melt compounding
Recently Published Documents


TOTAL DOCUMENTS

405
(FIVE YEARS 87)

H-INDEX

42
(FIVE YEARS 8)

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Shuichi Tanoue ◽  
Hideyuki Uematsu

Abstract In this paper, we discussed the characteristics and properties of polypropylene (PP)/magnesium oxide (MgO) composites prepared by melt compounding. In addition, we also discussed the effect of adding vapor-grown carbon fiber (VGCF) to PP/MgO composite on the properties of the composites. The thermal conductivity of PP/MgO increased with MgO content. In the region of MgO content of more than 30 vol%, the thermal conductivity of PP/MgO with MgO-10 (particle size of 10 μm) is the largest by comparison of other PP/MgO with different MgO sizes. The thermal conductivity of PP/MgO became increased by adding VGCF in PP/MgO. According to the estimation of thermal conductivity using Bruggeman’s equation, no synergistic effect was observed by adding VGCF into the PP/MgO composite. The surface resistance of PP/MgO significantly decreased by adding VGCF at a content of more than 3 vol%. At VGCF content of 1 vol%, the surface resistance of the composite became large, and the value was more than 109 Ω/sq. In addition, the Non-Newtonian property of PP/MgO composite melt was enhanced by the addition of VGCF into the composite.


2022 ◽  
Vol 1048 ◽  
pp. 15-20
Author(s):  
Ruey Shan Chen ◽  
Sahrim Ahmad

In this study, liquid natural rubber (LNR) toughened polylactic acid (PLA) incorporated with magnetite (Fe3O4) nanocomposites were fabricated via melt-compounding in an internal mixer and followed by hot/cold pressing. The effects of ultrasonic treatment time (1-3 hours) and Fe3O4 (0.5-4.0 wt%) nanoparticles loading on tensile, morphology and thermal stability were investigated. Based on tensile testing results, the ultrasonication time of 1 hour was served as the most suitable treatment period to achieve the optimum distribution of Fe3O4 within PLA/LNR matrix. Among the investigated nanoparticles loading, 1 wt% Fe3O4 nanocomposite presented the highest tensile strength of 23.7 MPa, Young’s modulus of 1293.5 MPa and strain at break of 2.8%. SEM micrographs showed that the over-treated nanocomposites with 2-3 hours and over-high nanoparticles loading had resulted in the formation of clusters in the matrix. With increasing Fe3O4 loading, the decomposition of PLA/LNR nanocomposites was initiated earlier.


2021 ◽  
Vol 32 (3) ◽  
pp. 31-44
Author(s):  
Dylan Jia Yee Tong ◽  
◽  
Seong Chun Koay ◽  
Ming Yeng Chan ◽  
Kim Yeow Tshai ◽  
...  

Electric Discharge Machining (EDM) process uses electrodes made from graphite that wear out over time and are turned into scrap. In this research, EDM electrode scraps were recycled and turned into graphite powder (rGP). This rGP was used as a conductive filler to produce conductive polymer composite (CPC) material by combining it with polypropylene (PP) resin via melt compounding and compression moulding processes. The percolation threshold of this composite material changed when 30 wt% of rGP was added, whereby the insulative material changed became antistatic. The composite was able to achieve surface resistivity as low as 105 ohm/sq. However, the addition of higher rGP content deteriorated the tensile properties of composite, whereby the tensile strength of composite significantly decreased as compared to neat PP. The results also showed that the tensile modulus of this composite became higher, and the material became more brittle as compared to neat PP. However, the PP/rGP composite with 50 wt% filler content reduced the tensile modulus due to plasticising effect caused by the agglomeration of rGP. The addition of high filler content on PP/rGP composite also caused an increase in processing torque. This was due to the restriction of rGP particles to the melt flow of molten PP. The morphological analysis found that the PP/rGP composites with higher amounts of filler content were highly agglomerated and formed conductivity paths within the PP matrix. The increase of rGP content highly improved the thermal stability of composite. The findings of this study show that the rGP has the potential to be used as a conductive filler for producing conductive composite material.


2021 ◽  
Vol 36 (5) ◽  
pp. 545-556
Author(s):  
A. Hamza ◽  
R. K. Arya ◽  
A. D. Palsodkar ◽  
G. R. Bhadu ◽  
S. J. A. Rizvi

Abstract Isotactic polypropylene (iPP) was nucleated in-situ with calcium pimelate during melt compounding. Calcium pimelate is a highly effective β-nucleator for isotactic polypropylene (iPP). The β-nucleated iPP was characterized by wide angle x-ray diffraction (WAXD) and differential scanning calorimetry (DSC) for its crystallinity and crystal structure. In addition, the injection-molded samples were tested for thermo-mechanical properties. It is found that very low quantity (< 0.1 wt. %) of β-nucleator is required to produce sufficiently high β-crystal fraction (Kβ) in isotactic polypropylene. β-nucleated iPP shows increment of 11 to 14 °C in its heat deflection temperature (HDT). It was also observed that slow cooling rate of β-nucleated iPP promotes the formation of β-crystals and that tensile stretching leads to complete transformation of β crystals into a-crystals at room temperature. It was also revealed that the presence of maleic anhydride grafted polypropylene (PP-g-MA), a well-known coupling agent (or compatibilizer), may reduce the (Kβ) value to a marginal extent. It was also observed that the thermo-mechanical properties were not much affected by the presence of PP-g-MA. Therefore, calcium pimelate may be used as β-nucleator in case of neat as well as reinforced polypropylene containing maleic anhydride as coupling agent.


Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3513
Author(s):  
Xiaodong Jin ◽  
Suping Cui ◽  
Shibing Sun ◽  
Jun Sun ◽  
Sheng Zhang

In this work, a novel intumescent flame retardant (IFR) system was fabricated by the introduction of chitin as a green charring agent, ammonium polyphosphate (APP) as the acid source, and melamine (MEL) as the gas source. The obtained chitin-based IFR was then incorporated into a polylactic acid (PLA) matrix using melt compounding. The fire resistance of PLA/chitin composites was investigated via the limiting oxygen index (LOI), UL-94 vertical burning, and cone calorimeter (CONE) tests. The results demonstrated that the combination of 10%APP, 5%chitin and 5%MEL could result in a 26.0% LOI, a V-0 rating after UL and a 51.2% reduction in the peak heat release rate during the CONE test. Based on the mechanism analysis from both the morphology and the chemical structure of the char, it was suggested that chitin was a promising candidate as a charring agent for chitin reacted with APP and MEL with the formation of an intumescent layer on the surface.


Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5154
Author(s):  
Marius Murariu ◽  
Armando Galluzzi ◽  
Yoann Paint ◽  
Oltea Murariu ◽  
Jean-Marie Raquez ◽  
...  

In the category of biopolymers, polylactide or polylactic acid (PLA) is one of the most promising candidates considered for future developments, as it is not only biodegradable under industrial composting conditions, but it is produced from renewable natural resources. The modification of PLA through the addition of nanofillers is considered as a modern approach to improve its main characteristic features (mechanical, thermal, barrier, etc.) and to obtain specific end-use properties. Iron oxide nanoparticles (NPs) of low dimension (10–20 nm) such as magnetite (Fe3O4), exhibit strong magnetization in magnetic field, are biocompatible and show low toxicity, and can be considered in the production of polymer nanocomposites requiring superparamagnetic properties. Accordingly, PLA was mixed by melt-compounding with 4–16 wt.% magnetite NPs. Surface treatment of NPs with a reactive polymethylhydrogensiloxane (MHX) was investigated to render the nanofiller water repellent, less sensitive to moisture and to reduce the catalytic effects at high temperature of iron (from magnetite) on PLA macromolecular chains. The characterization of nanocomposites was focused on the differences of the rheology and morphology, modification, and improvements in the thermal properties using surface treated NPs, while the superparamagnetic behavior was confirmed by VSM (vibrating sample magnetometer) measurements. The PLA−magnetite nanocomposites had strong magnetization properties at low magnetic field (values close to 70% of Mmax at H = 0.2 T), while the maximum magnetic signal (Mmax) was mainly determined by the loading of the nanofiller, without any significant differences linked to the surface treatment of MNPs. These bionanocomposites showing superparamagnetic properties, close to zero magnetic remanence, and coercivity, can be further produced at a larger scale by melt-compounding and can be designed for special end-use applications, going from biomedical to technical areas.


2021 ◽  
Vol 41 (9) ◽  
pp. 827-834
Author(s):  
Xin Guo ◽  
Le Kang ◽  
Lishui Sun ◽  
Li Liu ◽  
Guangye Liu

Abstract Nanocomposites of single-wall carbon nanotubes in isobutylene isoprene rubber (IIR/SWCNTs) were successfully prepared by a simple and green wet process. The traditional melt mixing process and organic solvent dissolution suffered from unable to effectively disperse the SWCNTs of tangled structure, and degradation of polymer molecules, respectively. Our process very well avoided these two problems. The SWCNTs aqueous solutions emulsified by polyoxyethylene octyl phenol ether (OP-10) were firstly mixed and compounded with IIR rubber at a relatively high temperature, followed by the second step of melt compounding process with the addition of cross-linking agent and accelerators. The SWCNTs were dispersed uniformly, and a fine network was constructed in the matrix of the obtained IIR/SWCNTs nanocomposite with a low percolation threshold. With the concentration of SWCNTs as low as 2 phr, the IIR/SWCNTs nanocomposite received an electrical conductivity of 10−6∼10−3 S/cm, and a 71% improvement of tensile strength. By varying the loadings of SWCNTs in a certain range, the tensile strength, electrical conductivity, and dielectric property were found tunable. Besides, the nanocomposites also presented strain responsive specific resistance, excellent elongation (600–740%), and better heat resistance.


Author(s):  
Rajesh Kumar Sahoo

Polypropylene/silver nanoparticles nanocomposite films were prepared by melt compounding method by using polypropylene pallets and silver nanoparticles powder. The physical properties of the virgin polypropylene film and nanocomposite films were evaluated by mechanical testing. The effect of various silver nanoparticles content in the polymer nanocomposites with respect to its antimicrobial efficacy against the Gram positive bacteria Escherichia coli and Gram positive bacteria Staphylococcus aureus were studied. Nanocomposite film containing higher percentage of silver nanoparticles loading showed 99.9 % efficacy against the bacteria as compared to virgin polypropylene film.


2021 ◽  
pp. 096739112110252
Author(s):  
O Meziane ◽  
AR Bensedira ◽  
M Guessoum

The aim is to study the reactive compatibilization of two immiscible thermoplastic polyesters, namely polycarbonate (PC) and poly (ethylene terephthalate) (PET), by transesterification reactions through melt compounding. For this, a catalyst, which is hydrated samarium acetylacetonate (Sm(acac)3), is incorporated with concentrations of 0.10, 0.15 and 0.20 phr into the 70PC/30PET mixture. The characterization of the PC/PET blends by differential scanning calorimetry (DSC) revealed that, the transesterification reactions in the absence of catalyst are undetectable or practically impossible; however, by increasing the catalyst concentration, significant variations are noticed on the thermal properties. These modifications, due to the interfacial reactions between the two phases of the system, were also evidenced by variations in morphological properties observed after the study of atomic force microscopy (AFM).


2021 ◽  
Vol 5 (2) ◽  
pp. 11-17
Author(s):  
Anrong Huang ◽  
Jing Sun ◽  
Shanshan Luo ◽  
Heng Luo

Nylon 1212/organic montmorillonite (OMMT) nanocomposites were prepared using the melt compounding method. The morphology and dynamical mechanical properties of the nanocomposites were investigated using transmission electron microscope (TEM) and dynamic mechanical analysis (DMA). The storage modulus of nylon 1212/OMMT nanocomposites was increased with increasing OMMT. The flame retardant properties were characterized by cone calorimetry, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The flame retardant properties were characterized using cone calorimetry, whereby nylon 1212/OMMT nanocomposites were improved compared with pure nylon 1212 because of the carbonaceous-silicate granular materials which were formed during combustion, thus proposing the flame retardant mechanism.


Sign in / Sign up

Export Citation Format

Share Document