YAMAGUCHI Laboratory
<Major Research Areas>Rheology, polymer physics, polymer processing

Design of High-performance
Polymer Materials Based on
Applied Rheology

Research activity

Design of High-performance Polymer Materials through Control of Rheological Behavior

　　Rheology, the science of deformation and flow, is efficient for research on materials showing complicated mechanical responses. Further, rheological properties are quite sensitive to the molecular architecture and higher-order structure of polymeric materials. This is why R&D sections of companies require specialists in rheology.
　　Since rheology is a practical science, the materials used as research subjects are wide-range, including plastic, fiber, rubber, paint, food, cosmetics, bio-materials and nanocomposites. Expertise and technology in this area are also needed in the processing of materials into finished products.
　　Our laboratory is designing new polymers with applied rheology as a means of material design. Specifically, we are carrying out the four types of research outlined below:

1Research and development of high-performance molecular composites

　　We aim to design high-performance polymer composites through sophisticated control of molecular aggregation state. Our research area includes the development of composites with carbon-nanotube, the design of new foams, and the design of highly functional polyolefin by adding a small quantity of organic additives (increase in transparency, improvement of impact strength, and control of mechanical anisotropy).

2Study of the effect of molecular architecture on rheological properties and processability

　　We aim to control rheological properties at the molecular level for developing new functions and improving processability of polymers. We are researching the development of highly functional polyester materials and investigating the rheological control of branched polymers.

3Material design of biomass-based polymers using molecular composites

　　We are engaged in the development of high-performance, highly functional biomass-based polymers, such as polylactide, poly(butylene succinate), poly(3-hydroxybutyrate), and cellulosederivative.

4Development of novel functional polymers

　　We aim to design new functional polymers, such as new sound-absorber, self-repairing polymers, and functional embossed-films on which concavities and convexities are controlled at the nano-order level.

Equipment

Cone-and-plate rheometer, capillary rheometer, melt-tension detector, dynamic mechanical analyzer, scanning electron microscope, transmission electron microscope, atomic force microscope, optical microscope, stress-optical coefficient measuring device, X-ray diffractometer, differential scanning calorimeter, gel permeation chromatograph, single-screw extruder, injection-molding machine, internal mixer, tensile machine

The main research achievements in the past five years

1. M. Yamaguchi, Y. Irie, P. Phulkerd, H. Hagihara, S. Hirayama, S. Sasaki, Plywood-like Structure of Injection-Moulded Polypropylene, Polymer, 51 (25), 5983-5989 (2010).
2. M. Yamaguchi, K. Okada, A. M. Mohd Edeerozey, T. Iwasaki, and K. Okamoto, Extraordinary wavelength dispersion of orientation birefringence for cellulose esters, Macromolecules, 42, 9034-9040 (2009).
3. H. Yoon, K. Okamoto, and M. Yamaguchi, Carbon nanotube imprinting on a polymer surface, Carbon, 47, 2840-2846 (2009).
4. M. Yamaguchi, S. Ono, K. Okamoto, Interdiffusion of dangling chains in weak gel and its application to self-repairing material, Mater. Sci. Eng. B, 162 (3), 189-194 (2009).
5. M. Yamaguchi, Morphology and Mechanical Properties in iPP/Polyolefin-Based Copolymer Blends, in Polyolefin Blends, Eds., D. Nwabunma and T. Kyu, Chap. 9, Wiley, New York (2007).