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Crosslinking of agar by diisocyanates
Amit Kumar Sonker1, Mezigebu Belay1, Kalpana Rathore1
1Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
Carbohydrate Polymers
|October 6, 2018
Summary
Crosslinking agar with diisocyanates (DI) significantly reduces water absorption and enhances tensile strength. Aromatic diisocyanates, like DDI, offer superior properties compared to aliphatic ones, resulting in a more robust and thermally resistant material.
Area of Science:
- Materials Science
- Polymer Chemistry
Background:
- Agar, a natural polysaccharide, exhibits high water absorption, limiting its applications.
- Crosslinking is a common strategy to modify polymer properties.
Purpose of the Study:
- To investigate the effect of diisocyanate (DI) crosslinking on agar's properties.
- To compare the efficacy of aromatic (DDI) and aliphatic (HDI) diisocyanates in modifying agar.
Main Methods:
- Agar was crosslinked using 4,4'-diphenyl diisocyanate (DDI) and 1,6-hexamethylene diisocyanate (HDI).
- Water uptake, tensile strength, and thermal resistance of crosslinked agar were evaluated.
- Hemocompatibility and cytotoxicity assays were performed.
Main Results:
- Crosslinking significantly reduced water uptake: DDI-agar (33.6%) and HDI-agar (43.6%) vs. native agar (206%).
- DDI-crosslinked agar exhibited higher tensile strength (45.3 MPa) than HDI-agar (30.6 MPa) and native agar (31.7 MPa).
- Aromatic diisocyanates provided better thermal resistance and crosslinking efficiency due to higher reactivity.
Conclusions:
- Diisocyanate crosslinking effectively enhances agar's mechanical and thermal properties while reducing water absorption.
- DDI-crosslinked agar demonstrates superior performance, making it a promising material for various applications.
- The crosslinked agar exhibits hemocompatibility and non-toxicity.
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