title: Fabrication and mechanical properties of composite based on β-chitin and polyacrylic acid.
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 4-6nm 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 2100MPa respectively, compared to 65MPa 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.
authors.affiliation: Enikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, Profsoyuznaya st. 70, 117393, Moscow, Russia; National Research Centre "Kurchatov Institute", Akademika Kurchatova pl. 1, Moscow, 123182, Russia. Electronic address: pishi.olge@gmail.com.
authors.forename: Olga I
authors.initials: OI
authors.lastname: Bogdanova
authors.affiliation: National Research Centre "Kurchatov Institute", Akademika Kurchatova pl. 1, Moscow, 123182, Russia. Electronic address: dmitkonpol37@yandex.ru.
authors.forename: Dmitry K
authors.initials: DK
authors.lastname: Polyakov
authors.affiliation: Enikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, Profsoyuznaya st. 70, 117393, Moscow, Russia; National Research Centre "Kurchatov Institute", Akademika Kurchatova pl. 1, Moscow, 123182, Russia. Electronic address: streltsov.dmitry@gmail.com.
authors.forename: Dmitry R
authors.initials: DR
authors.lastname: Streltsov
authors.affiliation: National Research Centre "Kurchatov Institute", Akademika Kurchatova pl. 1, Moscow, 123182, Russia. Electronic address: alya.kulebyakina@gmail.com.
authors.forename: Alevtina I
authors.initials: AI
authors.lastname: Kulebyakina
authors.affiliation: National Research Centre "Kurchatov Institute", Akademika Kurchatova pl. 1, Moscow, 123182, Russia; Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, Moscow 119333, Russia. Electronic address: orekhov.anton@gmail.com.
authors.forename: Anton S
authors.initials: AS
authors.lastname: Orekhov
authors.affiliation: National Research Centre "Kurchatov Institute", Akademika Kurchatova pl. 1, Moscow, 123182, Russia; Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky pr. 59, Moscow 119333, Russia. Electronic address: a.vasiliev56@gmail.com.
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Vasiliev
authors.affiliation: Case Western Reserve University, Cleveland, OH, 44106, United States. Electronic address: jxb6@case.edu.
authors.forename: John
authors.initials: J
authors.lastname: Blackwell
authors.affiliation: Enikolopov Institute of Synthetic Polymeric Materials, Russian Academy of Sciences, Profsoyuznaya st. 70, 117393, Moscow, Russia; National Research Centre "Kurchatov Institute", Akademika Kurchatova pl. 1, Moscow, 123182, Russia. Electronic address: s-chvalun@yandex.ru.
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Chvalun
keywords: Nano-composite; Polyacrylic acid; Polymerization filling; Reinforcing; Whisker; β-chitin