Dear Mukesh Pandey, please go through the following documents. My Regards

https://www.researchgate.net/publication/301316454_Transparent_Blend_of_PolyMethylmethacrylateCellulose_Acetate_Butyrate_for_the_Protection_from_Ultraviolet

https://www.researchgate.net/publication/239534909_Miscibility_of_polymethylmethacrelate_and_cellulose_acetate_butyrate_blends_in_dimethyl_formamide

https://link.springer.com/article/10.1007/s10853-005-6924-2

https://link.springer.com/referenceworkentry/10.1007%2F978-94-007-6064-6_12

Dear Mukesh Pandey, please go through the following documents. My Regards

https://www.researchgate.net/publication/301316454_Transparent_Blend_of_PolyMethylmethacrylateCellulose_Acetate_Butyrate_for_the_Protection_from_Ultraviolet

https://www.researchgate.net/publication/239534909_Miscibility_of_polymethylmethacrelate_and_cellulose_acetate_butyrate_blends_in_dimethyl_formamide

https://link.springer.com/article/10.1007/s10853-005-6924-2

https://link.springer.com/referenceworkentry/10.1007%2F978-94-007-6064-6_12

hi. you can prepare your CAB/PMMA blend by a twin screw.