Nagata Laboratory are forcusing on designing the novel functional materials by using a 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 invironmetally friendly polymers (biocompatible and biodegradable).

Functional polymer materials by using compounding technique

Thermally and/or electrically conductive polymer composites

Thermally conductive composite materials by
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, addition of a large amount of fillers causes the loss of flexibility and processability of polymer materials. Our research group have established a effective method to decrease the percolation threshold value of the fiilers by using a phase separation phenomenan of polymer blends, which helps to control the dispersion state of fillers and the formation of conductive paths.

Bio-based polymer composites

SEM image of CNF/polymer composite.

Recently, bio-based polymers have paid much attensions as environmentally friendly materials. Especially, cellulose nanofiber (CNF), which derived from cell walls of woods and plants, are one of the most attractive materials due to its abundant resource amount and excellent mechanical properties. However, it is difficult to obtain the high performance CNF/polymer composites because hydrophilic CNF and hydrophobic polymers are hardly miscible. Our group have 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, degradations of plastic products donot proceed in nature, and the disposal of plastic wastes is serious problem for our society. Our group studies the novel physical recycling method for cross-linked polymers, and functional polymer materials derived from the plastic wastes.