Help with solvents for lignin-based bioplastic production

Hi,

I am a furniture designer-maker and I came across this study, which I am trying to replicate in my workshop (in west London). I am trying to make a series of works using this material and I think I need some help understanding the chemistry that is occurring in the setup I have.

I unfortunately was unable to get choline chloride as I am not part of a research/university institution and the suppliers only have one tier of membership (where protected chemicals would be available). Through some research I decided to try Citric Acid and Glycerol as a DES (with Oak dust as the lignin source), although it has not resulted in a usable bioplastic (I believe due to the strength of the solvent being unable to break down the lignin bonds). The result has been more of a biocomposite 'plastic'/'resin' sheet which is not what I am after.

I would love to be able to talk to someone who understands more of the science that is occurring and if at all possible, help me achieve a true lignocellulosic bioplastic. Is there another possible solvent that will be able to break down the lignin bonds in the wood?

Thank you