MC Nylon Research Articles

Study on Reinforcing and Toughening Modification of MC Nylon

In this study, we prepared modified potassium titanate whiskers (MPTW) and aluminium oxide (Al2O3) nanoparticles-modified potassium titanate whiskers (AlNPs-MPTW), which were used as reinforcements to produce MPTW MC nylon and AlNPs-MPTW MC nylon, respectively, through in-situ polymerization. Then the thermodynamic stability and mechanical properties of these two kinds of nylon prepared and unmodified MC nylon were studied, proving that AlNPs-MPTW MC nylon possesses better performance. It was found that the prepared AlNPs-MPTW MC nylon with 0.1 wt% AlNP content and 1 wt% MPTW content delivered the optimal properties, specifically tensile strength 97±6 MPa, tensile modulus 3140±45 MPa, flexural strength 116±8 MPa, flexural modulus 3640±53 MPa, and notched impact strength 11.61 kJ/m2. The results showed that multiscale synergistic modified MC nylon possesses remarkable reinforcing and toughening effects, thereby enjoying very broad application prospects.

Crystallization Kinetics of Modified Nanocellulose/Monomer Casting Nylon Composites.

Polyisocyanate and caprolactone were used to chemically functionalize nanocellulose (CNF). Composites of CNF, caprolactone-modified nanocellulose (CNF-CL) and polyisocyanate-modified nanocellulose (CNF-JQ)/MC nylon were fabricated by anionic ring-opening polymerization. The effects of the crystal structure, crystal morphology and crystallization process of MC nylon composites have been characterized by wide-angle X-ray diffraction (WAXD), polarized optical microscopy(POM) and differential scanning calorimetry (DSC). Isothermal crystallization kinetics were analyzed using the Avrami equation, and the crystallization rate, half-time, and Avrami exponent were calculated. The results show that the nucleation effects of CNF-JQ/MC nylon composites is increased with the CNF-JQ increase, and it is best compared with MC nylon, CNF/MC nylon and CNF-CL/MC nylon composites, so CNF-JQ can play the role of effective nucleating agent in MC nylon. We also discussed the non-isothermal crystallization of the composites. Analysis of the Jeziorny and Mo model demonstrates that the Zc values of CNF, CNF-CL, CNF-JQ/MC nylon composites increase, and the F(T) values decrease in order. This indicates that CNF-JQ can better promote the crystallization rate of non-isothermal crystallization of MC nylon. The results of this work demonstrate that CNF-JQ can be an effective nucleation agent and increase the crystallization rate of MC nylon compared with CNF-CL. The activation energy of the composites was studied using the kissing method, and the results showed that CNF-CL decreased the activation energy of MC nylon, and CNF and CNF-JQ increased the activation energy of MC nylon.

Preparation and properties of carboxylated cellulose nanofibers/monomer casting nylon composites

AbstractPolyisocyanate was used to chemically functionalize carboxylated cellulose nanofibers (CNF‐C). Composites of CNF‐C/ monomer casting nylon (MC nylon) and modified CNF‐C/MC nylon were fabricated by anionic ring‐opening polymerization. The mechanical characteristics of the MC nylon composites and the dispersion of the CNF‐C in the MC nylon were studied. The tensile strength and impact strength of composites were first increased with CNF‐C addition, but then decreased as further CNF‐C was added. The composites had good mechanical properties when CNF‐C was added to MC nylon at 1.0 wt%, and the tensile strength and impact strength were increased by 21.2% and 34.9%, respectively, compared to MC nylon. When modified CNF‐C was added at 1.5 wt%, the tensile strength of composites was increased by 47.90%. The addition of CNF‐C causes an increase in the melting point, crystallinity, and crystallization temperature, which was confirmed by differential scanning calorimetry (DSC). The modified CNF‐C had better dispersibility in MC nylon which was confirmed by scanning electron microscopy (SEM).

The optimal design of a piezoelectric energy harvester for smart pavements

The traffic environment contains tremendous mechanical energy due to the dynamic loads of moving vehicles which can be converted into electricity by using piezoelectric materials. Considering the road environmental characteristics, we propose here a piezoelectric energy harvester (PEH) consisting of piezoelectric ceramics that are encapsulated in epoxy resin filler between the MC nylon protective plates. As an illustration, periodic traffic loading is considered and is simulated by a controlled MTS loading, using which the effects of various system parameters on the efficiency of energy harvesting are examined. A theoretical electromechanical model is also developed to predict the energy harvesting behavior of the PEH device. The theoretical predictions agree very well with the experimental measurements, and they both suggest that various load, material, and circuit factors will have diverse effects on output power. To figure out the best collection of all factors and their simultaneous effect on the output performance, we also establish a simple and universal scaling law to reveal the underlying mechanism of the correlation between various systematic parameters. The normalized output power depends only on the normalized intrinsic impedance that consists of all material properties, geometrical, electrical circuit, and loading condition parameters. The optimization strategy may provide a useful tool to guide the design of the PEH device for enhancing the efficiency of energy harvesting by properly selecting the system parameters.

Preparation and properties of wear‐resistant and flame‐retardant polyphenylsulfoneurea/monomer casting nylon copolymers

AbstractA poly(phenylsulfone)‐urea (PPSUU) macro‐activator is synthesized by in situ anionic polymerization of 4,4′‐diaminodiphenylsulfone and hexamethylene diisocyanate. The PPSUU segment is embedded into the nylon molecular chain through copolymerization to improve the wear resistance and flame retardancy of monomer cast nylon 6 (MC PA6) materials. The mechanical properties, thermal stability, friction and wear properties and combustion heat release rate of copolymers with different macro‐activator contents are tested. Results indicate that a small amount of PPSUU can improve the wear resistance and impact properties of nylon materials. The wear loss of MC nylon is 54.8% less than pure MC nylon from 1.049 × 10−8 to 0.474 × 10−8 g/Nm with 6 wt% PPSUU. Moreover, better flame retardancy is verified. The peak of HRR reduced 36.8% from 654 to 413 kw/m2 with 4 wt% PPSUU, accompanied by advanced ignition time and flame extinction time, thus reducing the risk of fire.

Modified α-Al2O3/oil-impregnated monomer casting nylon nanocomposite with both improved friction and mechanical properties

ABSTRACT For shock-absorbing and wear-resistant devices, there is an urgent need for monomer casting nylon (MC nylon) with excellent friction properties and mechanical properties simultaneously. Liquid lubricating oil is known to reduce friction effectively, but it will cause a dramatical decline in the mechanical properties of oil-impregnated monomer casting nylon (OMC nylon). Herein, α-Al2O3 nanoparticles modified by γ-aminopropyl triethoxy silane (APTS) were filled into OMC nylon, and the tribological and mechanical properties of APTS-α-Al2O3/OMC nylon composite were investigated systematically. Compared with OMC nylon, the addition of 0.1 wt% APTS-α-Al2O3 resulted in 19.5% increase in the tensile strength, 33.4% and 29.1% growth in compressive strength and modulus, 30.8% and 33.1% growth in flexural strength and modulus, respectively. Meanwhile, over 44% and 64.8% reduction in the friction coefficient and abrasion quality, respectively, were achieved for the nanocomposite. And the worn surface displayed smooth features, confirming the abrasion resistance of APTS-α-Al2O3. Hence, the combination of lubricating oil and α-Al2O3 is an appropriate choice when excellent mechanical and tribological properties are required to broaden the application field of MC nylon much further.

Polydimethylsiloxane/monomer casting nylon copolymers: Preparation, flame‐retardant properties, and wear‐resistant properties

ABSTRACTIn order to improve the toughness, wear resistance, and combustion properties of the monomer casting nylon (MC nylon) materials, the polydimethylsiloxane (PDMS) segment is bonded to the nylon molecular chain by copolymerization. PDMS/MC nylon copolymers are prepared via in situ anionic polymerization with macro‐activator based on PDMS terminated with hexamethylene diisocyanate. The effects of different macro‐activator content on the mechanical properties, water absorption, thermal stability, friction and wear properties, and combustion properties of the copolymers are characterized. The results show that the impact strength of the copolymer improves significantly (optimally increases by 2.6 times) and the water absorption rate decreases with the increase of PDMS content. The introduction of the silicon–oxygen structure reduces the peak heat release rate of copolymer materials (optimally decreases about 28.7%), while it promotes the decomposition of the system, resulting in a slight decrease in the thermal stability of the materials. Adding 5 wt % PDMS can decrease the wear loss of MC nylon from 6.2 mg of pure nylon to 1.6 mg. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48753.

Simultaneous enhancements of mechanical and thermal properties of monomer cast nylon via polydimethylsiloxane‐modified kaolin

AbstractPolydimethylsiloxane (PDMS)‐modified Kaolin was prepared by the reaction between kaolin and PDMS. MC nylon 6/kaolin and MC nylon 6/kaolin‐PDMS composites with different filler contents were prepared through in situ polymerization. Thermogravimetric analysis and differential scanning calorimetry analysis show that the feeding of kaolin improved thermal stability and crystallinity of nylon. When 1 wt% addition of kaolin‐PDMS, the tensile strength and impact strength of the as‐prepared composites reached a maximum value of 77.7 MPa and 4.5 kJ/m2, respectively, exhibiting remarkable mechanical properties. Meanwhile, the water absorption capacity of the as‐prepared composites was greatly reduced by 60% with the addition of kaolin, and the modified kaolin possesses even better performances. The results show that the treated kaolin can greatly enhance the properties of cast nylon and has an outstanding application prospect.

Piezoelectric Energy Harvesting From Roadways Based on Pavement Compatible Package

Scavenging mechanical energy from the deformation of roadways using piezoelectric energy transformers has been intensively explored and exhibits a promising potential for engineering applications. We propose here a new packaging method that exploits MC nylon and epoxy resin as the main protective materials for the piezoelectric energy harvesting (PEH) device. Wheel tracking tests are performed, and an electromechanical model is developed to double evaluate the efficiency of the PEH device. Results indicate that reducing the embedded depth of the piezoelectric chips may enhance the output power of the PEH device. A simple scaling law is established to show that the normalized output power of the energy harvesting system relies on two combined parameters, i.e., the normalized electrical resistive load and normalized embedded depth. It suggests that the output power of the system may be maximized by properly selecting the geometrical, material, and circuit parameters in a combined manner. This strategy might also provide a useful guideline for optimization of piezoelectric energy harvesting system in practical roadway applications.

Monomer casting nylon/graphene nanocomposite with both improved thermal conductivity and mechanical performance

For high speed transmission devices, there is an urgent demand for MC nylon with high thermal conductivity and high mechanical strength simultaneously. In this study, the MC nylon/graphene nanocomposite has been prepared via pre-dispersed method, which was beneficial to distribute graphene uniformly in the MC nylon matrix. The thermal conductivity of the nanocomposite with 1.0 wt% graphene was 93% higher than that of the pure MC nylon. The impact strength of MC nylon/0.8 wt% graphene nanocomposite increased by 53%. The thermal stability of the MC nylon/graphene nanocomposites has also been improved. We attributed the excellent properties of MC nylon/graphene nanocomposites to the uniform dispersion of graphene in MC nylon matrix, which was confirmed by TEM and SEM characterization. This work provides an effective way for graphene dispersion and obtained MC nylon/graphene nanocomposites with excellent thermal and mechanical properties.

Study on the Tribological Properties of MC Nylon Composites Filled with Hydraulic Oil

Mechanical parts utilized in machinery, such as nylon slider and pulley, should have certain mechanical properties and good tribological properties, so that equipments’ stability and smoothness can be assured. A kind of MC nylon (monomer cast nylon) composites filled with hydraulic oil was studied in this paper. The addition of hydraulic oil changed nylon’s mechanical properties and tribological properties significantly, and improved the material’s toughness and coefficient of friction. The composites have excellent strength, toughness and relatively low coefficient of friction when the content of the hydraulic oil is 4wt%.

Experimental research on mechanical properties of MC nylon

Experimental research on mechanical properties of MC nylon

The Friction and Wear Characteristic Comparison of PMMA and MC Nylon as Spreading Device Pad Material in Copper Coil Forming

The purpose of this study is to compare the frictions and wears characteristics of poly methyl methacrylate (PMMA) and MC Nylon. This study was carried out to investigate the material to be considered as the pad of spreading device material in the copper coil forming machine. To analyze the friction and wear characteristics of those materials the experiments were done as follows. Firstly, the friction characteristic was obtained using a pin-on-disk tester. The experiment was carried on dry and wet friction conditions under paraffin oil lubricant. Secondly, the state of lubrication was investigated using the Stribeck’s Curve. Thirdly, to investigate the wear characteristic, the weight of the pin was measured before and after the friction test. The wear rate is defined as the difference between the initial weight and the final weight. The experimental results show that the friction coefficient of PMMA material was higher than MC nylon. Furthermore, PMMA wear rate also higher than MC Nylon wear rate. The highest wear was achieved on PMMA in dry friction condition, which is 0.00290 grams. MC Nylon was recommended to be used as padding of the spreading device on the coil forming machine.

Synthesis of a novel reactive compatibilizer with large surface area and the application in monomer casting nylon/polyethylene–octene elastomer blends

Graphene oxide (GO) can be used as surfactants in numerous technological fields. For this study, functionalized GO was used as a novel reactive compatibilizer with large surface area to compatibilize immiscible polymer blends. The compatibilizer is composed of three parts with non-polar polymer chain, polar segment and GO sheet, which appears to be of more practical significance and can greatly expand the compatibilizing range. Monomer casting nylon (MC nylon)/polyethylene–octene elastomer (POE) was chosen as the immiscible polymer pairs to investigate the compatibility and comprehensive properties of the compatibilizer. With the incorporation of the novel reactive compatibilizer (GO-TEPAF-POE), the immiscible blends exhibited better compatibility and the dispersion of the minor phase (POE) is remarkably improved without obvious agglomerates. Moreover, GO-TEPAF-POE also acts as multifunctional fillers for MC nylon/POE blends, thus enhancing their mechanical properties and thermal stability. In particular, the notched impact strength values sharply increase by 84 % as opposed to the neat MC nylon. The novel compatibilizer with large surface area may broaden its potential application and fully exploits the extraordinary properties of these appealing carbon nanomaterials.

Creepage Discharge Characteristics Along the Interface Between Two Solid Insulation Materials in GN2

Glass-fiber-reinforced plastic (GFRP) and MC Nylon are widely used in superconducting apparatuses, such as in superconducting fault-current limiters, due to their excellent mechanical and dielectric performance. Many superconducting apparatuses are operated in a high-voltage condition. Thus, an unexpected dielectric accident can occur with damage to a superconducting magnet. Therefore, dielectric experiments on the creepage discharge characteristics of GFRP and MC Nylon were conducted for developing a high-voltage superconducting coil system. For this paper, the creepage discharges along the surfaces of solid insulators in gaseous nitrogen (GN <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), and along the interface between two pieces of solid insulation in contact, were experimented on and analyzed, with respect to ac and dc voltages, at 300 K, under the absolute pressure of 0.1 MPa.

マシニングセンタを用いて抽出した竹繊維のみの成形歯車のかみあいモニターと考察

A plastic gear has the advantages that it is light and can be used without any lubricant, and the disadvantages that its strength is low and that it has a large environmental impact. Therefore, the development of a new gear that maintains the advantages while negating the disadvantages has been proposed. The development of sustainable and reproducible natural materials is especially desired in order to address environmental problems. In this study, a method was therefore devised to extract high quality and highly precise bamboo fibers using a machining center. The hot press method was then used to produce a spur gear, which is a machine element with a complicated shape. Therefore, the present paper describes characteristics of the bamboo fiber gears investigated in some experiments. The results of a strength test showed that the bamboo fiber gear can be used as an alternative to the Mc nylon gear. The results of a meshing test showed that the teeth of a bamboo fiber gear underwent transformation because of the meshing load. In addition, we calculated travel value of meshing point by teeth deformation and compared experimental value of travel value with calculated value. Results show that the experimental deformation value is greater than the calculated value.

Dielectric Characteristics of Solid Insulation Materials With Respect to Surface Roughness

Three kinds of solid insulation materials, such as glass-fiber-reinforced plastic (GFRP), Bakelite, and MC Nylon, are often used in high-voltage superconducting apparatuses as formers and insulation barriers to improve dielectric characteristics. GFRP, Bakelite, and MC Nylon are considered promising candidates as cryogenic solid insulation materials for developing a high-voltage superconducting apparatus due to their excellent dielectric characteristics and robust mechanical strength under cryogenic conditions. The surface roughness of solid insulation materials could differently vary depending on the machining processes. These effects may result in reduced dielectric characteristics. Currently, the details of any relationship between surface roughness and dielectric characteristics under cryogenic conditions have not been analyzed, and there are only a few reports. Thus, a study of the dielectric characteristics of solid insulation materials with respect to surface roughness in cryogenic conditions should be conducted when designing high-voltage superconducting apparatuses with high reliability. In this paper, we present a study on the dielectric characteristics of several materials, such as GFRP, Bakelite, and MC Nylon, used as formers and insulation barriers as a function of surface roughness to assess the effects of changes in surface roughness. Experiments with respect to surface roughness were performed with alternating-current voltages in gaseous nitrogen (GN 2 ) and liquid nitrogen (LN 2 ). A barrier-type solid insulation material was installed between a rod-to-plane electrode system. Penetrating electrical breakdown, creep discharge, and sparkover voltage with a barrier system were observed in the experiments. It was found that the penetrating electrical breakdown, the creep discharge, and the sparkover voltage with a barrier were influenced by the surface roughness of the solid insulation barriers.

Cutting temperature measurement by a micro-sensor array integrated on the rake face of a cutting tool

There is an ongoing demand for temperature measurement during machining processes; however, accomplishing this often proves to be a major challenge. In this paper, we propose a micro temperature sensor that is integrated on the rake face of a cutting tool. Specifically, we propose an array of micro thermocouples, which is implemented on an insert. After calibration, some experiments were conducted with an MC nylon workpiece. The performance of the proposed sensor was evaluated from the obtained thermo-electromotive force and the temperature measurements taken at multiple points.

Reducing bubbles in friction lap welded joint of magnesium alloy and polyamide

The direct joining between AZ31B Mg alloy and MC Nylon 6 using friction lap welding (FLW) was performed over a wide range of welding parameters to clarify the effect of welding parameters on bubble formation for the purpose of obtaining high strength hybrid joints without bubbles. The volume of bubbles in the FLW joints was influenced by the amount of gases generated due to the pyrolysis of Nylon 6 and the amount of gases squeezed out of the joints during welding. An appropriate increase in welding speed, tool rotation rate and plunge depth can reduce the volume of bubbles. Strong FLW joint with area fraction of bubbles <8% was obtained after welding process optimisation.

Hydrolytic degradation of monomer casting nylon in subcritical water

In contrast with the conventional physical methods, sub- and supercritical hydrolysis is not only a more environmentally friendly method to recycle the monomer casting nylon (MC nylon) wastes, but also a more feasible way to produce the corresponding monomer. In subcritical water, MC nylon was decomposed completely into water-soluble oligomers within 45 min at 345 °C and 9 MPa. Fourier transform infrared spectroscopy and X-ray diffraction were employed to characterize the chemical composition and crystalline form changes of the solid products obtained within 30 min of the degradation. Qualitative and quantitative analyses of liquid phase product were performed by liquid chromatography mass spectrometry and high performance liquid chromatography. The yield of the main degradation product ε-caprolactam largely depended on the hydrolysis temperature and reaction time. The maximum yield value reached 89.0% when the reaction time was 75 min. A hydrolytic degradation mechanism of MC nylon in subcritical water is proposed as well.