The effect of chain extender on viscosity and mechanical properties of poly (buthylene terepthalate) blending with recycled poly(ethylene terephthalate)-glass fiber composite

In this study, multi-functional styrene-acrylic oligomers was used as the chain extender in poly butylenes terephthalate/recycled glass-filled polyethylene terephthalate (PBT/RGF-PET) blends. Normally, usage of recycled plastics is favourable but somehow, during the reprocessing causes loss of properties. Thus, chain extender was added to restore the viscosity and mechanical properties of PBT/PET blends due to the incorporation of recycled poly (ethylene terephthalate) has lowered viscosity and molecular weight. Chain extender at 0.50 and 0.65 wt% was added into 50/50 PBT/RGF-PET using melt compounding method to compare viscosity and mechanical properties with virgin PBT and RGF-PET, respectively. Addition of chain extender has improved the viscosity of the PBT/RGF-PET which was in relation to the increment of molecular weight. When 0.50 w\.% of chain extender was added to PBT/RGF-PET blend at ratio of 50:50, the flexural modulus increased 9.6% to 3530 1.1Pacompared to the original flexural modulus at 3220 1.1Pa. This showed that a small amount of chain extender was successfully to improve the flexural modulus. The increment of molecular weight as induced by the addition of chain extender improved the impact resistance of the PBT/RGF-PET from 17 to 20.3 kJ m"? for addition of 0.50 wt.% chain extende

Effects of electron beam irradiation on properties of corn starch undergone periodate oxidation mechanism blended with polyvinyl alcohol

This work was performed to examine the properties of pristine PVOH and PVOH-starch blends under exposure of different irradiation dosages. The periodate oxidation method was used to produce dialdehyde starch. The application of low dosages of electron beam irradiation (=10 kGy) has improved the tensile strength by forming crosslinking networks. However, the tensile strength drastically declined when radiated at 30 kGy due to the reduction of available hydroxyl groups inside polymer matrix for intermolecular interaction. Also, the incorporation of corn starch and dialdehyde starch has significantly reduced the melting temperature and enthalpy of melting of PVOH blends due to cessation of the hydrogen bonding between PVOH and starch molecules. The crystallite size for deflection planes (1 0 1), (1 0 1) and (2 0 0) for all PVOH blends was significant reduced when irradiated. The electron beam irradiation has also weakened the hydrophilic characteristic of all PVOH blends as evidenced in infrared and microscopy analysis

A review of copolymerization of green house gas carbon dioxide and oxiranes to produce polycarbonate

Carbon dioxide is highly stable and low reactivity element which is known to cause greenhouse effect of the Earth. Over the decades, researches have been conducted to utilize abundant carbon dioxide to turn into value added products while reducing its impact to the environment. One of the approaches is reacting carbon dioxide with oxiranes to produce polycarbonate. The low reactivity characteristic of carbon dioxide requires effective and efficient catalysts to make the copolymerization possible. This review highlights the major development in the catalytic copolymerization process of oxiranes and carbon dioxide. Particularly, the important characteristics of zinc, aluminium, chromium, cobalt, cadmium, manganese and rare earth metal with variety of ligands catalysts have been thoroughly discussed. The future research prospects which involve working in the copolymerization area of nanocatalysis and supercritical fluid have been analysed also. In overall, continual exploration of catalysis and reaction package for copolymerization of carbon dioxide is important in order to achieve better improvement of process in future

Mechanical properties of talc and calcium carbonate filled PVC

The main aim of this work was to compare the mechanical properties of calcium carbonate (CaCO3) and talc filled PVC. Talc and CaCO3 are common fillers in plastics such as PVC to reduce cost and modify mechanical properties. The PVC resin and additives were blended by using high speed laboratory mixer to produce a homogenized PVC formulation. Then, the dry blended samples were melted and sheeted on the two roll mill machine. The sheeted PVC compounds were compression moulded into impact and flexural test specimens. Flexural and impact tests were then performed to determine and compare the mechanical properties of both PVC composites. Talc filled PVC composite gave the highest flexural modulus but the lowest impact strength compared to all grades of CaCO3 filled PVC composites. The SM90 CaCO3 gave the most optimum properties in trems of impact strength and flexural modulus compared to all grades of CaCO3

Structure-properties relationship of hybrid talc/calcium carbonate filled impact modified PVC composites

The main objective of this study was to investigate and compare the mechanical properties and processability of single-filler and hybrid poly(vinyl chloride) (PVC) composites. Calcium carbonate (CaCO3) was used in this study to improve the impact strength of PVC while talc was used to improve stiffness. Filler was added into PVC at a constant loading level of 30phr. SM90 showed the most optimum properties in terms of impact strength and flexural modulus among all grades of CaCO3 selected for hybrid study. Tests specimens were prepared by using dry blending, two roll milling and compression moulding processes. Flexural, impact and tensile tests were then performed to determine and compare the effect of fillers on mechanical properties of PVC composites. Talc filled PVC composite showed the highest flexural modulus but the lowest impact strength. The impact strength of hybrid PVC composites gradually increased with increasing SM90 content, but the flexural modulus showed an opposite behaviour. The flexural strength and impact strength were the highest among the hybrids when the talc/SM90 weight ratio was 20:10. The distribution and dispersion of the fillers in PVC matrix were observed by using SEM. The well dispersion and interfacial adhesion of SM90 and talc particles in PVC matrix had contributed and helped in improving the stiffness and the impact strength of PVC composite. The fusion time of hybrid talc/SM90 filled PVC composite gradually increased as the talc content was gradually replaced by SM90. However, the hybrid (10phr talc: 20phr SM90) filled PVC composite showed the longest fusion time among all PVC composites. TGA, DSC and HDT tests were also carried out to investigate the thermal properties of PVC composites. The incorporation of talc and CaCO3 were found to improve the thermal stability and rigidity of PVC composites

Mechanical properties of tale and calcium carbonate filled PVC

The main objective of this investigation was to study and compare the thermal rigidity, thermal stability, and processability of poly(vinyl chloride) (PVC) composites filled with single fillers of talc and uncoated ground CaCO3 (SM 90) or a hybrid filler consisting of talc/SM 90. To produce the composites, the PVC resin, fillers, and other additives were dry-blended in a laboratory mixer before being milled into sheets by using a tworoll mill. Test specimens were prepared by compression molding, after which the thermal properties and processability of the composites were determined. Single and hybrid filler loadings used were fixed at 30 phr (parts per hundred parts of resin). Talc-filled PVC composite showed slightly better thermal stability and rigidity than the composite filled with SM 90, and its thermal stability and rigidity slightly decreased with SM 90 content increasing from 5 to 25 phr in order to replace talc filler in the hybrid composites. The fusion time of talc-filled PVC composite was shorter than that of SM 90-filled PVC composite; thus, the fusion time of hybrid composites increased with increasing SM 90

Enhancement of mechanical and thermal properties of (Poly[vinyl alcohol])-Dialdehyde starch composites via the incorporation of montmorillonite nanofillers

This study was conducted to investigate the effects of nano‐size montmorillonite (MMT) in poly(vinyl alcohol)‐(dialdehyde starch) (PVOH‐DAS) blending system. DAS was initially synthesized through periodate oxidation method, followed by a solution casting procedure to prepare a PVOH‐DAS‐MMT blend hybrid. Increasing the amount of MMT significantly increased the thermal decomposition temperatures of PVOH‐DAS blends. This is because the intercalated MMT particles in the PVOH‐DAS matrix could restrict the diffusion of oxygen and volatile gases throughout the PVOH‐DAS matrix by delaying the decomposition temperature. The incorporation of MMT particles into the PVOH‐DAS matrix has significantly increased the d‐spacing and interchain separation of peaks (001) and (002). The effective intercalation of PVOH‐DAS matrix into interlayer galleries of MMT particles could increase the interlayer galleries gap distance. Increasing the amounts of MMT has significantly increased the mechanical properties of all PVOH‐DAS blends. The intercalation effect of MMT particles in the PVOH‐DAS matrix could improve the compatibility between PVOH and DAS phases in the PVOH‐DAS matrix by effectively transferring applied stress throughout the polymer matrix

Investigation of Calcination of Sepia officinalis Cuttlefish Bone for Reinforcement of Polyvinyl Alcohol Added Nano-Size Montmorillonite

This study aims to investigate the effects on calcination of Sepia officinalis cuttlefish bone (cuttlebone) to enhance reinforcement of polyvinyl alcohol (PVOH) added with nano-size montmorillonite (MMT) blends as potential bio-compatible materials. The polyvinyl alcohol-cuttlebone-montmorillonite nanocomposites were prepared using the solution casting method. Calcined cuttlebone particles were added to the PVOH matrix at different amount of 2 and 5 parts per hundred resin (phr) along with MMT ranging from 1 to 3 phr. Results showed that the tensile strength of cuttlebone-added PVOH-MMT composites at fixed 1 phr MMT was observed to be marginally lower when the cuttlebone increased from 2 phr to 5 phr due to the poor distribution of agglomerated particles. Nevertheless, at higher loading level of MMT, it was found that the addition of cuttlebone at 5 phr exhibited a reinforcing effect in PVOH-MMT blends. This is consistent with the scanning electron microscopy observation, where dispersion of a higher amount of cuttlebone in PVOH-MMT blends was observed to be more homogeneous than a lower amount of cuttlebone. Moreover, based on the X-ray diffraction analysis, the addition of cuttlebone significantly enhanced the intercalation effect of MMT particles in the PVOH matrix. Furthermore, the observation from infrared spectroscopy shows the amount of hydroxyl group for all composites reduced gradually with the increasing amount of cuttlebone. The addition of cuttlebone showed a “red shift” effect, indicating the formation of hydrogen bonds induced by cuttlebone. Lastly, lower enthalpy of melting was detected in relation to higher loading level of cuttlebone embedded in PVOH-MMT blends through differential scanning calorimetry. In conclusion, the blending of cuttlebone in PVOH-MMT is favorable to obtain better properties of composites

Study of Thermal Effect on the Mechanical Properties of Nylon 610 Nanocomposites with Graphite Flakes That Have Undergone Supercritical Water Treatment at Different Temperatures

This study investigates the thermal effect of supercritical water treatment at different temperatures (150, 175, 200 °C) and semi-vacuum state (−0.08 MPa) on graphite flakes which are then incorporated into nylon 610. The treatment is deemed to increase the surface activity of nanofillers through the formation of oxygen-containing functional groups. X-ray diffraction (XRD) analysis indicated that the crystal structure of the flakes remained similar before and after supercritical water treatment. Fourier transform infrared spectroscopy (FTIR) also showed the presence of hydrogen bonding between the flakes and the polymer matrix through the appearance of amide bands. The intensity of the amide peaks is higher for nanocomposites with treated flakes than untreated ones. Furthermore, scanning electron microscopy (SEM) showed that at higher wt%, aggregation will occur, which leads to a weakening in physical properties. The tensile strength of nanocomposites with treated flakes decreased with increasing wt%, while those with untreated flakes increased with increasing wt%. Young’s modulus of all the nanocomposites generally increased with increasing wt%. The highest tensile strength obtained is 967.02 kPa, while that of neat nylon 610 is 492.09 kPa. This enhancement in mechanical properties can be attributed to the intact structure of the graphite flakes and the interaction between the flakes and the nylon 610 matrix. A higher temperature of water treatment was discovered to cause higher oxidation levels on surface of the nanofillers but would result in some structural damage. The optimum nylon 610 nanocomposite synthesized was the one that was incorporated with 1.5 wt% graphite flakes treated at 150 °C and −0.08 MPa, as it has the highest tensile strength