Micro-fibrillar composites

Taepaiboon P, Junkasem J, Dangtungee R, Amornsakchai T and Supaphol P (2006) In situ micro-fibrillar-reinforced composites of isotactic polypropylene/recycled poly(ethylene terephthalate) system and effect of compatibilizer, J Appl Polym Sci 102 1173-1181. 

Utracki L A (1989) Polymer and Alloy Blends, Hanser Publishers, Munich, Germany. Bhattacharyya D, Eakirov S and Lin R J T (2006) Mechanics of hbril formation in micro-/nano-fibrillar composites produced from polymer blends, 28th Australasian Polym Symp (APS 2006), Feb 5-9, Rotorua, New Zealand. 

Today, conventional polymer composites are important commercial materials with a wide range of applications in many industries e.g., aerospace, automotive, etc.) where highly resistant and lightweight materials are of prime importance. In recent years, however, optimizing the properties of the traditional polymer composites containing micrometer-scale reinforcing entities has reached its limits. The micro- and nanosized fibrillar composites open a large window of opportunities to further improve the mechanical prop-... 

The coir fiber (diameter = 200-240 pm density = 1.2-1.4 g/cm and micro-fibrillar angle = 30°-39°) was obtained from Central Coir Research Institute, Coir Board, Kerala, India. The coconut husk was cut down into small pieces of approximately 10 mm long before making composites. ENR was prepared in the laboratory. Phenol and formaldehyde (37 % w/w) were obtained from E. Merck, India, and used as received. Reagent grade of acetone and toluene were obtained from E. Merck, India. Epichlorohydrin and sodium hydroxide were procured from S.D. Fine Chemicals,... 

In this chapter we have reviewed some of the most important characteristics of cellulose and cellulose based blends, composites and nanocomposites. The intrinsic properties of cellulose such as its remarkable mechanical properties have promoted its use as a reinforcement material for different composites. It has been showed that cellulose is a material with a defined hierarchy that tends to form fibrillar elements such as elementary fibrils, micro fibrils, and macro fibers. Physical and chemical processes allow us to obtain different scale cellulose reinforcements. Macro fibers, such as lignocellulosic fibers of sisal, jute, cabuya, etc. are used for the production of composites, whereas nano-sized fibers, such as whiskers or bacterial cellulose fibers are used to produce nanocomposites. Given that cellulose can be used to obtain macro- and nano-reinforcements, it can be used as raw material for the production of several composites and nanocomposites with many different applications. The understanding of the characteristics and properties of cellulose is important for the development of novel composites and nanocomposites with new applications. 

Agro-based fiber-reinforced composites can absorb a significant amount of moisture, as the water retains in the inter-fibrillar spaces of these fibers [10]. The content of voids and the non-crystalline parts determine moisture absorption [3]. When these fibers are used in composites, the moisture can occupy the spaces in the flaws of the interface between the fiber and the matrix and the micro voids in the composites in addition to the inter-fibrillar spaces of the fibers [10]. The moisture absorption behavior of plant fibers is one of the main concerns related to the utilization in composite applications [24]. The moisture absorption that takes place as a result of the hydrophilic character of the fiber affects the performance of the composite negatively. Moisture uptake results in fiber swelling and this consequently changes the dimensional stability of the... 

It is worth mentioning that compression molding (CM) is not the only way to transform the oriented precursors into fibrillar micro- or nanostructured composites. Chopping the... 

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