RESEARCH
Nagata Laboratory are focusing on designing novel functional materials by using various "compounding" techniques. We use many kinds of compounding methods (from micro to macro scale, isotropic or anisotropic, etc), which are important to control the structure and functionality of composite materials. Current research topics are physical (mechanical, thermal, and electrical) properties of polymer materials, recycling methods of plastics, and environmentally friendly polymers (biocompatible and biodegradable).
Functional polymer materials by using compounding technique
Thermally and/or electrically conductive polymer composites
using a phase separation technique.
In order to prepare the thermally and/or electrically conductive polymer materials, compounding appropriate fillers (metals, ceramics, and carbon materials) to matrix polymers are needed. However, the addition of a large amount of fillers causes the loss of flexibility and processability of polymer materials. Our research group has established an effective method to decrease the percolation threshold value of the fillers by using a phase separation phenomenon of polymer blends, which helps to control the dispersion state of fillers and the formation of conductive paths.
Bio-based polymer composites
Recently, bio-based polymers have been paid much attention as environmentally friendly materials. Especially, cellulose nanofiber (CNF), which is derived from cell walls of wood and plants, is one of the most attractive materials due to its abundant resource amount and excellent mechanical properties. However, it is difficult to obtain high-performance CNF/polymer composites because hydrophilic CNF and hydrophobic polymers are hardly miscible. Our group has been developing CNF-based functional materials such as surface-functionalized CNF/polymer composites and CNF/inorganic filler/polymer multi-component materials, which draw a potential of CNF effectively. Other research projects about bio-based polymers such as chitosan and sericin are also in progress.
Recycling techniques for plastics
In general, the degradation of plastic products does not proceed in nature, and the disposal of plastic waste is a serious problem for our society. Our group studies the novel physical recycling method for cross-linked polymers and functional polymer materials derived from plastic wastes.