A microstructural study of acrylic-modified chitosan by means of PALS and SAXS

P.S. ANBINDER; C. MACCHI; J. AMALVY; A. SOMOZA

Wuhan

Congreso; 17th International Conference on Positron Annihilation; 2015

International Advisory Commitee on Positron Annihilation (IACPA) - Wuhan University (China)

Chitosan is the partially deacetylated form of the chitin, a natural polysaccharide extracted from the crab, shrimps and other crustacean skeleton. This biopolymer has a great potential as packaging material, due to its inherent antimicrobial activity, non-toxicity and biodegradability [1, 2]. Chemical modification of chitosan, specially grafting with different polymers is animportant topic in the production of bio-based materials with enhanced properties. To our study, two chitosan with different deacetylation degrees (DD %) and molecular weights were grafted with different proportions of n-butyl acrylate in a surfactant-free emulsion system. Stable dispersions with high grafting efficiency were obtained. The nanostructure of the casted films (thickness about 100 µm) was studied using positron annihilation lifetime spectroscopy and small angle X-ray scattering. Specifically, samples with different DD%, molecular weights and grafting ratios were measured. The results obtained are discussed in terms of the number and distribution of graft sites and the breaking of the chitosan rigid rod-structure due to grafting.[1] K.V. Harish Prashanth and R.N. Tharanathan, Carbohydr. Polym. 54, 343?351, (2003).[2] J.-W. Rhim and P.K.W. Ng, Crit. Rev. Food Sci. Nutr. 47, 411?433, (2007).