Laccase from aspergillus niger : a novel tool to graft multifunctional materials of interests and their characterization

Abstract EN

In the present study, we propose a green route to prepare poly (3-hydroxybutyrate) [(P(3HB)] grafted ethyl cellulose (EC) based green composites with novel characteristics through laccase-assisted grafting.

P(3HB) was used as a side chain whereas, EC as a backbone material under ambient processing conditions.

A novel laccase obtained from Aspergillus niger through its heterologous expression in Saccharomyces cerevisiae was used as a green catalyst for grafting purposes without the use of additional initiator and / or cross-linking agents.

Subsequently, the resulting P(3HB)-g-EC composites were characterized using a range of analytical and imagining techniques.

Fourier transform infrared spectroscopy (FT-IR) spectra showed an increase in the hydrogenbonding type interactions between the side chains of P(3HB) and backbone material of EC.

Evidently, X-ray diffraction (XRD) analysis revealed a decrease in the crystallinity of the P(3HB)-g-EC composites as compared to the pristine individual polymers.

A homogeneous P(3HB) distribution was also achieved in case of the graft composite prepared in the presence of 2.20--azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a mediator along with laccase as compared to the composite prepared using pure laccase alone.

A substantial improvement in the thermal and mechanical characteristics was observed for grafted composites up to the different extent as compared to the pristine counterparts.

The hydrophobic / hydrophilic properties of the grafted composites were better than those of the pristine counterparts.