You can add a lot of fillers. If interested in natural composites, you might check also on some surface treatment in order to improve mechanical strength.

Dear Manickam,

You may apply these

1. Addition of microfillers

2. Plasticizers you have to see compatibility

3. Nano-materials will also work

4. Metal powder also works in some cases

etc.

Please have a look at

eXPRESS Polymer Letters 2007, 1(9), 546-575, the review on cellulosic nanocomposites can be freely downloaded from http://www.expresspolymlett.com/

try ozonating it