Preparation and characterization of biodegradable polycaprolactone/multiwalled carbon nanotubes nanocomposites

Abstract

Blends of the biodegradable polycaprolactone (PCL) and multiwalled carbon nanotubes (MWNTs) were prepared by means of a melt blending method. To conquer the poor compatibility between PCL and MWNTs, the acrylic acid grafted polycaprolactone (PCL-g-AA) and the multihydroxyl functionalized MWNTs (MWNTs-OH) were used as alternatives for the preparation of blends. As the comparison between PCL-g-AA/MWNTs-OH and PCL/ MWNTs blends, the former gave much better thermal and mechanical properties than the latter; for examples, 77 C increase in the initial decomposition temperature and 13.3MPa in the tensile strength at break with the addition of only 5 wt %, due to the formation of ester groups through the reaction between carboxylic acid groups of PCL-g-AA and hydroxyl groups of MWNTs-OH. Finally, the optimal amount of MWNTs-OH was 5 wt % because excess MWNTs-OH caused separation of the organic and inorganic phases and lowering their compatibility.

Review on PCL, PBS, and PCL/PBS blends containing carbon nanotubes

“…The carbon nanotube agglomerates act as stress concentration points in the polymer matrix and can, in some cases, reduce the mechanical properties of the original polymer [39]. Functionalized MWCNTs nanocomposites gave much better mechanical properties than non-functionalized MWCNTs nanocomposites, which was ascribed to a better dispersion of the functionalized MWCNTs in the PCL matrix compared to the non-functionalized MWCNTs [59,60,68]. The mechanical properties such as tensile modulus, compressive modulus, tensile strength, storage modulus and elastic modulus increased with increasing MWCNTs content up to 0.5 wt%.…”

“…However, the properties were more improved for the f-MWCNTs than for the pristine MWCNTs nanocomposites [41,62,68]. The improvement of these properties was related to the better dispersion of the f-MWCNTs in the polymer matrix that provided more uniform stress distribution, minimized the presence of stress-concentration centres, and increased the interfacial area for stress transfer from the polymer matrix to the MWCNTs [39,59,60,62,68]. Increasing the MWCNTs content above 0.5 wt% (especially for pristine MWCNTs) resulted in a decline in the mechanical properties of the nanocomposites.…”

“…The extent of interaction depends on how well the filler is dispersed in the matrix [27]. Several authors evaluated the mechanical and thermo-mechanical performance of pristine and functionalized MWCNTs (f-MWCNTs) in PCL nanocomposites [39,59,60,62,68]. Generally, non-functionalized MWCNTs existed as agglomerates, because of the van der Waals forces and electrostatic interactions between the carbon nanotubes.…”

“…In previous research [46,60,64,[67][68][69], different functional groups such as N-methylpyrrolidine, carboxyl and hydroxyl, urethane, phenylmethanol, primary amine groups and 2-hydroxyethylbenzocyclobutene were used to functionalize MWCNTs. In some cases, the MWCNTs were not modified [40,50,66,69].…”

Covalently linked biocompatible graphene/polycaprolactone composites for tissue engineering

“…Polycaprolactone's unique mechanical and chemical properties have resulted in its extensive commercial development for biomedical and materials applications. [15][16][17] The addition of an electrically conducting filler, such as graphene, opens up a number of further possible applications, such as conducting substrates for the electrically stimulated growth of cells.…”