scholarly journals THERMAL BEHAVIOR IMPROVEMENT OF BIODEGRADABLE FIBER POLYMER COMPOSITES POLYLACTIC ACID (PLA)/COIR USING ACEH’S BENTONITE

2021 ◽  
Vol 9 (11) ◽  
pp. 97-108
Author(s):  
Ridwan ◽  
Teuku Rihayat ◽  
Adi Saputra Ismy ◽  
Nurhanifa Aidy ◽  
Awanis Ilmi

Research has been conducted on the manufacture of PLA Coir Bentonite composites. This study aims to examine the effect of PLA on mechanical strength with the addition of coir and bentonite fillers from North Aceh and Central Aceh. The sample formulations used were single polymer PLA/Coir and PLA/Coir with variations of filler Bentonite Aceh Utara and Aceh Tengah with 2, 4, 6 and 8% respectively. The combination of PCa samples showed the highest bacterial colony growth rate, which was more than 100 colonies/gram during the 1 week testing period. In the PBATd filler mixture sample, the maximum bacterial test value was 65 colonies/gram and the minimum value contained in the PBAUa sample was 105 colonies/gram. The best tensile strength was obtained in the PBATc sample, namely 65 MPa. PBATd samples began to degrade at 370.15oC compared to PCa samples degraded at 280.21oC. While the PBAUa sample began to degrade at a temperature of 282.11oC. The surface structure of the PCa sample is more homogeneous because there is no bentonite filler mixture, but it is brittle and crumbles easily. For the PBATd sample, the surface structure is smoother and more homogeneous compared to the PBAUa sample.

2021 ◽  
Vol 11 (15) ◽  
pp. 6946
Author(s):  
Bartłomiej Podsiadły ◽  
Andrzej Skalski ◽  
Wiktor Rozpiórski ◽  
Marcin Słoma

In this paper, we are focusing on comparing results obtained for polymer elements manufactured with injection molding and additive manufacturing techniques. The analysis was performed for fused deposition modeling (FDM) and single screw injection molding with regards to the standards used in thermoplastics processing technology. We argue that the cross-section structure of the sample obtained via FDM is the key factor in the fabrication of high-strength components and that the dimensions of the samples have a strong influence on the mechanical properties. Large cross-section samples, 4 × 10 mm2, with three perimeter layers and 50% infill, have lower mechanical strength than injection molded reference samples—less than 60% of the strength. However, if we reduce the cross-section dimensions down to 2 × 4 mm2, the samples will be more durable, reaching up to 110% of the tensile strength observed for the injection molded samples. In the case of large cross-section samples, strength increases with the number of contour layers, leading to an increase of up to 97% of the tensile strength value for 11 perimeter layer samples. The mechanical strength of the printed components can also be improved by using lower values of the thickness of the deposited layers.


1997 ◽  
Vol 12 (4) ◽  
pp. 1091-1101 ◽  
Author(s):  
Seunggu Kang ◽  
Hongy Lin ◽  
Delbert E. Day ◽  
James O. Stoffer

The dependence of the optical and mechanical properties of optically transparent polymethyl methacrylate (PMMA) composites on the annealing temperature of BK10 glass fibers was investigated. Annealing was used to modify the refractive index (R.I.) of the glass fiber so that it would more closely match that of PMMA. Annealing increased the refractive index of the fibers and narrowed the distribution of refractive index of the fibers, but lowered their mechanical strength so the mechanical properties of composites reinforced with annealed fibers were not as good as for composites containing as-pulled (chilled) glass fibers. The refractive index of as-pulled 17.1 μm diameter fibers (R.I. = 1.4907) increased to 1.4918 and 1.4948 after annealing at 350 °C to 500 °C for 1 h or 0.5 h, respectively. The refractive index of glass fibers annealed at 400 °C/1 h best matched that of PMMA at 589.3 nm and 25 °C, so the composite reinforced with those fibers had the highest optical transmission. Because annealed glass fibers had a more uniform refractive index than unannealed fibers, the composites made with annealed fibers had a higher optical transmission. The mechanical strength of annealed fiber/PMMA composites decreased as the fiber annealing temperature increased. A composite containing fibers annealed at 450 °C/1 h had a tensile strength 26% lower than that of a composite made with as-pulled fibers, but 73% higher than that for unreinforced PMMA. This decrease was avoided by treating annealed fibers with HF. Composites made with annealed and HF (10 vol. %)-treated (for 30 s) glass fibers had a tensile strength (∼200 MPa) equivalent to that of the composites made with as-pulled fibers. However, as the treatment time in HF increased, the tensile strength of the composites decreased because of a significant reduction in diameter of the glass fiber which reduced the volume percent fiber in the composite.


2015 ◽  
Vol 749 ◽  
pp. 278-281
Author(s):  
Jia Horng Lin ◽  
Jing Chzi Hsieh ◽  
Jin Mao Chen ◽  
Wen Hao Hsing ◽  
Hsueh Jen Tan ◽  
...  

Geotextiles are made of polymers, and their conjunction with different processes and materials can provide geotextiles with desirable characteristics and functions, such as filtration, separation, and drainage, and thereby meets the environmental requirements. Chemical resistant and mechanical strong polymers, including polyester (PET) and polypropylene (PP), are thus used to prolong the service life of the products made by such materials. This study proposes highly air permeable geotextiles that are made with different thicknesses and various needle punching speeds, and the influences of these two variables over the pore structure and mechanical properties are then examined. PET fibers, PP fibers, and recycled Kevlar fibers are blended, followed by being needle punched with differing spaces and speeds to form geotextiles with various thicknesses and porosities. The textiles are then evaluated for their mechanical strength and porosity. The test results show that a thickness of 4.5 cm and 1.5 cm demonstrate an influence on the tensile strength of the geotextiles, which is ascribed to the webs that are incompletely needle punched. However, the excessive needle punching speed corresponding to a thickness of 0.2 cm results in a decrease in tensile strength, but there is also an increase in the porosity of the geotextiles.


2013 ◽  
Vol 592-593 ◽  
pp. 647-650 ◽  
Author(s):  
Małgorzata Lenart

Cement – polymer composites are nowadays widely used in repair systems not only in case of concrete or reinforced concrete constructions but also in masonry. Polymers addition for example already at 5% m.c. modifies the structure of the cement – polymer composite in a way that many of the mechanical properties such as flexural strength, tensile strength or adhesion to substrates are improved. The paper presents the results of tests such as flexural, compressive or adhesion strength to ceramic substrate of hardened cement mortars with different composition, as well as selected cement mortars modified by two polymers: polyvinyl alcohol and styrene – butadiene polymer dosed at 5 % m.c. Four types of cement mortars modified by lime (component used in historical constructions as well as in contemporary masonry mortars) are also examined for comparison.


2005 ◽  
Vol 222 (1) ◽  
pp. 187-194 ◽  
Author(s):  
Jean Fran�ois Feller ◽  
Patrick Glouannec ◽  
Patrick Salagnac ◽  
Guillaume Droval ◽  
Philippe Chauvelon

2022 ◽  
Vol 327 ◽  
pp. 82-97
Author(s):  
He Qin ◽  
Guang Yu Yang ◽  
Shi Feng Luo ◽  
Tong Bai ◽  
Wan Qi Jie

Microstructures and mechanical properties of directionally solidified Mg-xGd (5.21, 7.96 and 9.58 wt.%) alloys were investigated at a wide range of growth rates (V = 10-200 μm/s) under the constant temperature gradient (G = 30 K/mm). The results showed that when the growth rate was 10 μm/s, different interface morphologies were observed in three tested alloys: cellular morphology for Mg-5.21Gd alloy, a mixed morphology of cellular structure and dendritic structure for Mg-7.96Gd alloy and dendrite morphology for Mg-9.58Gd alloy, respectively. Upon further increasing the growth rate, only dendrite morphology was exhibited in all experimental alloys. The microstructural parameters (λ1, λ2) decreased with increasing the growth rate for all the experimental alloy, and the measured λ1 and λ2 values were in good agreement with Trivedi model and Kattamis-Flemings model, respectively. Vickers hardness and the ultimate tensile strength increased with the increase of the growth rate and Gd content, while the elongation decreased gradually. Furthermore, the relationships between the hardness, ultimate tensile strength, the growth rate and the microstructural parameters were discussed and compared with the previous experimental results.


2001 ◽  
Vol 263 (1) ◽  
pp. 1-23 ◽  
Author(s):  
Pernille Hermansen ◽  
Poul S Larsen ◽  
Hans Ulrik Riisgård

2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.


2017 ◽  
Vol 758 ◽  
pp. 56-60 ◽  
Author(s):  
Arief Cahyanto ◽  
Atina Ghina Imaniyyah ◽  
Myrna Nurlatifah Zakaria ◽  
Zulia Hasratiningsih

Mechanical strength is one of the key factors for clinical application of injectable carbonate apatite (CO3Ap) cement. Incorporation of polymeric additives into the mixing liquid of injectable bone cement has been known to improve cement injectability. The aim of this study is to determine whether incorporation of sodium carboxymethyl cellulose (Na CMC) into the mixing liquid would affect the diametral tensile strength (DTS) of injectable CO3Ap cement. In the present study, Na CMC, a polymeric additive and a cellulose derivative, was used to promote the injectability of CO3Ap cement. Three groups of CO3Ap cement samples consist of CaCO3 and CaHPO4 powder in each group were mixed with 0.5 %, 1%, and 2% Na CMC solution incorporated to 0.2 mol/L Na2HPO4 solution. As a control, powder mixed with 0.2 mol/L Na2HPO4 solution was used. Samples were kept in an incubator (37°C, 100% relative humidity, 24 hours). The mechanical strength properties were evaluated by diametral tensile strength (DTS). The average DTS of samples containing 0.5%, 1%, and 2% Na CMC were 3.19 MPa, 3.57 MPa, and 3.06 MPa, respectively. While the average DTS of the control group was 3.29 MPa. The groups containing Na CMC in all concentrations showed no statistical difference (p>0.05) on DTS compared to the control group. The injectability improved as the concentration of Na CMC increased. In conclusion, revealed that Na CMC does not affect the mechanical strength of CO3Ap cement. Therefore, it may be considered as an effective material to promote cement injectability. Further study of additives that can be used to promote the injectability of CO3Ap cement and enhance the mechanical strength awaits based on this initial finding.


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