Characterization of Biomaterials Based on Microfibrillated Cellulose with Different Modifications

The purpose of this study was to develop a new kind of high strength, low thermal expansion material employing microfibrillated cellulose obtained from bamboo fibers. A possible application for such material is, for example, as a viable alternative to ceramics for probe cards industrially employed in wafer chip testing. High strength, low coefficient of thermal expansion, and low moisture absorption are among the different requirements for this application. The effect of processing conditions over mechanical properties of the obtained biocomposite was investigated; different levels of fiber homogenization were analyzed and morphology changes were monitored by optical and scanning electron microscopy examinations. Different technologies and treatments were employed to get adequate characteristics. In order to control thermal expansion or mechanical properties, nanoparticles of amorphous silica or bacterial cellulose were added to the material. The remarkable water absorption of cellulosic fibers can have undesirable effects on the mechanical properties and the dimensional stability of the material. The effect of acetylation treatment to reduce water uptake was thus investigated.