Modified effects of LDPE/EVA blends by electron beam irradiation

The effect of electron beam irradiation on the properties of low density polyethylene (LDPE, LH0075) and ethylene vinyl acetate (EVA, with 18 %VA) blends were investigated. The improvement of the measured gel content, stress at ultimate, strain at Auto breaks and transition temperatures (Tg, Tm) have confirmed the positive effects on blends but ineffective in density of blends

Rubber Toughened Polyamide 6/ Polypropylene Nanocomposites: Mechanical, Thermal And Morphological Properties

Rubber-toughened nanocomposites (RTNC) consisting series of compatibilized polyamide 6 / polypropylene (PA6/PP) blends, of composition 100/0, 70/30, 50/50, 30/70 and 0/100, polyethylene-octene elastomer (POE) and organophilic modified montmorillonite (organoclay) were produced by melt compounding followed by injection moulding. Polypropylene grafted maleic anhyride (PPgMA) was used as compatibilizer. Subsequently, for PA6/PP (70/30), the POE and organoclay loading was varied between 5 and 20 wt% and 2-6 wt%, respectively. For the optimum particles dispersed in the PA6 matrix, was characterized by scanning electron of a formulation, four different types of elastomer were incorporated into the blends i.e. ethylene-octene elastomer (POE), ethylene-propylene elastomer (EPR), maleated POE (POEgMAH) and maleated EPR (EPRgMAH). For the selected formulation, the nanocomposites were also prepared through different mixing sequence of melt intercalation i.e. direct, two times and two steps method. The mechanical properties were studied through tensile, flexural, Izod impact and fracture toughness testing. The morphology, essentially comprised of PP and POE microscopy (SEM). Wide angle X-ray diffraction (XRD) was used to characterize the formation of the nanocomposites. The thermal properties were characterized by using differential scanning calorimeter (DSC) and thermogravimetry analysis (TGA). The dynamic mechanical were analyzed by using dynamic mechanical thermal analyzer (DMTA)

Preparation and characterisation of polyethylene-octene grafted maleic anhydride-toughened 70:30 PA6/PP/MMT nanocomposites

A series of nanocomposites consisting of a polyamide 6 (PA6) and polypropylene (PP) matrix (70:30) with a maleated polyethylene-octene elastomer (POEgMAH) and organophilic modified montmorillonite (MMT) were prepared by melt compounding in a co-rotating twin-screw extruder followed by injection moulding. The weight fraction of organoclay was adjusted from 2 - 10 wt% by increments of 2 wt% and the weight fraction of POEgMAH was fixed at 10 wt%. POEgMAH was used as an impact modifier as well as compatibiliser in the nanocomposites. Mechanical properties of the blends were investigated by tensile, flexural and impact testing. X-ray diffraction (XRD) was used to characterise the nanocomposites. The thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Addition of 4 wt% organoclay showed the highest tensile and flexural strengths for the blends. The Young's and flexural moduli were also improved with increasing the organoclay concentration but with a corresponding reduction in impact strength and elongation at break. XRD result revealed that the organoclay was dispersed uniformly (exfoliated) although the degree of exfoliation decreased with increasing organoclay content. The DSC analysis showed that the crystallinity of the blends decreased with increasing organoclay concentration. It was shown from the TGA analysis that the thermal stability of the PA6/PP nanocomposites was significantly improved in the presence of impermeable silicate layers in the blends

Toughening polyamide 6 nanocomposites with maleic anhydride grafted polyethylene octene

Rubber toughened nanocomposites consisting of ternary blends of polyamide 6 (PA 6), maleic anhydride grafted polyethylene octene (POEgMAH) and organoclay montmorillonite (MMT) were prepared by melt compounding followed by injection moulding. The organoclay content was kept constant at 4 wt% while the POEgMAH content was varied between 5 to 20 wt%. The mechanical properties were studied through tensile, flexural and impact properties. The scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to examine the morphology of the nanocomposties. The results showed that, the incorporation of 4 wt% organoclay significantly increased the stiffness and strength but at the expense of the toughness. Izod impact measurement indicated that the addition of POEgMAH led to a significant improvement in the impact strength of the nanocomposites. X-ray diffraction analysis (XRD) revealed that an intercalation organoclay silicate layer structure was formed in rubber-toughened PA6 nanocomposites. SEM study revealed a two-phase morphology where POE, as droplets was dispersed finely and uniformly in the PA6 matrix

Thermal and flexural properties of regenerated cellulose(RC)/poly(3- hydroxybutyrate)(PHB)biocomposites

Regenerated cellulose (RC)/ poly(3-hydroxybutyrate) (PHB) composite was prepared via melt compounding with different RC contents from 1 to 7 wt.%. Regenerated cellulose fiber was prepared in NaOH/urea aqueous solution. The properties of the cellulose and the regenerated cellulose were compared using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), and Differential Scanning Calorimetry (DSC). The results of TGA and DSC revealed that the regenerated cellulose had lower thermal properties than cellulose. Meanwhile, the FTIR of regenerated cellulose showed that the intensity portrayed by a few peaks had reduced or disappeared as compared to cellulose. Besides, PHB composites were characterized using TGA and flexural testing. Moreover, thermal stability of the composites insignificantly changed with the incorporation of RC. Improvement in flexural strength and modulus were observed, whereas 3 wt.% was found to be the optimum RC content

Adhesive bonding of thermoplastic polyurethane with metallic wire

Steel wires coated with thermoplastic have found a wider range of application in the field of science and engineering. However, steel-polymer interfaces frequently suffer from poor adhesion strength that is undermining their long-term stability under external stress because of weak interaction between the steel and polymer surfaces. Therefore, the present study aims to investigate the influence of adhesive (Chemlok 213 and Cilbond 49SF) on the adhesion strength of galvanized and ungalvanized steel wire coating with thermoplastic polyurethane (TPU). Surface treatments including grinding with sandpaper, thermal oxidation and degreasing with alkaline solution were done on the steel wire substrate prior to coating by compression molding and extrusion process. The adhesion was characterized with a single wire pullout test and field emission scanning microscopy (FESEM). The experimental results confirmed that Cilbond 49SF adhesive with sandpaper grinding treated wire outperformed all other surface treatments tested. In comparison of the processes, compression molding process has an upper hand over the extrusion process because it provide an avenue for sufficient control of curing time required for optimum setting of the adhesive. Thus, this study presents a tailored procedure which can easily fits in to a production line to produce a polymer coated steel wire rope

Mechanical, Rheological, and Bioactivity Properties of Ultra High-Molecular-Weight Polyethylene Bioactive Composites Containing Polyethylene Glycol and Hydroxyapatite

Ultrahigh-molecular-weight polyethylene/high-density polyethylene (UHMWPE/HDPE) blends prepared using polyethylene glycol PEG as the processing aid and hydroxyapatite (HA) as the reinforcing filler were found to be highly processable using conventional melt blending technique. It was demonstrated that PEG reduced the melt viscosity of UHMWPE/HDPE blend significantly, thus improving the extrudability. The mechanical and bioactive properties were improved with incorporation of HA. Inclusion of HA from 10 to 50 phr resulted in a progressive increase in flexural strength and modulus of the composites. The strength increment is due to the improvement on surface contact between the irregular shape of HA and polymer matrix by formation of mechanical interlock. The HA particles were homogenously distributed even at higher percentage showed improvement in wetting ability between the polymer matrix and HA. The inclusion of HA enhanced the bioactivity properties of the composite by the formation of calcium phosphate (Ca-P) precipitates on the composite surface as proven from SEM and XRD analysis

Structural and characterization studies of insoluble Thai Bombyx mori silk fibroin films

Bombyx Mori fiber consists of two major proteins which are fibroin and sericin. The silk fibroin (SF) is the core structural protein of silk fiber. SF protein structures comprise of primary and secondary structures; where the primary structure contains series of amino acid and secondary structure with Silk I refers to the water-soluble and Silk II, high β sheet extent which is insoluble. This study was conducted to compare the structural and characterization of insoluble Thai Bombyx Mori SF with different types of post-treatement. Thai silk cocoons, which were degummed and dissolved in 9.3 M LiBr solution at 60 °C. The obtained SF solutions were dialyzed and purified. SF films were prepared by solution casting and immersing in methanol and ethanol, followed by water annealing in water saturated vacuum. Post-treatment was purposely done to regenerate and induce of the β sheet structure to enhance the insolubilities and the stabilities properties of the SF films. The SF films structural conformation, characterization and thermal stability were characterized. Attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR) showed that SF films were presented in a more stable form after ethanol post treatment, which also supporting by X-ray diffraction (XRD) analysis which indicated the tendency to higher structural organization. Thermal analysis resutls showed that SF was thermally stable and improved after post treatment. The contact angle of post treated SF increased the hydrophobicity of the films. The thai SF films could be the promising candidate for applications in tissue regeneration, optical devices, and flexible electronic displays with the possibility to control the SF structure and properties

Effect of hybrid FRP confinement on tin slag polymer concrete compressive strength

This study investigates the strength enhancement of Tin Slag Polymer Concrete (TSPC) under hybrid GFRP and CFRP confinement in comparison with mono GFRP and CFRP confinement on TSPC circular short column samples. Hybrid FRP confinement is prepared by wrapping TSPC with GFRP followed by CFRP both 1 layer using epoxy Sikadur 330 as matrix binders with 50 mm overlap. Compression test was performed on unconfined TSPC (TSPC-UC), TSPC with GFRP confinement (TSPC-GF), TSPC with CFRP confinement (TSPC-CF) and TSPC with hybrid FRP confinement (TSPC-HB) with 1mm/ min loading rate. The test results have revealed that the ultimate strengths are 59.19 MPa (TSPC-UC), 85.54 MPa (TSPC-GF), 108.77 MPa (TSPC-CF) and 124.59 MPa (TSPC-HB). The corresponding compressive strain measured at ultimate compressive strength is 0.0300 (TSPC-UC), 0.0453 (TSPC-GF), 0.0398 (TSPC-CF) and 0.0588 (TSPC-HB). Stress versus strain curve has shown that compared to TSPC-UC, externally strengthen sample with GFRP, CFRP and Hybrid FRP have enhanced TSPC strength with slight different behavior. TSPC-GF has less strength enhancement with larger strain while TSPC-CF provide larger strength enhancement but with lower strain. However, TSPC-HB has shown the highest strength enhancement with larger strain benefit from combined GFRP and CFRP properties. Failure mode of hybrid FRP confinement on TSPC (TSPC-HB) has shown combination of both FRP components failure mode (TSPC-GF and TSPC-CF) as in rupture pattern and delamination. The results of this study has provide findings on the effect of hybrid FRP confinement on TSPC circular column sample in close expectation based on literatures

Thermal and mechanical properties of ultrahigh molecular weight polyethylene/high-density polyethylene/polyethylene glycol blends.

Blends of ultrahigh molecular weight polyethylene (UHMWPE) with high-density polyethylene (HDPE) provide adequate mechanical properties for biomedical application. In this study, the mechanical and thermal properties of UHMWPE/HDPE blends with the addition of polyethylene glycol (PEG) prepared via single-screw extruder nanomixer were investigated. The UHMWPE/HDPE blends exhibit a gradual increase in strength, modulus, and impact strength over pure polymers, suggesting synergism in the polymer blends. The elastic and flexural modulus was increased at the expense of tensile, flexural, and impact strength for the blends containing PEG. The degradation temperature of UHMWPE was improved with the incorporation of HDPE due to good thermal stability of HDPE. HDPE improved the dispersibility of PEG in matrix, consequently reduced the surface area available for the kinetic effects, and reduced the degradation temperature. The morphology analysis confirmed the miscibility between UHMWPE and HDPE and the changes in polymer structure with the presence of PEG modify the thermal behavior of the blends. The mechanical properties of the blends that are underlying values for the design of implant material show the potential used as biomedical devices