The Effect of Carbon Black Grades in Tyre Tread Compounds

In this study carbon black filler was added to the various formulations of tyre tread compounds. The carbon black grades chosen were N339/N375 and N550/N660. The compounds were characterised with respect to their rheological and physical properties. It was found that the carbon black grades of N375 and N339 could be substituted readily with minimal effects to the hardness, rebound resilience, tensile and tear strength. On the other hand, the carbon black of N550 could not be directly substituted with N660 as it affects the hardness and resilience of the vulcanizate

Sustainable green poly(lactic acid) (PLA)/eggshell powder (ESP) biocomposites

Poly(lactic acid), which is most commonly referred to by its acronym PLA, is a polymer that may be recycled and naturally deteriorated. It is also inherently fragile and has a low impact strength. PLA, when mixed with eggshells powder, can produce a PLA/ESP composites. The purpose of this study was to investigate the physical characteristics of PLA composites that contained ESP or calcium carbonate (CaCO3). Extrusion melt mixing in a twin-screw extruder was used in conjunction with PLA with different ESP concentrations to develop this eco-friendly and sustainable nanocomposite material. The blended compounds were allowed to reach room temperature before being formed into thin films with dimensions of 20 mm in width, 100 mm in length, and 5 mm in thickness. These films were put through a series of tests to determine their mechanical, thermal, and chemical properties. Tests including stress-strain properties, FTIR, thermogravimetric analysis (TGA), and scanning electron microscopy were performed on the films (SEM)

Poly(lactic acid)/acrylonitrile butadiene styrene nanocomposites with hybrid graphene nanoplatelet/organomontmorillonite: effect of processing temperatures

This work reports the preparation and characterization of poly(lactic) acid/acrylonitrile butadiene styrene/graphene nanoplatelets/Cloisite C20A montmorillonite (PLA/ABS/GnP/C20A) nanocomposites via melt blending. The clay is hybridized with graphene to increase its dispersion in the polymer matrix. The melt processing temperatures play a vital role in the properties of the resulting nanocomposites in dictating the extent of thermal stability and dispersion of the fillers. The hybrid nanocomposites were characterized for stress-strain, thermal, chemical, and morphological properties. The findings were that there was an increase in the mechanical properties in terms of tensile strength and Young’s modulus with the PLA/ABS/GnP/C20A at the high-temperature profile having the highest values of 43.1 MPa and 2533 MPa. The elongation at break increases slightly, due to the brittle properties of GnP. It was found that the dispersion of the fillers increased with increasing temperature profiles, as revealed by the morphological analysis by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The void size was also observed to be smaller and more homogenous with increasing temperature. However, in terms of thermal degradation analysis, the addition of fillers increases its thermal stability as the decomposition onset temperature increases by 22.58C

Modification of structure and properties of well-dispersed dendrimer coated multi-walled carbon nanotube reinforced polyester nanocomposites

This work reveals the structure and properties of dendrimer coated multiwall carbon nanotube (DMWCNT) reinforced unsaturated polyester resin (UPR) nanocomposite. Rheology, as well as the shear thinning behavior of nanosuspension exhibits the dispersion of DMWCNT in UPR matrix. The Raman spectra of DMWCNT-UPR nanocomposites along with the Fourier-transform infrared (FTIR) spectra of DMWCNT and DMWCNT-UPR nanocomposites indicate the interaction between DMWCNT and UPR in the nanocomposite system. Additionally, the surface morphology of DMWCNT and DMWCNT-UPR nanocomposites reveals well dispersion of DMWCNT in DMWCNT-UPR nanocomposites. X-ray diffraction (XRD) profile demonstrates structural properties of pristine UPR and nanocomposites. The Transmission Electron micrograph and Field Emission Scanning Electron micrograph show the fractured surface morphologies of DMWCNT-UPR nanocomposites. Comparative stress-strain behavior shows the deformation mechanism of DMWCNT-UPR nanocomposites

Mechanical and thermal properties of binary blends poly lactic acid (PLA) and recycled high-density polyethylene (rHDPE)

In this work, plastic bottles made of high-density polyethene (HDPE) have been recycled and blended with poly(lactic acid) (PLA). The aim of the work is to prepare a binary blend of PLA and Recycled HDPE (rHDPE) at 90:10 blend ratio by using a twin-screw extruder. The blends were compression moulded and characterized in terms of mechanical and thermal properties. It was found that the rHDPE increased the tensile modulus of the binary blend. Fracture morphology demonstrated that the blend of rHDPE and PLA is immiscible. In terms of thermal property, as measured by Differential Scanning Calorimetry (DSC), the glass transition temperature of the binary blend showed a lower value, whereas the crystallization process was significantly improved

Toughening Effect of Liquid Natural Rubber on The Morphology and Thermo-Mechanical Properties of the Poly(Lactic Acid) Ternary Blend

In this work, poly(lactic acid) (PLA) was melt blended with liquid natural rubber (LNR) and linear low-density polyethylene (LLDPE) to fabricate a PLA–LNR–LLDPE ternary blend. The torque rheology demonstrates the melt mixing behavior of PLA–LLDPE binary and PLA–LNR–LLDPE ternary blends. Mechanical properties of ternary blend illustrate the highest toughness as compared to neat PLA and PLA–LLDPE binary blend. Fracture morphology reveals the plastic deformation behavior in the ternary blend which is illustrated in TEM micrograph. The cold crystallization temperature of the ternary blend appears at a lower temperature as compared to the binary blend. The thermal stability of PLA is improved due to blending with LLDPE and LNR. The ternary blend exhibits greater storage modulus in the glassy state as well as in the rubbery state as compared to neat PLA and binary blend. Finally, LNR performed as an effective compatibilizer between PLA and LLDPE

Preparation and Characterization of Low-density Polyethylene/Thermoplastic Starch Composites

In this study, sago starch was physically blended with low-density polyethylene (LDPE) via the melt blending process followed by injection molding to produce LDPE/sago starch (LPS) composites. The sago starch content was varied from 5 to 30 wt% of LDPE. The addition of starch to LDPE reduced the melt flow rate (MFR), the tensile strength, and impact strength, whereas the tensile modulus, flexural strength, and flexural modulus increased. To improve poor mechanical properties of the LPS, LDPE/glycerol thermoplastic starch (LPGTS) or LDPE/2:1 mixture of glycerol and urea thermoplastic starch (LPMTS) was used in this study. The effect of compatibilizer (maleic anhydride) on properties of the LPMTS specimens was also investigated. The LPS, LPGTS, LPMTS, and maleic anhydride treated LPMTS (LPMTSM) samples were analyzed for the MFR, mechanical properties (tensile, flexural, and impact tests), thermal (TGA and DSC), and morphological properties. As a result, the incorporation of plasticizers or compatibilizer into LPS caused the considerable improvement in MFR and mechanical properties. Moreover, the presence of compatibilizer produced better properties for the LPMTSM sample than for the other samples, indicating better dispersion and homogeneity of starch to the matrix. In addition, thermal stability, DSC, and phase morphology were carried out for different LPS samples

Environmentally Degradable Sago Starch Filled Low-density Polyethylene

Degradable native low density polyethylene (LDPE) and modified LDPE films containing 5–30 wt% of sago starch, and LDPE with prodegradant additives in the form of a master batch (MB) in the amounts of 30% starch were prepared by twin screw extrusion followed by injection molding. Studies on their mechanical properties such as tensile strength and elongation at break and biodegradation were carried out by tensile test and exposure to hydrolysis, fungi environment as well as by natural weathering and burial in soil. The presence of high starch contents had an adverse effect on the tensile properties of the blend films. High starch content was also found to increase the rate of biodegradability of the films. The characteristic parameters of the environment were measured during the period of degradation and their influence on degradation of LDPE was discussed. Changes in weight, morphology, thermogravimetric analysis (TGA) and tensile properties of polymer samples were tested during the experiment performed

Improvement of dispersion of different carbon nanotubes (CNTS) in liquid polymer resin for composites

This research presents a non-destructive modification of multi-walled carbon nanotube (MWCNT) and fabrication of MWCNT reinforced unsaturated polyester resin (UPR) nanocomposite. In this work, pre-dispersion of MWCNTs was performed in the tetra hydro furan (THF) solvent. In addition, pre-dispersion and post- dispersion time was optimized as 1.5 hour and 2 hour, respectively. The pre-dispersed MWCNT reinforced UPR (THF-MWCNT-UPR) nanocomposite exhibited better properties as compared to directly dispersed MWCNT reinforced UPR (MWCNT-UPR) nanocomposite. The optimum amount of MWCNT was evaluated through mechanical properties of nanocomposites contained 0.05 to 0.5 wt% MWCNT. The experimental tensile modulus (TM) of 0.3 wt% MWCNT reinforced 0.3CNT-UPR nanocomposite linearly fitted with Halpin –Tsai equation. Therefore, 0.3 wt% MWCNT was suggested as the optimum quantity. The nondefect modification of MWCNT was carried out with hyper branched polyester (HBP) and shellac (SL) functional polymers. The structural and thermal properties of 10 wt% HBP and SL coated HBCNT and SLCNT was noticeably improved as compared to pristine MWCNT. Moreover, 10 wt% HBP and SL coated HBCNT and SLCNT nanotubes remarkably reduced the curing temperature of nanosuspensions. Therefore, 10 wt% was considered as the optimum amount of HBP and SL to modify MWCNT. Optimum HBP coated MWCNT incorporated (OHBPCNT-UPR) nanocomposite became stiff. Conversely, optimum SL coated MWCNT incorporated (OSLCNT-UPR) nanocomposite became tough as compared to MWCNT reinforced nanocomposite. Different ratios of HBCNT and hydroxyl (OH) functionalized MWCNT (OHCNT) were incorporated in UPR to fabricate hybrid (HBOHCNT-UPR) nanocomposites. The ratio of HBCNT and OHCNT was optimized as 2:1 through the curing behavior of hybrid nanosuspensions. The comparative study was carried out among non-covalent and covalent functionalized as well as hybrid MWCNT reinforced UPR nanocomposites. Hybrid MWCNT incorporated nanosuspension exhibited the lowest curing temperature as compared to non-covalent and covalent functionalized MWCNT incorporated nanosuspensions. The hybrid nanocomposite exhibited the highest stiffness among nanocomposites which was individually fabricated with HBCNT and OHCNT. The mixture of non-covalent functionalized and covalent functionalized MWCNT jointly reinforced the properties of UPR. From this research 5 journal and 3 conference papers has been published