Characterization and properties of epoxidized natural rubber toughened poly (lactic acid) reinforced by graphene nanofiller

The unvulcanized and dynamically vulcanized poly (lactic acid)/ epoxidized natural rubber (PLA/ENR, PLA/ENR-TPV) blends and a new ternary nanocomposite system based on PLA/ENR/graphene and PLA/ENR-TPV/graphene were prepared. The effect of ENR and ENR-TPV contents (10-30 wt%) on the morphological and mechanical properties of the blends were investigated. On the top of that, the effects of graphene loadings (0-2.0 phr) and different processing methods on the morphological, mechanical and thermal properties of nanocomposites were evaluated. The blends were prepared using a nano-single screw extruder whereas PLA/ENR/graphene and PLA/ENR-TPV/graphene nanocomposites were prepared using both nano-single screw extruder and internal mixer. The tensile and the impact test were carried out to determine the mechanical properties, while the differential scanning calorimeter (DSC) and the thermogravimetric analysis (TGA) were used to investigate the thermal properties. Meanwhile, scanning electron microscope (SEM) and field emission scanning electron microscope (FESEM) were used to observe the morphologies of the blends and nanocomposites. The PLA/ENR and PLA/ENR-TPV blends at 10 wt% of ENR and ENR-TPV loadings showed the highest impact and tensile properties. Thus were selected as basic materials to prepare the nanocomposites. The PLA/ENR/graphene nanocomposites prepared using the internal mixer gave higher mechanical properties and thermal stability than the nano-single screw extruder. The tensile strength, elongation at break and impact strength of the PLA/ENR/graphene and PLA/ENR-TPV/graphene nanocomposites were increased until 1.0 phr of graphene loading. Beyond that these mechanical properties decreased. The PLA/ENR-TPV/graphene nanocomposite exhibited higher tensile strength, elongation at break and impact strength compared with PLA/ENR/graphene nanocomposite. The thermal stabilities of the PLA/ENR/graphene and PLA/ENRTPV/ graphene nanocomposites prepared by both nano-single screw extruder and an internal mixer have improved as the graphene loading increased. From DSC analysis, it was found that the melting temperature, Tm remained unchanged while heat of fusion, AHm and degree of crystallinity, Xc increased as the graphene loading increased since graphene acted as a nucleating agent. The FESEM micrographs revealed good dispersion and distribution of graphene in the PLA/ENR and PLA/ENR-TPV matrix at 1.0 phr of graphene loading that resulting in good interaction between the components. Furthermore, the nanocomposites that prepared using the internal mixer showed better dispersions and distributions of graphene in the matrix thus further enhancing the properties of the nanocomposites

The effect of dynamic vulcanization on the morphological and mechanical properties of the toughened poly (lactic acid)/epoxidized natural rubber

Poly (lactic acid)/epoxidized natural rubber (PLA/ENR) was prepared by using counter-rotating twin-screw extruder. For dynamic vulcanization process, ENR was compounded with 3 phr of N, N’-m-phenylenebismaleimide (HVA-2) as a crosslinking agent. The aim of this study is to determine the effect of unvulcanized and dynamically vulcanized of ENR on the properties of PLA/ENR blend. The blending of PLA with ENR was prepared with the various composition of ENR (0 wt% to 30 wt%). The morphology and mechanical properties of the blends were investigated by using scanning electron microscope (SEM), tensile test, and impact test. The unvulcanized blend produced a co-continuous morphology of PLA and ENR and the dynamically vulcanized blend shows the dispersed ENR rubber particles in PLA continuous matrix. For both systems, the tensile strength value was dropped with the increasing amount of ENR content. The impact strength of both systems shows the maximum value at 20 wt% of ENR content. However, dynamically vulcanized PLA/ENR blend shows a better tensile strength and impact strength value as compared with unvulcanized blend

A novel recycled polyethylene terephthalate/polyamide 11 (rPET/PA11) thermoplastic blend

This work explores a novel blend of recycled polyethylene terephthalate/polyamide 11 (rPET/PA11). The blend of rPET/PA11 was introduced to enhance the mechanical properties of rPET at various ratios. The work’s main advantage was to utilize rPET in thermoplastic form for various applications. Three different ratios, i.e. 10, 20 and 30 wt.% of PA11 blend samples, were prepared using a twin-screw extruder and injection moulding machine. The mechanical properties were examined in terms of tensile, flexural and impact strength. The tensile strength of rPET was improved more than 50%, while the increase in tensile strain was observed 42.5% with the addition of 20 wt.% of PA11. The improved properties of the blend were also confirmed by the flexural strength of the blends. The flexural strength was increased from 27.9 MPa to 48 MPa with the addition of 30 wt.% PA11. The flexural strain of rPET was found to be 1.1%. However, with the addition of 10, 20 and 30 wt.% of PA11, the flexural strain was noticed as 1.7, 2.1, and 3.9% respectively. The impact strength of rPET/PA11 at 20 wt.% PA11 was upsurged from 110.53 to 147.12 J/m. Scanning electron microscopy analysis revealed a dispersed PA11 domain in a continuous rPET matrix morphology of the blends. This work practical implication would lead to utilization of rPET in automobile, packaging, and various industries

Mechanical and thermal properties of sepiolite strengthened thermoplastic polymer nanocomposites: A comprehensive review

Sepiolite (Si12Mg8O30(OH,F)4].(H2O)4·8H2O) is a valuable filler with an enormous capacity to be used in thermoplastic composites, substituting costly reinforcing fillers, such as graphene and CNTs. Sepiolite strengthened polymers nanocomposite materials have encouraged the field of research and ventures because of their strengthening ability and bio-compatibility in polymer composites. Sepiolite shows remarkable characteristics over various fillers due to its higher specific surface area and channel type structure. Numerous investigations were performed to decide different properties of Sepiolite strengthened polymer composites in various applications, for example, tensile strength, flexural strength, impact strength, stiffness, thermal, flammability, thermo-mechanical, and morphological. This review paper focuses on the mechanical and thermal properties of sepiolite strengthened polymer nanocomposites. Generally, it can be determined that the properties of sepiolite loaded thermoplastic polymer composites mainly depend on filler content, matrix, bond interaction, shape, size of sepiolite particles. Further assessment and development are required to expand its utilization in several applications. These comprise the utilization of nano-size sepiolite made synthetically as functionalized filler in thermoplastics