Inorganic whiskers method

The surface modification methods of inorganic whiskers mainly include the wet method, dry method, in situ polymerization, sol-gel method, surface coating and coupling agent modification, self-assembly method, and so on. 

In the in situ polymerization method, first inorganic whiskers are evenly dispersed in monomers and then polymerized using a method similar to bulk polymerization. In this method, surface modification of whiskers and preparation of composites take place at the same time. 

There are two different methods of surface modification evaluation of inorganic whiskers the direct method and the indirect method. 

Dong Jin. Preparation methods and application progress of inorganic whisker materials. Fine Chemical Industrial Raw Materials and Intermediates, (10) 23-27, 2010. 

Preparation Methods of Composite Material Filled with Inorganic Whiskers... 

In the solution dispersion method, first matrix resin is dissolved in solvent then treated inorganic whiskers are added and well stirred until evenly dispersed in solution. Next solvent is removed or polymerized, and a composite material is obtained. 

In situ polymerization is a method in which inorganic whiskers are evenly dispersed in reactive monomers (or their soluble prepolymers) and then are polymerized using a method identical to bulk polymerization. At the beginning of the reaction, monomers are prepolymerized and then deposited on the surface of whiskers after the prepolymers increasingly aggregate to obtain composite materials filled with whiskers. 

At present, research on polymers modified with inorganic whiskers focuses mainly on mechanical performance analysis and further theoretical analysis is relatively rare. In recent years, the finite element method has been widely used in such studies, which can provide a necessary theoretical basis for the micro-structure design of material and macro performance improvement. 

Wei X, Wang K, Chen J (2011) The functional inorganic composites. Prog Chem 23 42-52 Rinki K, Shipra T, Dutta PK et al (2009) Direct chitosan scaffold formation via chitin whiskers by a supercritical carbon dioxide method a green approach. J Mater Chem 19 8651-8655... 

The thermal stability of a material sometimes is represented by the temperature of 5% decomposition and usually can be determined by a thermogravimetric method. Because inorganic fillers have a high melting point, adding inorganic fillers into resin can improve the heat resistance of the polymer. A composite material is prepared by filling calcium carbonate whiskers into PP material. The thermal decomposition temperature (5% decomposition) of the composite material increased from 366.7 to 400.6°C as the whisker content was enhanced. 

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