Durability study of polymeric ballistic panels used in riverine combat boats under humidity-aged and impact fatigue conditions

Microstructural evaluation of an elastomeric composite membrane from two immiscible polymers (UHMWPE and polyurethane) for soft tissue replacement

Ultra-high molecular weight polyethylene (UHMWPE) fibers have good mechanical and physical properties and effective radiation shielding functions, which are significant for aerospace structures. In our previous work, nano-epoxy matrices were developed based on addition of reactive graphitic nanofibers (r-GNFs) in a diluent to form a blend. It is found that improved wettability and enhanced adhesion of the matrices to UHMWPE fibers can be obtained. In this study, a series of nano-epoxy matrices with different concentrations of r-GNFs (up to 0.8 wt%) and different weight ratios of r-GNFs to a reactive diluent (1:4, 1:6, 1:7, and 1:9) were prepared. Composite bundle specimens of UHMWPE fiber/nano-epoxy were fabricated and their tensile behavior was investigated. All load-displacement curves of the UHMWPE/nano-matrix bundle composites under tensile loading showed three regions corresponding to the three deformation and failure stages of the materials: 1) elastic deformation stage, 2) plateau stage, and 3) UHMWPE fiber failure stage. The nano-epoxy with 0.3 wt% of r-GNFs and with 1:6 ratio of r-GNFs to the diluent proved to be the best matrix for UHMWPE fiber composites with enhanced tensile properties. For the resulting composite, the load level and consumed energy in the plateau stage were increased by 8% and 30% over the UHMWPE fiber/pure-epoxy specimens, respectively. This UHMWPE fiber composite with the optimized nano-epoxy matrix also possesses the highest initial stiffness and ultimate tensile strength among all the resulting UHMWPE fiber composites. These results laid a foundation for us to fabricate UHMWPE fiber reinforced composite laminates in the near future.

Ultrahigh molecular weight polyethylene (UHMWPE) fibers have been investigated for years to improve performance with gel spinning process for wide applications in industry. Various spin solvents have been attempted including paraffin oil, decahydronaphthalene (decalin), kerosene etc. However, more work still needs to be done because of environmental issues or long extraction process of the aforementioned solvents. Recently, polybutene was found to be an effective spin solvent for UHMWPE fibers, which is environmentally friendly and widely available on the market. Besides producing high strength fibers, compared to paraffin oil, polybutene can form a gel with UHMWPE showing stronger phase separation behavior at room temperature. Because of this property, more extraction solvents can be saved. It was also demonstrated with experiments that the extraction efficiency is higher than that of the gel fiber formed with paraffin oil. Thus, polybutene has high potential to be used in large-scale production of UHMWPE fibers, which deserves further study. In this work, polybutene with different molecular weight was used to form spin dopes with UHMWPE. The dope concentration for each type of polybutene was also varied to check the effect of molecular weight and dope concentration on fiber properties. Viscoelastic properties of the spin dopes were obtained with parallel plate rheometry while thermodynamic properties of the dopes were characterized with differential scanning calorimetry (DSC) and thermal gravitational analysis (TGA). With optimized processing conditions, high strength fibers were collected and the crystalline structure was examined with wide angel X-ray diffraction (WAXD). DSC and TGA data also provided support for the effect of molecular weight and concentration of polybutene. It can be found that stronger fibers are obtained with lower concentration spin dopes. The viscosity of the dopes and corresponding spinning conditions are significantly affected by molecular weight of polybutene. Extraction efficiency is affected by both molecular weight and dope concentration. To obtain cost-effective superstrong UHMWPE fibers, an optimized design is needed based on the molecular weight of polybutene and the spin dope concentration.

The mechanical properties of a new type of hybrid fiber reinforced concrete (HFRC) which was reinforced by the steel fiber and the ultra-high molecular weight polyethylene (UHMWPE) fiber were researched. The effects of the fiber hybrid ratio on the strength and cracking-resistance properties of concrete were studied through the split-tensile and the cubic-compression tests on 16 types of HFRC. The result shows that the hybrid of the steel fiber and UHMWPE fiber can play a multi-layered role in crack-resistance properties of concrete. The strengths of HFRC is further increased when the UHMWPE fiber are mixed on the basis of the steel fiber. When the fiber volume content of UHMWPE is extra added by 0.3%, the tensile strength increases by 13.64%, 49.49% or 8.08%, and the compressive strength increases by 13.51%, 15.49% or 14.57% compared with the single steel fiber reinforced concrete as the fiber content is 0.5%, 1.0% or 1.5%. The UHMWPE fiber has more obvious effects on material strength compared with polypropylene fiber when it is mixed with the steel fiber reinforced concrete.

Strain hardening geopolymer composites with hybrid POM and UHMWPE fibers: Analysis of static mechanical properties, economic benefits, and environmental impact

ABSTRACTIrradiation surface modification method was used for the surface treatment of ultrahigh molecular weight polyethylene (UHMWPE) fibre to improve the interfacial adhesion of the UHMWPE fibre reinforced PVC composite. The surface characteristics of untreated and treated UHMWPE fibre were characterised by XPS and Fourier transform infra-red spectroscope. The friction and wear properties of the PVC composites filled with differently surface-treated UHMWPE fibres (20 vol.-%), were investigated on a ring-on-block tribometer. Experimental results revealed that irradiation treatment largely increased the mechanical properties of UHMWPE fibre/neoprene/PVC (UF/N/PVC) composites. Scanning electron microscope investigation of worn surfaces of PVC composites showed that surface-treated UF/N/PVC composite had the strongest interfacial adhesion.

This study investigates the physical, mechanical, matrix, and fiber-bridging properties of metakaolin-based engineered geopolymer composites (EGCs) using conventional river sand (RS), or microsilica sand (MS) and polyvinyl alcohol fiber, or ultrahigh molecular weight polyethylene (UHMWPE) fiber. The research evaluated the effects of aggregate type, fiber type, and fiber length (i.e., 10 or 12 mm UHMWPE fiber). Results from compressive strength and single crack tensile tests indicated that the effects of aggregate type, fiber type, and fiber length were statistically similar. All EGC materials manufactured outperformed regular concrete’s compressive strength (30 MPa) by approximately 31%–58% while having densities about 21%–24% lower than that of regular concrete (2.3 g/cm 3 ). The three-point bending test on the notched geopolymer mortars showed that RS specimens exhibited a lower crack tip matrix toughness ( J tip ) value than MS, favoring multiple cracking behavior. All EGC specimens displayed promising pseudo-strain-hardening (PSH) behavior, with PSH strength and energy indices exceeding 1.3 and 2.7, respectively. RS-based composites displayed a more robust PSH behavior compared to those with MS. Notably, the study determined that the tensile strain capacity was more influenced by the PSH energy index than by the strength index, with a coefficient of determination of 0.77 supporting this correlation. The standout composite, incorporating RS and 0.8 vol.% 12 mm UHMWPE fiber, achieved exceptional tensile strain capacities of up to 8%. This performance level is comparable to Grade 60 steel reinforcement, highlighting the potential of EGCs as a sustainable and high-strength alternative for civil infrastructure projects.

The quasi-static and dynamic mechanical behaviours of the concrete reinforced by twisting ultra-high molecular weight polyethylene (UHMWPE) fibre bundles with different volume fractions have been investigated. It was indicated that the improved mixing methodology and fibre geometry guaranteed the uniform distribution of fibres in concrete matrix. The UHMWPE fibres significantly enhanced the splitting tensile strength and residual compressive strength of concrete. The discussions on the key property parameters showed that the UHMWPE fibre reinforced concrete behaved tougher than the plain concrete. Owing to the more uniform distribution of fibres and higher bonding strength at fibre/matrix interface, the UHMWPE fibre with improved geometry enhanced the quasi-static splitting tensile strength and compressive strength of concrete more significantly than the other fibres. The dynamic compression tests demonstrated that the UHMWPE fibre reinforced concrete had considerable strain rate dependency. The bonding between fibres and concrete matrix contributed to the strength enhancement under low strain-rate compression.

Ultrahigh molecular weight polyethylene (UHMWPE) fibers were treated with a coupling agent following the extraction of gel fibers, resulting in modified fibers after subsequent ultra-drawing. The structure and morphology of the modified UHMWPE fibers were characterized and their surface wetting, interfacial adhesion, and mechanical properties were investigated. It was found that the coupling agent was absorbed into the UHMWPE fiber and trapped on the fiber surface. Compared with unmodified UHMWPE fibers, the modified fibers had smaller contact angle, higher crystallinity, and smaller crystal size. The interfacial adhesion and mechanical properties of UHMWPE fibers were significantly improved with increasing coupling agent concentration and gradually reached a plateau value. After treatment with 1.5 wt% solution of a silane coupling agent (γ -aminopropyl triethoxysilane, SCA-KH-550), the interfacial shear strength of the UHMWPE-fiber/epoxy composites was increased by 108% and the tensile strength and modulus of modified UHMWPE fibers were increased by 11% and 37% respectively.

This research paper article thoroughly investigates the tensile, tear, and abrasion properties of high-performance cotton denim fabrics incorporating para-aramid and ultrahigh molecular weight polyethylene (UHMWPE) fibers. It compares these high-performance blended denim fabrics with traditional 100 % cotton fabric material. The findings indicate that fabrics containing UHMWPE and para-aramid fibers demonstrate notably greater strength and durability compared with pure cotton fabrics. Factors such as yarn thickness, twist, fabric weight, cover factor, and the blend proportion of high-performance fibers contribute to enhanced tensile strength and abrasion resistance. Among the tested samples, the blend with 30 % cotton and 70 % UHMWPE fibers, weighing 430 g/m2 (S9), exhibits the most superior performance in terms of tensile strength. These fabrics also exhibit remarkable tear resistance, even under extreme conditions. Sample S9 excels in abrasion resistance, qualifying it for Zone 3 Level 1 protection. The study underscores the potential of these fabrics to offer outstanding protection against abrasion in diverse applications. Additionally, it has been observed that fabrics generally display higher tensile strength and abrasion resistance along the warp direction, owing to a higher yarn density. The analysis of variance and Tukey Honestly Significant Difference (HSD) tests confirm the significant influence of fiber composition on fabric properties based on the statistical analyses that have been conducted.

A technique for grafting acrylic polymers on the surface of ultra-high molecular weight polyethylene (UHMWPE) fibers utilizing 60Co gamma radiation at low dose rates and low total dose has been developed. Unlike some of the more prevalent surface modification schemes, this technique achieves surface grafting with complete retention of the exceptional UHMWPE fiber mechanical properties. In particular, poly(butyl acrylate) and poly(cyclohexyl methacrylate) were successfully grafted onto UHMWPE fibers with no loss in tensile properties. The surface and tensile properties of the fibers were evaluated using Fourier transform infrared/photoacoustic spectroscopy (FTIR/PAS), X-ray photoelectron spectroscopy (XPS), and tensile tests. The reinforcement efficiency of untreated, polymer-grafted, and plasma-treated UHMWPE fibers in polystyrene and a poly(styrene-co-butyl acrylate-co-cyclohexyl methacrylate) statistical terpolymer was characterized using mechanical tensile tests. The thermoplastic matrix composites wer...

High Performance Polyethylene Fibers

Flexible, lightweight, high strength and high efficiently hierarchical Gd2O3/PE composites based on the UHMWPE fibers with self-reinforcing strategy for thermal neutron shielding

ESR study of free radicals in UHMW-PE fiber irradiated by gamma rays

The effect of placement of ultra-high molecular weight polyethylene (UHMWPE) fibres on the flexural properties and fracture resistance of a direct dental composite was investigated. The UHMWPE fibres are increasingly being used for the reinforcement of laboratory fabricated resin composite crown and bridgework. The aim of this study was to assess the effect of a commonly used laboratory fabrication variable on the in vitro strength of beam shaped specimen simulating a three-unit fixed bridge. Four groups (10 specimens per group) of Herculite XRV were prepared for flexural modulus and strength testing after reinforcement with UHMWPE fibres. Two groups of control specimens were prepared without any fibre reinforcement. Half the specimen groups were stored in distilled water and the other groups were stored dry, both at 37 degrees C for 2 weeks before testing. The results of this study showed that placement of fibre at or slightly away from the tensile side improved the flexural properties of the composite in comparison with the unreinforced control specimen groups whilst the mode of failure differed according to fibre position. Scanning electron microscope (SEM) investigation revealed that placement of the fibre slightly away from the tensile side favoured crack development and propagation within the resin bridging the interfibre spaces in addition to debonding parallel to the direction of fibre placement. Laboratory fabrication variables may effect the strength of fibre reinforced bridgework significantly.