Cohesion at cellulosic fibers/mineral matrix interface: Chemical treatments and characterization.

The use of cellulosic fibres as reinforcement in a mineral matrix (in our case based on a mixture of phyllosilicates and of a hydraulic lime) presents two major disadvantages which are linked to the absorbent character of fibres as well as to their thermal degradations. To modify the properties of fibres surface, prior to their introduction in composite material, chemical, mechanical and thermal treatments are generally applied. Particularly, chemical treatments using Sodium Hydroxide solutions and the grafting of organic molecules increases the cohesion at fibres/matrix interface and allow ameliorating the mechanical behavior of the final composite. Our study is concentrated on the modification of the hemp fibres surface by chemical treatments (treatment with NaOH, grafting of organosilanes at different chemical compositions and at different concentrations) as well as the characterizations by different functional and structural techniques (DTA/TGA, ATR-FTIR, NMR and SEM).