Nylon-6 Composites Research Articles

High Electric Conductive PMMA Composites without Impact Value Decay by Dispersion of Copper Powder

Copper powder dispersed poly-methyl methacrylic acid (acrylic resin, PMMA) composites (PMMA-Cu) were prepared by the solution cast method. The Cu addition at the critical volume fraction (15:0 � 1:0 vol%Cu) drastically enhanced the electric conductivity from the insulator (10 � 14 Sm � 1 ) to the electric conductor (10 5 Sm � 1 ). The electric conductivity can be obtained by controlling the volume fraction of copper powders in PMMA polymers, as dilatation. The addition of 10 vol%Cu slightly enhanced the impact value of PMMA, whereas the remarkable decrease in the Charpy impact value was found at 25 � 5 vol%Cu. The high conductive PMMA-Cu composites (from 15 to 20 vol%Cu) with high impact value (5:5 � 0:5 kJm � 2 ), which was higher than that of dispersed nylon6 composites (2 kJm � 2 ) utilized for practical exteriors, were obtained without impact value decay by addition of small amount of copper powders. [doi:10.2320/matertrans.M2010120]

Impact Value of High Electric Conductive ABS Composites with Copper Powder Dispersion Prepared by Solution-Cast Method

Copper powder dispersed acrylonitrile butadiene styrene (ABS) composites were prepared by the solution cast method. Although the addition of Cu greatly enhanced the electric conductivity at the critical volume fraction (19:0þ=� 1:0 vol%Cu) from the insulator to the electric conductor, the decrease in the Charpy impact value was gradual. Since the impact value of the ABS polymer prepared by the solution cast method was 1.75 times larger than that before treatment, it is clear that the solution casting improved the impact value. When the volume fraction of Cu powders of high electric conductive ABS composites was from 20 to 30 vol%Cu, the impact value was 7 kJm � 2 . The moderated impact value was not only 44% of that of pure ABS polymer before solution casting, but was also higher than that of dispersed nylon6 composites (2 kJm � 2 ) utilizeed for practical exteriors. [doi:10.2320/matertrans.M2009171]

Preparation and Properties of Nano-Hydroxyapatite Modified Nylon Composites

To enhance the mechanical property and the bioactivity of composites, nano-hydroxyapatite (n-HA) modified monomer casting nylon-6 (n-HA/N) composites were prepared by in situ polymerization. During the synthesis of n-HA/N composite, the n-HA and caprolactam were mixed, melt and placed in the field of ultrasonic radiation. The differences between composite with ultrasonic and without ultrasonic were investigated. The tensile strength and the viscosity average molecular weight of the nylon matrix were measured. The results show that the molecular weight of the nylon matrix decreased firstly and it had the lowest value when the content of nano-hydroxyapatite was 1.6 wt.%. After that the molecular weight increased and then it began to decrease when it reached the highest value. But the tensile strength of the n-HA/N composite were improved. The ultrasonic dispersion made the n-HA more evenly dispersed in the nylon and increased the mechanical properties of the n-HA/N composites significantly. The bioactivity and moisture absorption of n-HA/N composites in simulated body fluid (SBF) were examined and compared to pure nylon. What's more, Fourier transform infrared spectrometer was used to characterize the structure of the materials formed on the surface of the composite. The results showed that moisture absorption of the n-HA/N composites was lower than that of the pure nylon. After composites impregnated 16 days in SBF, a layer of carbon hydroxyapatite (CHA) with weak crystalline was formed on the surface of sample. This phenomenon showed that the n-HA/N composites have good bioactivity.

Overweight of Nylon6 Composites Dispersed with Aluminum Powders by Dipping in Hot Salt Solution (3 mass%NaCl in Distilled Water)

The influence of dipping in hot salt solution on water absorption in nylon6 composites with dispersed aluminum powders was investigated. Dipping in hot salt solution (3 mass%NaCl in distilled water) for 105 s at 373 K increased the overweight of composite samples, whereas the addition of aluminum with dispersed powders (A1-addition) from zero to 40 vol%Al decreased the overweigh of the sample. Based on the experiment results and kinetic analysis, aluminum powder dispersion in nylon6 decreased the saturated overweigh of composites at infinite time. Both hot salt dipping and Al addition increased the reaction index (n). The Al addition apparently increased the n value of composites with less than 20 vol%Al in salt solution, as well as with less than 30 vol%Al in distilled water. The A1 addition apparently increased the kinetic constant (k) at less than 20 vol%Al in hot salt solution. However, the Al addition decreased the k value of composites at more than 30 vol%Al in hot salt dipping, as same as that of the composites dipped in hot distilled water. Compared with dipping in distilled water, dipping in hot salt solution apparently decreased the saturated overweigh and remarkably increased both n and k values of nylon6 composites with 10 and 20 vol%Al. Since Electron Probe Micro Analyzer (EPMA) analysis could not clearly detect sodium (Na) in the nylon6 matrix, the reaction rate of nylon6 composites dipped in hot salt solution was probably dominated by an interface control process.

An Experimental Study of the Water-Assisted Injection Molding of PA-6 Composites

This report was carried out to study experimentally the water-assisted injection molding process of glass fiber-reinforced polyamide-6 (Nylon-6) composites. Experiments were carried out on an 80 ton injection molding machine equipped with a lab scale water injection system, which included a water pump, a water injection pin, a pressure accumulator, a water tank equipped with a temperature regulator, and a control circuit. The materials used were Nylon and 30% glass fiber-filled Nylon composites. A spiral mold cavity was used to mold the composites. After molding, the lengths of water penetration in molded parts were measured. The effects of different processing parameters on the lengths of water penetration were determined: melt temperature, mold temperature, melt-filling speed, short-shot size, water pressure, water temperature, water hold, and water injection delay time. Mechanical property tests were performed on the water-assisted injection molded parts. X-ray diffraction was also employed to identify the structural parameters of the materials. In addition, the in-mold temperature distribution of the polymeric materials during the cooling process was measured. Irregular water penetration in molded parts was observed, and water temperature was found to affect the crystallinity distribution of molded parts. Nevertheless, its effects on the tensile properties of molded materials were relatively limited.

Morphology and Mechanical Properties of Multiwalled Carbon Nanotubes Reinforced Nylon-6 Composites. Volume 37, Number 19, September 21, 2004, pp 7214−7222.

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionMorphology and Mechanical Properties of Multiwalled Carbon Nanotubes Reinforced Nylon-6 Composites. Volume 37, Number 19, September 21, 2004, pp 7214−7222.Tianxi Liu, In Yee Phang, Lu Shen, Shue Yin Chow, and Wei-De ZhangCite this: Macromolecules 2007, 40, 24, 8812Publication Date (Web):October 25, 2007Publication History Published online25 October 2007Published inissue 1 November 2007https://doi.org/10.1021/ma7022843Copyright © 2007 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views606Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (4 KB) Get e-Alerts Get e-Alerts

Preparation and Characterisation of Antistatic Nylon-6 Filled with ZnO Whiskers

Antistatic composites of nylon-6 filled with ZnO whiskers (ZnOw), the surface of which was treated with a coupling agent, were prepared by melting-blend. Electrical, mechanical and rheological properties of the composites were determined and the effect of ZnOw loading level on these properties was determined. The structure, morphology, thermal properties, and crystallisation behaviour were examined in detail by FT-IR, SEM, TGA, WAXD, DSC etc. The results showed that the ZnOw were well dispersed in the nylon-6 matrix and they interacted well with the nylon-6 matrix. The crystallinity, melt temperature, tensile strength and hardness of the composites decreased gradually with increasing ZnOw content, but the antistatic performance, processing properties and thermal stability improved.

Influence of particle size and particle size distribution on MICA filled nylon 6 composite

Particulate reinforced thermoplastic composites are designed to improve the properties and to lower the overall cost of engineering plastics. In this study the effects of particle size and particle size distribution on the properties of mica filled nylon-6 was investigated. Composites of nylon-6 with varying concentrations (viz. 5 to 40 wt%) of mica were prepared by twin screw extrusion. The composite showed improved mechanical, thermal as well dielectric properties on addition of filler.

Effects of titanate coupling agent on the properties of mica-reinforced nylon-6 composites

Particulate-reinforced thermoplastic composites are designed to improve the properties and to lower the overall cost of engineering polymers. In general, the performance of filled polymers is decided on the basis of the interface attraction of filler and polymers. Therefore, a coupling agent, tetra isopropyl titanate (TYZOR TPT), was used to facilitate the link between filler and matrix (the latter consisting of nylon-6). Mica of different particle sizes (37 and 75 μm) was used. Filler (75 μm mica) was added to the matrix at a 30 wt% concentration. TPT at various concentrations was used to determine the optimal concentration (1 wt%), and henceforth to treat both particle sizes of mica. The tensile strength, Young's modulus, and heat distortion temperature were significantly improved with the incorporation of TPT (1 wt%). Morphological studies revealed strong interfacial interactions between the filler and the matrix on incorporating TPT. POLYM. ENG. SCI., 45:1479–1486, 2005. © 2005 Society of Plastics Engineers

Correlation of mechanical properties of clay filled polyamide mouldings with chromatographically measured surface energies

Inverse gas chromatography (IGC) has been used to investigate the surface properties of calcined kaolins and the effect on the mechanical properties of a Nylon-6 composite containing the clay. Modification of the kaolin with an aminosilane coupling agent lowered its surface energy so that it was comparable with that of the polymer matrix and changed the surface from being acidic to being predominantly basic. The surface of the nylon was also found to be basic but susceptible to hydrogen bonding. Incorporation of the kaolin into nylon changed the mechanical properties and raised the modulus and toughness of the materials. Better results were achieved for the coated kaolin than the uncoated material and this correlated with the surface energy measurements.

Effect of Particle Size of Filler on Properties of Nylon-6

Particulate reinforced thermoplastic composites are designed to improve the properties and to lower the overall cost of engineering plastics. In this study the effects of adding mica with variable particle size on the mechanical, thermal, electrical and rheological properties of nylon-6 was investigated. Composites of nylon-6 with varying concentrations (viz. 5 to 40 weights %) of mica were prepared by twin screw extrusion. The composite showed improved mechanical, thermal as well electrical properties on addition of filler. It is also observed that mechanical properties, electrical properties as well as thermal properties increases with decrease in particle size.

Optimizing the Weld Strength of Ultrasonically Welded Nylon Composites

Ultrasonic welding of thermoplastic composites has become an important process in industry because of its relatively low cost and high quality resultant joints. However, the optimization of this technique has been essentially based on a trial-and-error process. In this report, an L18 orthogonal array design based on the Taguchi method was conducted to optimize the joint strength of ultrasonically welded thermoplastic composites. The materials used were 15 and 35% glass-fiber filled nylon-6 composites. Specimens for ultrasonic welding were welded on a 2000-watt welder and their joint strengths were determined by a tensile tester. The experimental result suggests that the amplitude of vibration, hold time and geometry of the energy directorsare the principal factorsaffecting the joint property of ultrasonically welded nylon composites. Semicircular energy directors were found to weld products of the highest strength. In addition, the joint strength of the parts increases with the fiber content in the composites, but decreases with the moisture of the materials.

Surface Roughness at the Melt/Gas Transition Sites of Gas-Assist Injection Molded Thermoplastic Composites

Gas assist injection molding has proven itself a breakthrough technology in molding thermoplastic composites. However, there are still unsolved problems that confound the overall success of this technique. This report was to study the surface roughness phenomenon occurring at the melt/gas transition sites of gas assist injection molded composite parts. The material used was 35% glass-fiber filled Nylon-6 composite. Experiments were carried out on an 80-ton injection molding machine equipped with a pressure-controlled nitrogen-gas injection unit. A spiral mold was used for all experiments. After molding, a roughness meter was used to measure the surface quality at the melt/gas transition sites of the parts. Various processing variables were studied in terms of their influence on the surface roughness of molded composites: melt temperature, mold temperature, melt filling speed, short-shot size, gas pressure, and gas injection delay time. A scanning electronic microscope was also used to characterize the surface roughness phenomenon of molded parts. It was found that the roughness at the transition sites was mainly caused by the fiber exposure of molded composites. Experimental investigation of a gas assist injection molding problem can help our understanding of the formation mechanism of surface roughness at the melt/gas transition sites, so that steps can be taken to improve the surface quality of molded parts.

The occurrence of surface roughness in gas assist injection molded nylon composites

AbstractGas assist injection molding has increasingly become an important industrial process because of its tremendous flexibility in the design and manufacture of plastic parts. However, there are some unsolved problems that limit the overall success of this technique. The purpose of this report was to study the surface roughness phenomenon occurring in gas assist injection molded thermoplastic composities. The materials used were 15 % and 35% glass‐fiber filled nylon‐6 composites. Experiments were carried out on an 80‐ton injection molding machine equipped with a high‐pressure nitrogen‐gas injection unit. Two “float‐shape” axisymmetric cavities were used. After molding, the surface quality of molded parts was measured by a roughness meter. Various processing variables were studied in terms of their influence on formation of surface roughness: melt temperature, mold temperature, melt filling speed, short‐shot size, gas pressure, and gas injection delay time. Scanning electronic microscopy was also employed to characterize the composites. It was found that the surface roughness results mainly from the exposure of glass fiber in the matrix. The jetting and irregular flows of the polymer melt during the filling process might be factors causing the fiber exposure.

Effects of temperature and water content on impact properties of injection-molded glass nylon-6 composites

Instrumented drop-weight impact tests were conducted for injection-molded short glass fiber reinforced nylon-6 thermoplastic composites. The effects of fiber surface treatments, specimen temperatures and water contents on the impact fracture properties were studied. The first peak load P, or the corresponding absorbed energy E1 was found an appropriate parameter to evaluate the first cracking on specimen surfaces and also to compare the impact performance of thermoplastic composites. The effects of specimen temperatures and drying conditions were also found important in evaluating these materials. Microscopic observations revealed the microfracture mechanisms to explain the above macroscopic mechanical results. Static in-plane fracture toughness properties corresponded well with the impact properties.

Whiskers. VIII. A convenient synthesis of poly(4-hydroxybenzoate) whiskers and their application in composites of nylon-6

Whiskers of poly(4-hydroxybenzoate) [poly(4-HBA)] were prepared by polycondensation of free 4-hydroxybenzoic acid with acetic anhydride and pyridine in a high boiling inert solvent. The purity of the monomer is decisive for the success of the synthesis. For a less pure 4-hydroxybenzoic acid, the preparation of acetylated oligomers with acetylchloride, followed by polycondensation of the isolated oligomers is a suitable alternative. Whiskers, with a solid-solid phase transition at 364°C were obtained, which is the highest temperature reported for this transition so far. Two batches of composites were prepared from nylon-6 using polyester whiskers with an alkaline or an acidic surface treatment. A third batch was prepared using poly(ester-amide) whiskers. The mechanical properties of these composites indicate that the surface treatment does not play any role, and that the poly(esteramide)s are inferior to the polyester whiskers, because they are not single crystals. © 1994 John Wiley & Sons, Inc.

Synthesis of highly conducting nylon‐6 composites and their electrical properties

AbstractHighly conducting nylon‐6 composites are synthesized by exposing nylon‐6 films or fabrics impregnated with an oxidizing agent, cupric chloride, simultaneously to aniline and hydrochloric acid vapors. The conductivity of composite films reaches up to 10−2 S/cm and can be controlled by varying the experimental conditions for the composite synthesis. The effects of the concentration of cupric chloride, exposure time to aniline and hydrochloric acid vapors, and concentration of hydrochloric acid to the polyaniline content and the conductivity of nylon‐6/polyaniline composites are analyzed by means of statistical F test. The morphology change of composite films resulting from the synthesis conditions, conductivity in relation to the morphology, and stability of conductivity to ambient air exposure have been investigated.

A study on composites of Nylon-6 with hollow glass microspheres

The preparation of nylon-6/hollow glass microspheres composites by the RIM procedure, leading to a new material with reduced density and increased stiffness, is described. The shear moduli of these composites show a linear dependency on the filler concentration. By means of a modified Kerner equation the shear moduli of the various glass spheres were calculated. A linear dependency between the shear modulus of a glass sphere and its wall thickness is demonstrated. A direct method for the determination of the shear moduli of those glass spheres having a density lower than the matrix material is presented.