Renewable resource-based green composites from recycled cellulose fiber and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) bioplastic.
ABSTRACT Novel "green" composites were successfully fabricated from recycled cellulose fibers (RCF) and a bacterial polyester, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by melt mixing technique. Various weight contents (15%, 30%, and 40%) of the fibers were incorporated in the PHBV matrix. The effect of the fiber weight contents on the thermal, mechanical, and dynamic-mechanical thermal properties of PHBV was investigated and a comparative property analysis was performed with RCF-reinforced polypropylene (PP) composites. The tensile and storage moduli of the PHBV-based composites were improved by 220% and 190%, respectively, by reinforcement with 40 wt % RCF. Halpin-Tsai and Tsai-Pagano's equations were applied for the theoretical modeling of the tensile modulus of PHBV-based composites. The heat deflection temperature (HDT) of the PHBV-based composites was increased from 105 to 131 degrees C, while the coefficient of linear thermal expansion (CLTE) value was reduced by 70% upon reinforcement with 40 wt % RCF. The PHBV-based composites had also shown better tensile and storage moduli and lower CLTE values than PP-based composites. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to study the melting behavior, thermal stability, and morphology of the composite systems, respectively.
Article: Physico-Mechanical and Degradation Properties of Gamma-Irradiated Biocomposites of Jute Fabric-Reinforced Poly(caprolactone)[show abstract] [hide abstract]
ABSTRACT: Jute fabric-reinforced poly(caprolactone) biocomposites (30–70% jute) were fabricated by compression molding. Tensile strength, tensile modulus, bending strength, bending modulus and impact strength of the non-irradiated composites (50% jute) were found to be 65 MPa, 0.75 GPa, 75 MPa, 4.2 GPa and 6.8 kJ/m 2 , respectively. The composites were irradiated with gamma radiation at different doses (50–1000 krad) at a dose rate of 232 krad/hr and mechanical properties were investigated. The irradiated composites containing 50% jute showed improved physico-mechanical proper-ties. The degradation properties of the composites were observed. The morphology was evaluated by scanning electron microscope. INTRODUCTION Fiber-reinforced polymer matrix composites have been used in diverse fields, like sports goods, cars, microlight air-crafts, electronic components, artificial joints, household articles, structural components for many years  . Due to increasing environmental consciousness and legislative authorities, nowadays, the use and disposal of traditional composite materials, made of glass-, carbon-or aramidfi-ber reinforcements embedded in a synthetic matrix like epoxy, unsaturated polyester resins, polyurethanes or phe-nolic resins, is becoming very difficult as they are creating a detrimental effect on the environment. To solve this pro-blem, the development of biodegradable composite materi-als is being encouraged for different types of applications. The main focus is now to use a biodegradable resin as the matrix material with biofibers as the reinforcement, so that the product is an ecofriendly one, with minimum environmental load. By embedding natural reinforcing fibers, such as jute, flax, hemp, and ramie, into a biopoly-meric matrix made of derivatives from cellulose, starch, or lactic acid, for example, new fiber-reinforced materials called biocomposites are being developed  . Since both components are biodegradable, the composite as the inte-gral part is also expected to be biodegradable. Natural fibers have many advantages, for example low weight, renewability, biodegradability, low cost, low density, acceptable specific mechanical properties, ease of separa-tion, and carbon dioxide sequestration  , as compared to the traditional reinforcing fibers. Therefore, they have been looked upon as an eco-friendly and economical alternative to glass fibers. Natural fiber-reinforced composites are making inroads in many application areas including automobiles, housing, packaging, and electronic products  . The composites from natural fibers and conventional polyolefins have been studied extensively  . Nevertheless, the vast use of the fossil-resource-based polymers has induced many environ-mental problems. Therefore, there is an increasing interest in developing ecofriendly green composites or biocompo-sites by reinforcing the biocompatible and biodegradable plastics with the plant-derived natural fibers [5–22] . Recently, aliphatic polyesters have attracted much research interest due to their biodegradability and biocom-patibility  . Poly(caprolactone) (PCL) is one of the typical aliphatic polyesters, and it is fully biodegradable, biocom-patible, and nontoxic to living organisms  . Also, PCL has good resistance to water, oil, solvent, and chlorine. The unique properties of PCL render its potential in biomedical fields, and it has been used in the development of con-trolled drug delivery systems, as well as in surgical sutures and other resorbable fixation devices [13,25] .Polymer-Plastics Technology and Engineering 03/2009; · 1.28 Impact Factor