TY - JOUR
T1 - Amphiphilic cellulose nanocrystals for aqueous processing of thermoplastics
AU - Onyianta, Amaka J.
AU - Etale, Anita
AU - Koev, Todor T.
AU - Eloi, Jean-Charles
AU - Khimyak, Yaroslav Z.
AU - Eichhorn, Stephen J.
N1 - Acknowledgments: S.J.E. and A.J.O. would like to thank the Engineering and Physical Sciences Research Council (EPSRC), grant no. EP/V002651/1, for funding. The authors are grateful to Prof T. Kondo of Kyushu University, Japan, for providing the PP microparticles. T.T.K. acknowledges the support of the UKRI Future Leaders Fellowship awarded to M. Wallace (MR/T044020/1). We are grateful to the University of East Anglia’s Faculty of Science NMR facility. S.J.E. and A.J.O. acknowledge Prof. Tony McNally of the International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, for access to the injection molding kit and to Engr Martin Worrall for the training and support in using the instrument. Electron microscopic studies were carried out in the Chemical Imaging Facility at the University of Bristol, with equipment funded by EPSRC under Grant ″Atoms to Applications″ Grant ref. (EP/K035746/1).
PY - 2022/11/11
Y1 - 2022/11/11
N2 - Conventional composite formulation of cellulose nanocrystals (CNCs) with thermoplastics involves melt compounding or in situ polymerisation. In this rather unconventional approach, polypropylene (PP) microparticles were finely suspended and stabilized, at varying weight loadings, in aqueous suspensions of amphiphilic CNCs to enable adsorption of the nanoparticles onto the thermoplastic. In order to achieve these suspensions, CNCs were modified with either octyl or hexadecyl groups. These modifications imparted hydrophobic properties to the CNCs, hence increasing interfacial adhesion to the PP microparticles. The modification, however, also retained the sulfate half ester groups that ensured dispersibility in aqueous media. The CNCs were evidently coated on the PP microparticles as revealed by confocal microscope imaging and had no detrimental effect on the melt properties of the PP-based composites. The approach is demonstrated to increase the Young’s moduli of CNC-thermoplastic composites prepared in optimum suspension loadings of 0.5 wt. % octyl-modified and 0.1 wt % hexadecyl-modified CNCs. This procedure can be extended to other thermoplastics as the ability to aqueously process these composites is a major step forward in the drive for more sustainable manufacturing.
AB - Conventional composite formulation of cellulose nanocrystals (CNCs) with thermoplastics involves melt compounding or in situ polymerisation. In this rather unconventional approach, polypropylene (PP) microparticles were finely suspended and stabilized, at varying weight loadings, in aqueous suspensions of amphiphilic CNCs to enable adsorption of the nanoparticles onto the thermoplastic. In order to achieve these suspensions, CNCs were modified with either octyl or hexadecyl groups. These modifications imparted hydrophobic properties to the CNCs, hence increasing interfacial adhesion to the PP microparticles. The modification, however, also retained the sulfate half ester groups that ensured dispersibility in aqueous media. The CNCs were evidently coated on the PP microparticles as revealed by confocal microscope imaging and had no detrimental effect on the melt properties of the PP-based composites. The approach is demonstrated to increase the Young’s moduli of CNC-thermoplastic composites prepared in optimum suspension loadings of 0.5 wt. % octyl-modified and 0.1 wt % hexadecyl-modified CNCs. This procedure can be extended to other thermoplastics as the ability to aqueously process these composites is a major step forward in the drive for more sustainable manufacturing.
U2 - 10.1021/acsapm.2c01623
DO - 10.1021/acsapm.2c01623
M3 - Article
VL - 4
SP - 8684
EP - 8693
JO - ACS Applied Polymer Materials
JF - ACS Applied Polymer Materials
SN - 2637-6105
IS - 11
ER -
