Fabrication and mechanical properties of composite based on β-chitin and polyacrylic acid. (10th February 2017)

• Record Type: Journal Article
• Authors: Bogdanova, Olga I.; Polyakov, Dmitry K.; Streltsov, Dmitry R.; Kulebyakina, Alevtina I.; Orekhov, Anton S.; Vasiliev, Alexander L.; Blackwell, John; Chvalun, Sergey N.
• Is Part Of: Carbohydrate polymers. Volume 157(2017)
• Page Start: 1496
• Page End: 1502
• Publication Date: 2017-02-10
• Subjects: Nano-composite -- β-chitin -- Polyacrylic acid -- Whisker -- Polymerization filling -- Reinforcing; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2016.11.032
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: The nanofibrils of 4–6 nm in diameter and several μm in length were isolated. Composites polyacrylic acid/β-chitin were prepared by polymerization in situ . Prepared nanocomposites revealed superb mechanical properties at high humidity. Polyacrylic acid and β-chitin in composite are chemically crosslinked. Percolation threshold is reached at composite of 3% of chitin. Abstract: Squid β-chitin has been exfoliated in aqueous acrylic acid (AA), after which a composite film of chitin microfibrils in polyacrylic acid (PAA) has been prepared by in situ polymerization of the AA. The segregated chitin fibrils in the composite are 4–6 nm in diameter, with an aspect ratio >250. After drying cast films of the composites containing 1, 2 and 3% (w/w) chitin at 140 °C for four hours, there was a dramatic resistance to swelling in water, in that the dried films showed only small changes in shape and properties after four hours immersed in water.The most profound impact of the reinforcement on the mechanical properties is observed at high relative humidity (RH), when the PAA is in the rubbery state. At 97.5% RH and room temperature, the elastic moduli of the composites with 1, 2 and 3% (w/w) chitin were 150, 230 and 2100 MPa respectively, compared to 65 MPa for pure PAA. The main contribution to the filler-reinforcing effect is the high aspect ratio of fibrils and non-covalent interactions, but the stability in water suggests the presence of chemical bonding between the PAA and chitin.