Alkylation Of Chinese Bamboo Flour And Thermoplasticity

Natural bamboo flours were chemically modified by acetylation and cyanoethylation using microwaves and ultrasound irradiation for imparting bamboo flours soluble and fusible properties. The modification conditions were optimized and the composition, microstructure and thermal behavior were also preliminarily studied by FTIR, DSC and SEM. Then, the modified bamboo flours were mixed with PCL, PE or PVC in the Haake rheometer to prepare bamboo/plastic composites. The rheological properties, mechanical properties and phase interface of the complex materials were studied and the optimized formula and processing technic were finally determined.Results showed that the bamboo flours possessed thermoproptity after acetylation and cyanoethylation in some degree just as the traditional high polymer materials. The ultrasound could greatly shorten the retreat time of bamboo to 1/6 as that of traditional method and improve the efficiency of the experiments. Acetylated bamboo flour(MB) showed glass transition in 265℃. Especially, with a temperature of 130℃and a pressure of 10 MPa the acetylated bamboo flours could be molded into sheets. The cyanoethylacion reaction time was reduced from 3 hours to 0.5 hours at the same weight gain percent (40%) as that of conventional method.Without adding coupling agent and anti-friction agent, the MB/PCL composite prepaired by Haake rheometer owned excellent mechanical properties and good interface compatibilities. Even the content of the MB up to 35%, the tensile-strength of the material was 10MPa and the elongation at break could maintain 400% or above. Meanwhile, the cyanoethylated bamboo flours (NB)/PE and NB/PVC composites were also processed by the Haake rheometer. The materials appeared to be close-grained and the interface between the two phases was obscure.