Preparation And Characterization Of Alkylated Chitosan Film

Alkylated chitosan film is an important polymer film,with antibacterial,biodegradable,biocompatible and other excellent performance,which has been widely used in the field of medicine.Therefore,the preparation of alkylated chitosan film has been widely concerned by the majority of scholars.In this paper,chitosan(Mr:117×105,D.D.:95.2%)was used to prepare ethylated chitosan with microwave alkalization method.Ethylated chitosan samples with different degrees of substitution were obtained by changing the reaction time of the alkylation process.The ethylated chitosan films were prepared in acetic acid(HAc)conventional system.The mechanical properties of the film were investigated to find high degree of substitution and high performance ethylated chitosan raw materials.The results showed that the degree of substitution was 23.5% and the breaking strength of ethylated chitosan film was 220.5 MPa when the reaction time was 4 h.The ethylated chitosan films were prepared in HAc conventional system and the binary ionic liquid system according with different mass ratios of [Acmim]Cl and [Gly]Cl.And the process optimization was carried out.Experiment results showed that the breaking strength of ethylated chitosan film,breaking elongation percentage and nitial modulus were 266.1 MPa,17.0%,and 2.3 GPa separately in HAc system.In ionic liquid system,breaking strength of ethylated chitosan film,breaking elongation percentage,and initial modulus were 168.6 MPa,11.4%,and3.6 GPa respetively.Therefore,the film in HAc system had superior mechanical properties,smoother surface,better breathability,greater contact angle and degree of swelling than that in the ionic liquid system film.Compatibility evaluation indicated that both film had good blood compatibility.Butylated chitosan with different degree of substitution was obtained by changing the reaction time of the alkylation process.The results showed when the reaction time was 4 h,the degree of substitution was 27.4% and the breaking strength of butylated chitosan was 227.5 MPa.The butylated chitosan films were prepared in HAc conventional system and the binary ionic liquid system with different mass ratios of [Acmim]Cl and [Gly]Cl.And the optimum conditions were obtained.The results indicated that in HAc system the breaking strength of butylated chitosan film was 291.2 MPa,breaking elongation percentage was 12.5%,and initial modulus was 1.9 GPa.In ionic liquid system,breaking strength of butylated chitosan film,breaking elongation percentage and initial modulus was 191.5 MPa,12.7%,and 3.4 GPa separately.Apparently,the film in HAc system had superior mechanical properties,smoother surface,better breathability,greater contact angle and degree of swelling than that in the ionic liquid system film.Compatibility evaluation showed that both film had good biocompatibility.Octylated chitosan samples with different degrees of substitution were obtained by changing the reaction time of the alkylation process.The results showed that the degree of substitution was 23.9% and the breaking strength of octylated chitosan was 231.6 MPa when the reaction time was 5 h.The Octylated chitosan films were prepared in HAc conventional system and the binary ionic liquid system with different mass ratios of [Acmim]Cl and [Gly]Cl.And the optimum conditions were obtained.The results indicated that the breaking strength of octylated chitosan film was 232.0 MPa,breaking elongation percentage was15.8%,and initial modulus was2.0 GPa in HAc system.In ionic liquid system,breaking strength of octylated chitosan film was 228.2 MPa,breaking elongation percentage 8.2%,initial modulus 3.6 GPa.Based on above data,the film in HAc system had superior mechanical properties,smoother surface,better breathability,greater contact angle and degree of swelling than that in the ionic liquid system film.Both film had good blood compatibility according to the compatibility evaluation.Compared with films prepared in different liquid system,butylated chitosan film had the best mechanical properties in HAc system,and octylated chitosan film had the best mechanical properties in ionic liquid system.In general,the film in HAc system had higher swelling degree and breathability than that in ionic liquid film,which is more easily degraded and absorbed as medical material.