decreased and reached a limiting value, (M<sub style="">lim</sub>).
The percent yield of oligoglucosamine of the soluble products increased with
the number of the sonication stages. The degree of crystallinity of insoluble
chitosan increased from 19% to 34.14% while the DD decreased from 82% to 78.1%.</font></span> |
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ISSN: | 2355-2786 2356-4539 |