Effects of Fiber Mass Fraction and Alkali Concentration on Mechanical Properties of Biodegradable Composites

2010 ◽  
Vol 152-153 ◽  
pp. 1677-1682
Author(s):  
Zhi Yong Qin ◽  
Yi Qiang Wu ◽  
Xin Gong Li ◽  
Yan Qing

Biodegradable composites of polylactic acid reinforced with wood fiber are fabricated by using twin screw extruder followed by the injection molding machine. The effects of fiber mass fraction and alkali concentration on mechanical properties of biodegradable composites are investigated. The results show that the mechanical properties of biodegradable composites presented tendency which reduced first, elevated, and again reduced along with fiber mass fraction increased, after the alkali treatment, the mechanical properties of biodegradable composites have the tendency which increased first and then reduced, when the concentration of alkali solution is 8%, both the tensile strength and impact strength are best. The scanning electron microscope and Infrared Spectrum Analysis are also used for examination of biodegradable composites.

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2459-2465 ◽  
Author(s):  
R. J. T. LIN ◽  
D. BHATTACHARYYA ◽  
S. FAKIROV

The concept of microfibrillar composite (MFC) has been used to create a new type of polymer composites, in which the reinforcing microfibrils are loaded with carbon nanotubes (CNT). Polyamide 66 (PA66) has been melt blended with polypropylene in a twin screw extruder with and without CNT, and thereafter cold drawn to create a fibrillar state as well as to align the CNT in the PA66 microfibrils. The drawn bristles were compression moulded at 180°C to prepare MFC plates. The scanning electron microscope (SEM) observations indicate near perfect distribution of CNT in the reinforcing PA66 microfibrils. Although the fibrillated PA66 is able to improve the tensile stiffness and strength as expected from the MFC structure, the incorporation of CNT does not exhibit any further enhancing effect. It rather adversely affects the mechanical properties due to poor interface adhesion between the matrix and the reinforcing microfibrils with the presence of CNT, as demonstrated by SEM. However, the resulting highly aligned CNT within the MFC are expected to affect the physical and functional properties of these composites.


2022 ◽  
Author(s):  
A.M. Kuzmin

Abstract. The article discusses the possibility of obtaining biodegradable films based on polyolefins and beet pulp by the extrusion method. Biodegradable composites of two mixes with 15% and 25% beet pulp content have been obtained. Compounding was carried out on a twin-screw extruder, and then samples of biodegradable films were obtained by cast film extrusion. The influence of the vegetable filler particles’ orientation on the composites mechanical properties has been studied. It has been shown that composites mechanical properties significantly increase in the direction of polymer melt stretching.


2019 ◽  
Vol 805 ◽  
pp. 59-64
Author(s):  
Achmad Chafidz ◽  
Cholila Tamzysi ◽  
Lilis Kistriyani ◽  
Ratna Dewi Kusumaningtyas ◽  
Dhoni Hartanto

PP/clay nanocomposites samples of 1st and 2nd cycles (recycle) and different nanoclay loadings (i.e. 0, 5, 10, 15 wt%) samples were made by utilizing twin-screw extruder and injection molding machine. The samples were then characterized using a tensile test machine. The tensile tests results showed that modulus of elasticity and tensile strength of the nanocomposites samples for both 1st and 2nd cycles were all higher than the neat PP, and increased with increasing nanoclay loadings. The enhancements of modulus of elasticity (as compared to the neat PP) for 1st cycle of the nanocomposites were about 38.08%, 49.33%, and 78.65% for NC-5-I, NC-10-I, and NC-15-I, respectively. Whereas, for the 2nd cycle of the nanocomposites were about 44.33%, 59.59%, and 84.69% for NC-5-II, NC-10-II, and NC-15-I, respectively. This indicated that the incorporation of nanoclay in the PP matrix significantly increased mechanical properties, especially modulus of elasticity and tensile strength of the nanocomposites. Additionally, values of modulus of elasticity and tensile strength of 1st cycle and 2nd cycle of PP/clay nanocomposites were compared by plotting them in two graphs. The plots revealed that reprocessing of the nanocomposites did not significantly influence the mechanical properties of the nancomposites.


2013 ◽  
Vol 747 ◽  
pp. 351-354 ◽  
Author(s):  
Poonsub Threepopnatkul ◽  
Thanaphat Krachang ◽  
Wipawee Teerawattananon ◽  
Katawut Suriyaphaparkor ◽  
Chanin Kulsetthanchalee

This research is to study the effect of two different flame retardants i.e., bisphenol-A bis (diphenyl phosphate) (BDP) and 9, 10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) on the flammability and mechanical properties of the composites of modified natural pineapple leaf fiber (PALF) reinforced acrylonitrile butadiene styrene (ABS). A 10% by weight of such PALF was compounded with ABS using diisononyl phthalate 1% w/w as plasticizer at the different flame retardant concentration (10 and 20 wt%) in a co-rotating twin screw extruder. An injection molding machine was used to prepare the specimens. The effects of flame-retardants showed that the PALF/ABS composite containg DOPO showed superior performance in terms of flammabitily. Higher content of flame retardants led to increase LOI value. Moreover, the composites added DOPO produce enhanced mechanical properties such as youngs modulus and tensile strength.


2016 ◽  
Vol 840 ◽  
pp. 91-96 ◽  
Author(s):  
Bashree Abu Bakar ◽  
Mohamad Najmi Masri ◽  
Mohd Hazim Mohamad Amini ◽  
Mazlan Mohamed ◽  
Muhammad Azwadi Sulaiman ◽  
...  

Wood plastic composites (WPC) have been produced by compounding meranti wood flour (WF) with polypropylene (PP) copolymer using a twin-screw extruder. The meranti WF content was varied from 30 to 60 wt.%. The mechanical properties, i.e. tensile, flexural and impact of the composites were determined on injection-molded specimens. The tensile fractured surfaces were used to study the morphological properties of the composites. The result shows that the increment in WF content has given a significant improvement in modulus properties but at the expense of strength and toughness properties. A commercial maleic anhydride grafted polypropylene (MAPP) compatibilizer at 5 wt.% was incorporated into the PP40/WF60 formulation. The strength, stiffness and toughness properties were improved significantly in the presence of MAPP. The morphology of the composites was studied by scanning electron microscopy (SEM). The improvement of the fibre-matrix adhesion between the WF and PP matrix as revealed by SEM is believed to be one of the major reasons for the improved mechanical properties.


Author(s):  
Rasool Mohsenzadeh ◽  
Hojjat Majidi ◽  
Mohsen Soltanzadeh ◽  
Karim Shelesh-Nezhad

Nanocomposite gears and standard mechanical testing specimens based on polyoxymethylene containing different fractions (0, 3, 6, and 9 wt%) of nanosized precipitated calcium carbonate particles were produced by using twin-screw extruder and injection molding machine. The wear and temperature of gears teeth were measured by a gear test rig. The morphologies of fractured gears teeth were analyzed by using scanning electron microscopy. Results of experiments indicate that the incorporation of CaCO3 nanoparticles into polyoxymethylene increases the flexural and heat resistance and reduces the magnitudes of wear and temperature of gears noticeably. The maximum flexural resistance is achieved by employing 3 wt% of CaCO3 nanoparticles. Gears containing 3 wt% of CaCO3 nanoparticles present the lowest wear rate, which is 61% smaller than that of neat polyoxymethylene gear. The life time (durability till failure) of nanocomposite gear was twofold as compared to neat polyoxymethylene gear. The nanocomposite gear showed abrasive-wear and brittle-fracture, yet the neat polyoxymethylene gear demonstrated prevailing cohesive wear and ductile failure.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1058
Author(s):  
Hikaru Okubo ◽  
Haruka Kaneyasu ◽  
Tetsuya Kimura ◽  
Patchiya Phanthong ◽  
Shigeru Yao

Each year, increasing amounts of plastic waste are generated, causing environmental pollution and resource loss. Recycling is a solution, but recycled plastics often have inferior mechanical properties to virgin plastics. However, studies have shown that holding polymers in the melt state before extrusion can restore the mechanical properties; thus, we propose a twin-screw extruder with a molten resin reservoir (MSR), a cavity between the screw zone and twin-screw extruder discharge, which retains molten polymer after mixing in the twin-screw zone, thus influencing the polymer properties. Re-extruded recycled polyethylene (RPE) pellets were produced, and the tensile properties and microstructure of virgin polyethylene (PE), unextruded RPE, and re-extruded RPE moldings prepared with and without the MSR were evaluated. Crucially, the elongation at break of the MSR-extruded RPE molding was seven times higher than that of the original RPE molding, and the Young’s modulus of the MSR-extruded RPE molding was comparable to that of the virgin PE molding. Both the MSR-extruded RPE and virgin PE moldings contained similar striped lamellae. Thus, MSR re-extrusion improved the mechanical performance of recycled polymers by optimizing the microstructure. The use of MSRs will facilitate the reuse of waste plastics as value-added materials having a wide range of industrial applications.


1998 ◽  
Vol 4 (S2) ◽  
pp. 838-839
Author(s):  
A. Egan ◽  
S. Shaler

Single fiber fracture is important in understanding the fundamental failure mechanisms in wood/polymer composite products such as medium density fiberboard (MDF). The mechanical properties and fracture behavior of individual wood fibers has only recently been observable using a combination of environmental scanning electron microscopy (ESEM), laser scanning confocal microscopy and digital image correlation (DIC). Previous work has shown that specific areas on the fiber such as microcompressions and pits acted as crack nucelators and induce a brash fracture across the surface of the fiber. Given the development of these procedures it is now possible to observe and measure the mechanical properties and fracture characteristics of the wood fiber/ polymer composite fibers.Individual black spruce wood fibers were coated with diphenylmethane 4-4'diisocyanate resin containing Hostasol Red GG. The addition of the Hostasol Red flurochrome provided the option of quantifying resin coverage by fluorescence microscopy.


2014 ◽  
Vol 496-500 ◽  
pp. 317-321
Author(s):  
Shou Hai Wang ◽  
Jun Gao ◽  
Gu Ren Fei ◽  
Ping Zhang ◽  
Jun Huang ◽  
...  

Acrylonitrile-butadiene-styrene (ABS) / polymethyl methacrylate (PMMA) with the addition of maleic anhydride grafted polystyrene (KT-5) and polyolefin elastomer (POE) were melt processed in a co-rotating twin-screw extruder. The effect of KT-5 and POE content on the mechanical properties of ABS/PMMA was investigated. Experiment results indicate that KT-5 can improve the tensile strength and the composites are toughened effectively as the addition of POE. According to Orthogonal tests, it demonstrates that POE ha a greater effect on the blends than KT-5, and there exist no obvious interactivity between the two components.


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