Microfibrillar composites

On the basis of the above considerations, one can conclude that by following the approach described a new type of composites - microfibrillar reinforced ones can be obtained from all thermoplastic polymers. Using blends of condensation polymers, a strong self-compatibillzing effect can be achieved due to Interfaclal chemical interactions. Opportunities are also available for continuous controllable changes of the chemical composition and crystallization ability of the matrix. The formation of an interphase drastically Improves the mechanical integrity of drawn blends. 

The principle procedure follows the well known concept of microfibrillar composites (MFCs) [3]. In contrast to the classical composites, microfibrillar reinforced composites... 

The type of fiber, polymer matrix, and coupling agent are of importance in order to improve the mechanical properties of the resulting composites. Also, the performance of the composites depends on several factors, such as chemical composition, microfibrillar, cell dimensions, and the interaction between the fiber and the polymer matrix. The effect of WG on the tensile properties of sisal fibers was reported [75]. The composites were compounded with sisal fibers and polypropylene matrix. The chemical modification treatments for the composites apphed were WG solution and polypropylene-grafted maleic anhydride copolymer. 

AMINO ACID COMPOSITION (EXPRESSED AS RESIDUES PER 1000 TOTAL RESIDUES) OF TYPICAL MATURE ELASTIN, MATRIX COLLAGEN AND MICROFIBRILLAR PROTEIN PREPARATIONS. 

A new type of composite material starting from polymer blends has been developed. Due to the fact that the reinforcing elements are the basic morphological entities of oriented polymers, the microfibrils, these new composites have been named microfibrillar-reinforced composites (MFC) (Evstatiev Fakirov, 1992). MFC, however, clearly differ from traditional composite systems. Since the microfibrils are not available as a separate component, the classical approach to composite preparation is inappropriate for MFC mannfactnring. 

The plant cell wall consists of cellulose microfibrils within a matrix of non-cellulosic polysaccharides, glycoproteins, and phenolics, the types and composition of which are related to the maturity and function of the cell and the plant type. Most non-ceUulosic cell wall components are held into the microfibrillar array by a combination of cross-links, including covalent and non-covalent ones [4]. 

Covas, J. A., O. S. Cameiro, and J. M. Maia. 2001. Monitoring the evolution of morphology of polymer blends upon manufacturing of microfibrillar reinforced composites. International Journal of Polymeric Materials 50 445-A67. 

The cell walls differ among themselves in their composition and orientation of the cellulose microfibrils. In most plant fibres, these microfibrils are oriented at an angle to the normal axis called the microfibrillar angle (Fig. 19.2). The characteristic value for this structural parameter varies from one plant fibre to another. 

Evstatiev, M., Petrovich, S., and Fakirov, S. (1993) Microfibrillar reinforced composites from binary and ternary blends of polyesters and Nylon 6. Macromolecules, 26, 5219 - 5226. 

S. (1996) Morphology of microfibrillar reinforced composites from polymer blends. Polymer, 37, 4455-4463. 

Fakirov, S. (2013) Nano- and microfibrillar single-polymer composites a review. MacromoL Mater. Eng., 298, 9—32. 

S., and Cornish, J. (2011) Comparison of nanofibrillar scaffolds manuhictured by electrospinning and microfibrillar composite technique. PFAM—19. Proceeding of the Fabrication Advanced Materials - XVII, Auckland, New Zealand, January 14-17, 2011. 

Matthews, B.G., and Cornish, J.A. (2011) Novel microfibrillar composite approach towards manufacturing nanoporous tissue scaffolds. Invited Paper, Proceeding of the International Conference on Composposites for 21st Century Current and Future Trends (ICC-CFT 2011), Bangalore, India, January 4-7, 2011. 

A fibrillar polymer-polymer composite consists of an isotropic matrix polymer with fibrils of a second polymer dispersed within it. The idea was developed by Fakirov et al. [40] with the knowledge that drawing of polymers with good molecular orientation enhances their mechanical properties. Depending on the fibril diameters, such composites are referred to as microfibrillar composites (MFCs) or nanofihrillar composites (MFCs). For simplicity, MFCs are discussed because the manufacturing process is essentially the same. One method of creating MFCs is to produce a blend of the two selected polymers in the form of a continuous wire. 

Morphology of PL/VPGA Nano-/Microfibrillar Polymer-Polymer Composites... 

Microfibrillar reinforced composites—new materials fi om polymer blends. Adv. Mater., 6, 395—398. 

L. D. Kimble, D. Bhattacharyya, S. Fakirov, Biodegradable microfibrillar polymer-polymer composites from Poly(L-lactic acid)/poly(glycolic acid), Expr. Polym. Lett, (in press). 

Friedrich, K., Evstatiev, M., Fakirov, S., Evstatiev, O., Ishii, M., and Harrass, M. (2005) Microfibrillar reinforced composites from PET/PP blends processing, morphology and mechanical properties. Compos. Sci. TechnoL, 65, 107—116. 

Kimble, L.D., Fakirov, S, and Bhattacharyya, D. (2014) Poly(L-lactic acid)/poly(glycolic acid) microfibrillar polymer-polymer composites preparation and viscoelastic properties. 30th International Conference of the Polymer Processing Society, Cleveland, OH, 8-12 June, 2014,... 

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