A Comparative Analysis of the Reinforcing Efficiency of Silsesquioxane Nanoparticles versus Apatite Nanoparticles in Chitosan Biocomposite Fibres

Kean Wang,Rangika De Silva,Pooria Pasbakhsh,Kheng Goh

doi:10.3390/jcs1010009

Abstract

A comparative analysis of the effects of polyhedral oligomeric silsesquioxane (POSS) and hydroxyapatite (HA) for reinforcing chitosan (CS) is given here. Wet-spun CS nanocomposite fibres, blended with HA or POSS nanoparticles, at varying concentrations ranging from 1 to 9% (w/w) were stretched until rupture to determine the mechanical properties related to the elasticity (yield strength and strain, stiffness, resilience energy) and fracture (fracture strength strain and toughness) of the composite. Two-factor analysis of variance of the data concluded that only the fracture-related properties were sensitive to interaction effects between the particle type and concentration. When particle type is considered, the stiffness and yield strength of CS/POSS fibres are higher than CS/HA fibres—the converse holds for yield strain, extensibility and fracture toughness. With regards to sensitivity to particle concentration, stiffness and yield strength reveal trending increase to a peak value (the optimal particle concentration associated with the critical aggregation) and trending decrease thereafter, with increasing particle concentration. Although fracture strength, strain at fracture and fracture toughness are also sensitive to particle concentration, no apparent trending increase/decrease is sustained over the particle concentration range investigated here. This simple study provides further understanding into the mechanics of particle-reinforced composites—the insights derived here concerning the optimized mechanical properties of chitosan composite fibre may be further developed to permit us to tune the mechanical properties to suit the biomedical engineering application.

Highlights

To overcome the limitations of biopolymers, such as low stiffness and strength, and to enable these materials to have wide applicability, inorganic particulate fillers are often blended with the biopolymer to form a composite material that possesses enhanced stiffness and strength [1,2,3]
To clarify which types of particle would exhibit advantages over the other, as well as to broaden our understanding of the underlying mechanisms of nanoparticulates for reinforcing chitosan composite material, this study investigates the effects of particle type, at varying particle concentrations, on the chitosan composite elasticity and fracture
As for the elasticity-related parameters (i.e., E, σY, εY and uY), the results suggest that the main effects of particle concentration and particle type on these parameters may be interpreted independently of one another. (B) With regards to effects from particle type, by and large the σY and E of CS/polyhedral oligomeric silsesquioxane (POSS) fibres are higher than CS/HA fibres but CS/HA fibres possess higher εY, εU and uF than CS/POSS fibres

Summary

Introduction

To overcome the limitations of biopolymers, such as low stiffness and strength, and to enable these materials to have wide applicability, inorganic particulate fillers are often blended with the biopolymer to form a composite material that possesses enhanced stiffness and strength [1,2,3]. This study is concerned with chitosan (CS) biopolymer, a linear polysaccharide that can be derived from the alkaline N-deacetylation of chitin [4,5]. CS has been a subject of great interest owing to its biocompatibility-related advantages, notably anti-clotting, biodegradability [4,9], antimicrobial and low toxicity (even in blends) [10,11,12]. It can be used for medical products such as bandages and implants, or grafted with compounds to yield chelating agents that can be used in water filters [10,11,12]

Methods

Results

Conclusion