scholarly journals Preparation and Characterization of Cellulose Nanofibril Films from Wood Fibre and Their Thermoplastic Polycarbonate Composites

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
S. Panthapulakkal ◽  
M. Sain
Keyword(s):  
Thermal Properties ◽  
Tensile Modulus ◽  
Compression Molding ◽  
Strength Properties ◽  
Diameter Distribution ◽  
Cellulose Nanofibril ◽  
Molding Process ◽  
Pulp Fibres ◽  
High Temperature Tensile

The aim of this study was to develop cellulose-nanofibril-film-reinforced polycarbonate composites by compression molding. Nano fibres were prepared from wood pulp fibres by mechanical defibrillation, and diameter distribution of the fibres produced was in the range of 1–100 nm. Nanofibre films were prepared from the nanofibre suspensions and were characterized in terms of strength properties, crystallinity, and thermal properties. Strength and modulus of the nano fibre films prepared were 240 MPa and 11 GPa, respectively. Thermal properties of the sheets demonstrated the suitability of processing fibre sheets at high temperature. Tensile properties of the films subjected to composite-processing conditions demonstrated the thermal stability of the fibre films during the compression molding process. Nanocomposites of different fibre loads were prepared by press-molding nano fibre sheets with different thickness in between polycarbonate sheet at 205°C under pressure. The tensile modulus and strength of the polycarbonate increased with the incorporation of the fibres. The strength of the thermoplastic increased 24% with 10% of the fibres and is increased up to 30% with 18% of the fibres. Tensile modulus of the polycarbonate demonstrated significant enhancement (about 100%).

scholarly journals CHARACTERIZATION OF COMPOSITE CONTAINING LDPE (LOW DENSITY POLY ETHYLENE) AND MODIFIED PINEAPPLE LEAF FIBER

2020 ◽  
Vol 21 (4) ◽  
pp. 184
Author(s):  
Lestari Wardani ◽  
Noerati Noerati ◽  
Doni Sugiyana
Keyword(s):  
Tensile Strength ◽  
Thermal Properties ◽  
Polymer Matrix ◽  
Natural Fiber ◽  
Strength Properties ◽  
Low Density ◽  
Pineapple Leaf Fiber ◽  
Poly Ethylene ◽  
Leaf Fiber

CHARACTERIZATION OF COMPOSITE CONTAINING LDPE ( LOW DENSITY POLY ETHYLENE) AND MODIFIED PINEAPPLE LEAF FIBER. Pineapple leaf fiber could be used as a reinforcing material in natural fiber composites production with a synthetic polymer matrix. The typical problem in this process was the weak bond between the fiber component and the matrix. This study aimed to improve the bonds strength between pineapple leaf fibers and the polymer matrix of LDPE (Low Density Poly Ethylene) by modifying pineapple leaf fibers. The modification of pineapple leaf fibers was carried out through an enzymatic process using the xylanase enzyme. A modified fiber was then used as a fiber component in the composite using a commercial LDPE plastic matrix. Composites were made by the sandwich method using a hotpress machine at a temperature of 130 °C for 10 minutes. The evaluation of the composites were carried out by testing the tensile strength properties using the Tensolab tool and thermal properties using the TGA (Thermal Gravimetry Analysis) instrument. The results of the mechanical properties test of the composite showed the modified pineapple leaf fiber-based composite had a better tensile strength (34.3 MPa) than the untreated pineapple leaf fiber-based composite (30.2 MPa). The results of the thermal properties test showed the decreasing of the mass occurred at temperature of 300-350 °C due to degradation of the fiber,and it completely degraded at temperature of 450 °C.

Mechanical and thermal characterization of polypropylene-reinforced nanocrystalline cellulose nanocomposites

2020 ◽  
pp. 089270572092512
Author(s):  
Mohammad Y Al-Haik ◽  
Saud Aldajah ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Thermal Characterization ◽  
Nanocrystalline Cellulose ◽  
Injection Molding Process ◽  
Mechanical And Thermal Properties ◽  
Molding Process ◽  
Point Bend ◽  
Cellulose Nanocomposites

This article addresses the effect of nanocrystalline cellulose (NCC) on the mechanical and thermal properties of polypropylene (PP). A new approach was adopted to produce mechanically improved and thermally stable PP-NCC nanocomposite. This approach involved producing optimized PP-NCC nanocomposite by adding NCC nanoparticles to PP matrix at different concentrations by means of injection molding process. The aim of this work was to find the optimum NCC concentration to enhance the mechanical and thermal properties of the PP matrix. The mechanical and thermal behavior of PP-NCC nanocomposite was studied by performing three-point bend, nanoindentation, differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and Fourier transform infrared (FTIR) spectroscopy tests. The results showed that the mechanical properties of strength, modulus, and hardness of the nanocomposites increased with the addition of NCC by 6.5%, 19%, and 150%, respectively. DSC results showed that the addition of NCC to PP does not affect the thermal stability (melting temperature). However, TGA showed that upon inclusion of NCC nanoparticles, the thermal stability of the samples improved compared to pure PP except for the 5% added NCC. This is attributed to the presence of NCC rod-like particles that dissipated heat by generating tortuous paths, as depicted in the SEM results and verified by FTIR results.

Mechanical and thermal characterization of grafted PP-NCC nanocomposites

2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik
Keyword(s):  
Thermal Properties ◽  
Interfacial Adhesion ◽  
Thermal Characterization ◽  
Mechanical And Thermal Properties ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Three Point Bending ◽  
Twin Screw ◽  
Thermal Stability Of

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.

3D Micromixer

2012 ◽  
Author(s):  
Bahador Farshchian ◽  
Junseo Choi ◽  
Sunggook Park
Keyword(s):  
Cover Plate ◽  
Bottom Surface ◽  
Mixing Efficiency ◽  
Molding Process ◽  
Specific Flow ◽  
Pdms Stamp ◽  
Fluorescein Dye ◽  
Solvent Bonding ◽  
Peeling Off

This paper presents the fabrication of a 3D microchannel whose sidewalls and bottom surface are patterned with ratchets using a modified 3D molding process. In the modified 3D molding process the surface of poly(methyl methacrylate) (PMMA) is first patterned using a brass mold having ratchet structures. Then PDMS prepolymer was spin coated over the surface of micropatterned PMMA and cured followed by the primary molding using a brass mold having a T-conjunction protrusion. After primary molding demolding was done by first demolding the brass mold and then peeling off PDMS stamp from PMMA substrate. By setting a 45° angle between direction of ratchets patterned on the surface of PMMA and the brass mold protrusion prior to primary molding 45° slanted ratchets were formed on the sidewall and bottom surface of microchannel using the modified 3D molding. The scanning electron microscope (SEM) micrographs show a successful integration of micropatterns inside the microchannel. Holes were drilled in the inlet and outlet area of the 3D channel before bonding. A solvent bonding technique was used for bonding of 3D channel to a plain cover plate. After bonding capillary tubes were inserted into the holes and glued to the chip using an epoxy glue. For characterization of mixing fluorescence intensity was quantified in the 3D microchannel as deionized water and fluorescein dye injected from different inlets of 3D micromixer were mixed along the 3D microchannel and mixing efficiency was calculated. The results were compared with the data obtained for similar microdevice whose surfaces were not patterned. The results demonstrate at a specific flow rate a faster mixing occurs in a microdevice whose sidewall and bottom surface are patterned with slanted 45° ratchets.

Effect of polycyclosilane microstructure on thermal properties

2021 ◽  
Author(s):  
Qifeng Jiang ◽  
Sydnee Wong ◽  
Rebekka S Klausen
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Thermal Characterization ◽  
Side Chains ◽  
Phase Properties

Thermal characterization of polysilanes has focused on the influence of organic side chains, whereas little is understood about the influence of silane backbone microstructure on thermal stability, phase properties, and...

Sign in / Sign up

Export Citation Format

Share Document