Heterogeneous materials in which the characteristic length scale of the filler material is in the nanometer range-i.e., nanocomposites-is currently one of the fastest growing areas of materials research. Polymer nanocomposites have expanded beyond the original scope of polymer-nanocrystal dispersions for refractive-index tuning or clay-filled homopolymers primarily pursued for mechanical reinforcement, to include a wide range of applications. This article highlights recent research efforts in the field of structure formation in block copolymer-based nanocomposite materials, and points out opportunities for novel materials based on inclusion of different types of nanoparticles. The use of block copolymers instead of homopolymers as the matrix is shown to afford opportunities for controlling the spatial and orientational distribution of the nanoelements. This, in turn, allows much more sophisticated tailoring of the overall properties of the composite material.

Block copolymer nanocomposites : Perspectives for tailored functional materials

Summary: More than twenty years have passed since we invented PCN, in which only a few wt.-% of silicate is randomly and homogeneously dispersed in the polymer matrix. When molded, these nanocomposites show superior properties compared to those of pristine polymers. The number of papers on PCN has increased rapidly in recent years, reaching over 500 in 2005 alone. Being pioneers of this new technology, we review its history relative to the following epochal events: 


In 1985 we invented nylon 6-clay hybrid (NCH), the first PCN.


In 1989, cars equipped with a NCH part were launched.


In 1997, Gilman found revolutionary fire retardancy in NCH.


In 1997, a PP-clay nanocomposite was prepared using a compatibilizer.


In 1998, a compounding method for producing PCN was completed.


In 2002, Haraguchi invented a revolutionary nanocomposite hydrogel.



So far, only nylon-clay nanocomposites have been used in practice, but other PCN will become increasingly useful in the future.

SEM of etched NCH film.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/mame.200700001

Twenty Years of Polymer‐Clay Nanocomposites

http://eprints.adm.unipi.it/524/1/EUROPOL%2DD%2D08%2D01110%2D1.pdf

Rheological Properties of Asphalt/SBS/Clay Blends

A series of TPU nanocomposites were prepared by incorporating organically modified layered silicates with controlled particle size. To our knowledge, this is the first study into the effects of layered silicate diameter in polymer nanocomposites utilizing the same mineral for each size fraction. The tensile properties of these materials were found to be highly dependent upon the size of the layered silicates. A decrease in disk diameter was associated with a sharp upturn in the stress−strain curve and a pronounced increase in tensile strength. Results from SAXS/SANS experiments showed that the layered silicates did not affect the bulk TPU microphase structure and the morphological response of the host TPU to deformation or promote/hinder strain-induced soft segment crystallization. The improved tensile properties of the nanocomposites containing the smaller nanofillers resulted from the layered silicates aligning in the direction of strain and interacting with the TPU sequences via secondary bonding. This...

Segmented Polyurethane Nanocomposites: Impact of Controlled Particle Size Nanofillers on the Morphological Response to Uniaxial Deformation

Detailed analysis of dynamic mechanical properties of TPU nanocomposite: The role of the interfaces

We propose a novel scheme for controlling the nanostructures of organic polymer materials by using nanoparticles as templates and we also demonstrate a spontaneous formation of arranged microdomain structures in block copolymers controlled by clay silicate layers dispersed at the nanometer level. Block copolymer-layered silicate nanocomposites were prepared by melt compounding of hydrogenated styrene-butadiene-styrene triblock copolymer with organophilic layered silicates intercalated with stearylammonium. Their morphologies were observed by transmission electron microscopy. The triblock copolymer microdomain structures were found to be arranged along the dispersed silicate layers. Such structures did not exist in the original block copolymer. TEM images suggest that the formation of the arranged microdomain structures are induced and controlled by the interaction of the silicate layers, which act as templates. It is thought that these controlled nanostructures were formed through the selective absorption of the polystyrene segments on dispersed silicate surfaces followed by segregation of each segment.

Arimitu Usuki

Papers

Arranged Microdomain Structure Induced by Clay Silicate Layers in Block Copolymer-Clay Nanocomposites