scholarly journals Injection-Molded Parts of Partially Biobased Polyamide 610 and Biobased Halloysite Nanotubes

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1503 ◽  
Author(s):  
David Marset ◽  
Celia Dolza ◽  
Teodomiro Boronat ◽  
Nestor Montanes ◽  
Rafael Balart ◽  
...  

This works focuses on the development of environmentally friendly composites with a partially biobased polyamide 610 (PA610), containing 63% biobased content, and a natural inorganic filler at the nanoscale, namely, halloysite nanotubes (HNTs). PA610 composites containing 10, 20, and 30 wt% HNTs were obtained by melt extrusion in a twin screw co-rotating extruder. The resulting composites were injection-molded for further characterization. The obtained materials were characterized to obtain reliable data about their mechanical, thermal, and morphological properties. The effect of the HNTs wt% on these properties was evaluated. From a mechanical standpoint, the addition of 30 wt% HNTs gave an increase in tensile modulus of twice the initial value, thus verifying how this type of natural load provides increased stiffness on injection molded parts. The materials prepared with HNTs slightly improved the thermal stability, while a noticeable improvement on thermomechanical resistance over a wide temperature range was observed with increasing HNTs content. The obtained results indicate that high biobased content composites can be obtained with an engineering thermoplastic, i.e., PA610, and a natural inorganic nanotube-shaped filler, i.e., HNTs, with balanced mechanical properties and attractive behavior against high temperature.

2018 ◽  
Vol 38 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Suvendu Padhi ◽  
P. Ganga Raju Achary ◽  
Nimai C. Nayak

AbstractHalloysite nanotubes (HNTs) were modified by γ-methacryloxypropyltrimethoxysilane (γ-MPS) as it interacts with the aluminol and silanol groups of HNTs present at the edges and surfaces of HNTs. The polymer composites were prepared by means of the solution casting method with ethylene-vinyl acetate (EVA) copolymer having 45% vinyl acetate (VA) content with different weight percent of modified HNTs (m-HNTs). The modification of the HNTs by γ-MPS increases the interfacial and inter-tubular interactions and the degree of dispersion of the HNTs within the EVA matrix which manifest from increase in crosslinking density. The mechanical properties such as tensile strength, tensile modulus and tear strength of nanocomposites were found to increase because of m-HNT. The glass transition temperature (Tg) and the crystalline percentage decreases for EVA/m-HNT nanocomposites were due to the strong interaction between EVA matrix and filler. Also, the EVA/m-HNT nanocomposites exhibited better thermal stability due to the strong inter-tubular interaction.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3050
Author(s):  
David Marset ◽  
Celia Dolza ◽  
Eduardo Fages ◽  
Eloi Gonga ◽  
Oscar Gutiérrez ◽  
...  

The main objective of the work reported here was the analysis and evaluation of halloysite nanotubes (HNTs) as natural flame retardancy filler in partially biobased polyamide 610 (PA610), with 63% of carbon from natural sources. HNTs are naturally occurring clays with a nanotube-like shape. PA610 compounds containing 10%, 20%, and 30% HNT were obtained in a twin-screw co-rotating extruder. The resulting blends were injection molded to create standard samples for fire testing. The incorporation of the HNTs in the PA610 matrix leads to a reduction both in the optical density and a significant reduction in the number of toxic gases emitted during combustion. This improvement in fire properties is relevant in applications where fire safety is required. With regard to calorimetric cone results, the incorporation of 30% HNTs achieved a significant reduction in terms of the peak values obtained of the heat released rate (HRR), changing from 743 kW/m2 to about 580 kW/m2 and directly modifying the shape of the characteristic curve. This improvement in the heat released has produced a delay in the mass transfer of the volatile decomposition products, which are entrapped inside the HNTs’ lumen, making it difficult for the sample to burn. However, in relation to the ignition time of the samples (TTI), the incorporation of HNTs reduces the ignition start time about 20 s. The results indicate that it is possible to obtain polymer formulations with a high renewable content such as PA610, and a natural occurring inorganic filler in the form of a nanotube, i.e., HNTs, with good flame retardancy properties in terms of toxicity, optical density and UL94 test.


2018 ◽  
Vol 248 ◽  
pp. 01006
Author(s):  
Yovial Mahyoedin ◽  
Jaafar Sahari ◽  
Andanastuti Mukhtar ◽  
Norhamidi Mohammad ◽  
Iqbal

The investigations in this study focused on the characteristic of feedstock in an effort to understand the mechanism of injection molded in composite material. A composite, which has 75% wt. filler, consist of graphite (G), carbon black (CB) and polypropylene copolymer (PP). Twin-screw co-rotating extruder used for mixing materials. The conductivity of the molded parts measured using a four-point probe test procedure. The results showed that the injection molding conducting composites, which aggregated into larger clusters, tended to disperse unevenly into the PP, resulting in fewer particle-particle contacts and, consequently, a lower-conductivity composite in some part of the molded.


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.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Harri Junaedi ◽  
Essam Albahkali ◽  
Muneer Baig ◽  
Abdulsattar Dawood ◽  
Abdulhakim Almajid

In this work, the ductile to brittle transition behavior of short carbon fiber (SCF)-reinforced polypropylene (PP) composite is studied. Initially, the SCF-reinforced PP composites with a varying composition of SCF in the range of 0–40 wt% loading were first melt-mixed in a twin-screw extruder and later injection-molded to produce the testing samples. The experimental results indicate that with an increase in SCF loading, an increase in the tensile modulus and strength was observed along with a rapid decrease in the values of strain at break. A sudden decrease in strain at break was observed in composites in the range of 10–15 wt% SCF. To further study the sudden decrease in strain at break, an investigation was performed on composites that contained 10–15 wt% of SCF loading, starting from 10 wt% with a 1% increment to 15 wt% of SCF. The results of this study show that a decrease in strain at break was not linear; on the contrary, it was accompanied by a ductile to brittle transition, which specifically occurred in the range of 12–13 wt% of SCF loading and then continued to decrease with an increase in SCF loading.


2013 ◽  
Vol 594-595 ◽  
pp. 715-719 ◽  
Author(s):  
S.T. Sam ◽  
P. Santhiya ◽  
S. Ragunathan ◽  
N.Z. Noriman ◽  
H. Ismail

The spear grass content on the tensile properties, morphology of low-density polyethylene (LDPE)/spear grass was investigated. The compatibilising effect of epoxidised natural rubber (ENR 50) LDPE and spear grass was mixed by using twin screw extruder with various spear grass contents. The tensile properties were tested by using an Universal Testing Machine (UTM). The tensile strength and elongation at the break point were significantly improved by the addition of ENR 50, as evidenced by morphological analysis using scanning electron microscopy (SEM). On the other hand, the tensile modulus increased with spear grass content up to 10% and decreased thereafter.Keywords: Epoxidised Natural rubber (ENR), Low Density Polyethylene (LDPE), Spear Grass, Tensile Properties


2017 ◽  
Vol 52 (5) ◽  
pp. 689-700 ◽  
Author(s):  
Gulyaz Al ◽  
Deniz Aydemir ◽  
Bulent Kaygin ◽  
Nadir Ayrilmis ◽  
Gokhan Gunduz

The aim of this study was to investigate the effects of cellulose nanofibrils and nanoclays on the mechanical, thermal, and morphological properties of polyhydroxybutyrate and polylactic acid bio-polymers. Polyhydroxybutyrate and polylactic acid as a polymer matrix and nanoclays and cellulose nanofibrils as reinforcing nano-fillers were used to prepare the biopolymer nanocomposites in twin screw extruder. Density, flexure strength and flexure modulus, tensile strength and tensile modulus, impact strength, thermal properties, and morphological characterization of the obtained biopolymer nanocomposites were determined. According to the obtained results, densities of the biopolymer nanocomposites were found to decrease with addition of the bio-fillers, and it was determined to be decreasing the density due to increasing the porosity in biopolymer nanocomposites. Although the increasing in the porosity of biopolymer nanocomposites was found in scanning electron microscope pictures, the mechanical properties of the biopolymer nanocomposites generally increased as compare with neat bio-polymers. Thermal analysis conducted with thermogravimetric-dynamic thermal analysis and differential scanning calorimeter showed that thermal stability of the biopolymer nanocomposites generally improved according to the neat bio-polymers.


2015 ◽  
Vol 76 (7) ◽  
Author(s):  
Tuan Noraihan Azila Tuan Rahim ◽  
Hazizan Md Akil ◽  
Abdul Manaf Abdullah ◽  
Dasmawati Mohamad ◽  
Zainul Ahmad Rajion

Fused filament fabrication is a filament based rapid prototyping process, which offers the possibility of new polymer material for invention of biomedical implant. This study represents an investigation on a preparation and characterization of new polyamide 12 reinforced with 20 wt% of zirconium dioxide and hydroxyapatite by desktop 3D printer in comparison with conventional manufacturing method, injection molding. Polyamide 12 composite was compounded, pelletized and filament-extruded prior to apply to a 3D printer. Sample prototypes from the new polyamide composite have been successfully made and tested. Mechanical (flexural and impact) and morphological properties were evaluated and compared. From the results, the printed polyamide composite exhibited lower mechanical properties than injection molded due to the formation of porosity, laminate weakness and low pressure during printing. Although the mechanical properties of printed parts were lower than molded parts, but the capability of 3D printer to fabricate any customized 3D object could lead to the bright future and great contribution in this area, while at the same time many improvements can be made for the future works.


2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2523
Author(s):  
Franciszek Pawlak ◽  
Miguel Aldas ◽  
Francisco Parres ◽  
Juan López-Martínez ◽  
Marina Patricia Arrieta

Poly(lactic acid) (PLA) was plasticized with maleinized linseed oil (MLO) and further reinforced with sheep wool fibers recovered from the dairy industry. The wool fibers were firstly functionalized with 1 and 2.5 phr of tris(2-methoxyethoxy)(vinyl) (TVS) silane coupling agent and were further used in 1, 5, and 10 phr to reinforce the PLA/MLO matrix. Then, the composite materials were processed by extrusion, followed by injection-molding processes. The mechanical, thermal, microstructural, and surface properties were assessed. While the addition of untreated wool fibers to the plasticized PLA/MLO matrix caused a general decrease in the mechanical properties, the TVS treatment was able to slightly compensate for such mechanical losses. Additionally, a shift in cold crystallization and a decrease in the degree of crystallization were observed due to the fiber silane modification. The microstructural analysis confirmed enhanced interaction between silane-modified fibers and the polymeric matrix. The inclusion of the fiber into the PLA/MLO matrix made the obtained material more hydrophobic, while the yellowish color of the material increased with the fiber content.


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