Gel Content Research Articles

Fatigue Flexural Properties of Graphite Tailings Concrete Modified with Basalt Fiber

Graphite tailings were solid wastes which were large and difficult to deal with. In order to promote the utilization of graphite tailings and reduce the consumption of natural river sand, this paper replaced part of the natural river sand with graphite tailings and added environmentally friendly green fibers for modification to jointly prepare basalt fiber modification graphite tailings concrete. In order to encourage the adoption of graphite tailings concrete during the construction of roads, it was crucial to fully understand the fatigue and flexural properties of concrete. Through experimental research, this paper analyzed the effects of graphite tailings and basalt fiber mixing on the flexural mechanical properties and fatigue life of concrete, and used solid-state 29Si nuclear magnetic resonance, back scattered electron microscope, and nanoindentation to investigate the interface transition zone. The results indicated that the most effective combination was concrete with a 20% graphite tailings substitution rate and 0.1% basalt fiber by volume, whose flexural strength could be increased by up to 19.10% compared with PC, and when the stress level was 0.6, the fatigue life characteristic value of it was 3.94 times than that of PC. Combined with the results of the microscopic testing, it could be demonstrated that an appropriate amount of graphite tailings could promote the absorption of the Al element, increase the chain length and strength of C-S-H gel, and thereby increase the total content of C-S-H gel. Compared with PC, when the graphite tailings substitution rate was 20%, the hydration degree increased by up to 37.00%, and the total C-S-H gel content also rose by 12.01%. In addition, the admixture of an appropriate amount of graphite tailings would reduce the pores and micro-cracks in the interface transition zone, make the interface transition zone denser, increase its elastic modulus, and reduce the width. At 20 percent of the graphite tailings substitution rate, compared with PC, the minimum width could be reduced by 33.33%, and the elasticity modulus improvement range could reach 33%–40%. These further proved that basalt fiber-modified graphite tailings concrete could strengthen its flexural properties and fatigue life, as well as its feasibility in road engineering applications.

Bilastine-Loaded Transethosome Based Nanogel for the Treatment of Allergic Reactions: An In vitro Characterization

Objective: The goal of the current study was to formulate and evaluate bilastine-loaded transethosomal nanogel. Bilastine has 60% oral bioavailability, which restricts the rate of absorption and dissolution and classifies it under BCS class II drugs, which can be overcome by incorporating bilastine in transethosomal nanogel formulation in the treatment of urticaria. Methods: Bilastine-loaded transethosomes were prepared using a thin film hydration method with different proportions of Tween 80 and ethanol by using a rotary evaporator and incorporated into a transethosomal gel using Carbopol 934 as a polymer by dispersion method. Results: The bilastine-loaded transethosomal formulation was optimized by using the “Box Behnken design” and evaluated for various parameters. The optimized formulation was found to be stable, as determined by the zeta potential of −27.0 mV and polydispersity index (PDI) of 0.167, and vesicle size was found to be 183nm and exhibiting the maximum entrapment efficiency of up to 80.23%. The drug content of the transethosomal gel was found to be 81.56%. The best results were obtained with a transethosomal gel prepared with 1% Carbopol 934 (TF7G2). The optimized batch showed prolonged in-vitro release of bilastine for 8 hrs. Ex vivo skin permeation studies showed 76.23 ± 2.63% permeation in comparison with plain gel. Conclusion: Transethosomal nanogel batches were optimized based on drug content, viscosity, uniformity of drug content, zeta potential, spreadability, pH, drug release, and stability testing, exhibiting good results. The results of this investigation showed that the transethosomal nanogel loaded with bilastine might be used to improve bilastine delivery through the skin with greater bioavailability.

Effect of hydrogen bonding strength on the structure and properties of phase-separated hydrogel from gelatin

Dynamic bonded tough hydrogels often contain phase-separated structures that facilitate multiscale energy dissipation. However, the influence of bonding strength on the phase-separated structures and properties of hydrogels has been understudied. In this work, the hydrogen bonding strength within phase-separated gelatin/acrylic acid copolymer hydrogels was modulated by varying the methyl group content in the acrylic acid copolymer. It was found the mechanical properties of the hydrogels are determined by a synergistic effect between water content and hydrogen bond strength. Both weak and strong hydrogen bonds resulted in the hydrogel with high water content and low mechanical strength. It was observed that the chain dense regions within the hydrogels became more condensed and larger with increasing hydrogen bonding strength. The high water content in gels with strong hydrogen bonds is attributed to the formation of condensed chain dense regions, which prevent significant shrinkage of the hydrogel. The combination of high water content and condensed chain dense regions resulted in sparse chain loose regions within the hydrogel, which provided water channels for ion transport, enabling high ionic conductivity even at a reduced water content of 28.9 wt%.

Effect of Inulin and Psyllium Husk Powder on Gel Properties and In Vitro Digestion of Hypophthalmichthys molitrix and Argopecten irradians Blended Surimi.

Dietary fiber is crucial in enhancing the nutritional and textural properties of surimi-based products. This study investigated blended surimi produced from silver carp and bay scallops, with the addition of different amounts (0%, 0.5%, 1%, 2%, and 3%) of inulin (INU) or psyllium husk powder (PHP) for their textural properties, protein conformation, and in vitro digestibility. The addition of INU negatively affected gel strength. However, incorporating 2.0% PHP into the blended gel improved gel strength and water-holding capacity by 8.01% and 0.79% compared to the control, respectively. Furthermore, PHP significantly increased the total sulfhydryl content and surface hydrophobicity of the blended gels (p < 0.05). Additionally, increases in endogenous fluorescence intensity accompanied by a blue shift were observed, indicating that the fluorophores (Trp and Tyr) were sequestered into a more non-polar environment due to conformational changes. The incorporation of PHP enhanced both the quality and digestibility of the blended surimi. This study provides a novel perspective for developing surimi-based food with improved quality, augmented digestion, and enhanced absorption.

Early Strength and Microscopic Mechanisms of Alkali-Metal Hydroxide-Activated Tungsten Tailings

The excellent mechanical properties of alkaline-activated tailings are essential for their increased use in building materials. While numerous studies have been conducted on activated tailings, the strength of alkaline-activated tungsten slag has not been extensively explored due to the low reactivity of silicon and aluminum in these tailings. This research delves into the early unconfined compressive strength of tungsten tailings activated by two alkali solutions (NaOH and KOH) at three different alkali concentrations (mass ratio of alkali to tungsten tailings), cured at 80 °C over periods of one day, three days, and seven days. The study finds significant improvements in the stability of tungsten tailings when forming (C, N)-A-S-H or (C, K)-A-S-H gels with both alkalis. Scanning Electron Microscope (SEM) results show that the morphology of the (C, N)-A-S-H gels transitions from membranous to flocculated and then to a three-dimensional network as the NaOH content and curing time increase. Conversely, the (C, K)-A-S-H gels primarily exhibit thin-film morphology with some three-dimensional network structures. The presence of flocculation and three-dimensional mesh in the gels fosters the formation of a robust skeletal structure, enhancing the strength of the samples. Furthermore, specimens treated with NaOH solution exhibit a higher gel content compared to those treated with KOH solution. These factors contribute to the superior efficacy of sodium hydroxide in enhancing the strength of tungsten tailings compared to potassium hydroxide. X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) results identify the formation of new phases such as pirssonite, buetschliite, potassium bicarbonate, and potassium carbonate. The first new phase results from the carbonization of excess NaOH solution, while the latter phases arise from the carbonization of excess KOH solution. These carbonization processes negatively impact the strength of the materials.

Non‐Isocyanate Carbamate Acrylates: Synthesis, Characterization, and Applications in UV 3D Printing

ABSTRACTIn this paper, two synthetic routes for non‐isocyanate carbamate acrylates (CAs) were explored. Four amino alcohols reacted with ethylene carbonate respectively forming carbamate alcohols. Additionally, carbamate amines were synthesized through the reaction of diethylene glycol with dimethyl carbonate, followed by the reaction of 4‐methylcyclohexane‐1,3‐diamine. Five kinds of CAs were synthesized via oxa‐Michael addition of carbamate alcohols and aza‐Michael reactions of carbamate amines with neopentyl glycol diacrylate (NPGDA), respectively. The resulting intermediates and final CAs were characterized by electrospray ionization high‐resolution mass spectrometry (ESI‐HRMS), 1H NMR, and FT‐IR spectroscopy. The photopolymerization kinetics of the CAs were investigated using FT‐IR spectroscopy. Under UV irradiation and initiation by 1 wt% 2‐isopropylthioxanthone (ITX) for 30 s, the double bond conversion of the CAs synthesized by oxa‐Michael addition were over 95%. The resulting CAs can be UV cured to form a transparent film with a gel content of 90%–95%, a hardness of 4–5 H, and a flexibility of 1 mm. A formulation consisting of 79 wt% CA2, 20 wt% NPGDA, and 1 wt% ITX was applied for 3D printing to produce various models with smooth surfaces, high precision, and excellent flexibility.

Influence of alkali molarity on compressive strength of high-strength geopolymer concrete using machine learning techniques based on curing regimes and temperature

The compressive strength behavior of high-strength geopolymer concrete (HSGPC) has been studied in this research work with varying alkali concentration using the novel machine learning techniques. The alkali concentration in the activation solution plays a significant role in the geopolymerization process and affects the resulting compressive strength. In this research work, the range between 4 M and 16 M for alkali molarity (M), 18 kg/m3 and 160 kg/m3 for NaOH and 41 kg/m3 and 229 kg/m3 for NaSi was collected from literature and used in the various design mixes of this exercise. This was necessary because higher alkali concentrations promote a more efficient dissolution and activation of the aluminosilicate compounds, leading to increased geopolymerization and the formation of more calcium silicate hydrate (C-S-H) gel. The increased C-S-H gel content contributes to improved strength development. However, there is an optimal alkali concentration range for the sustainable production of geopolymer concrete, and exceeding this range can have a negative impact on compressive strength and ecofriendly handling of concrete. A total of fifty-three records were collected from literature and deployed in modeling the compressive strength (Fc) considering various curing regimes. Three symbolic machine learning techniques such as genetic programming (GP), evolutionary polynomial regression (EPR), and the artificial neural network (ANN) are used in this research model. The relative importance values for each input parameter were also evaluated, which indicated that all factors have significant impacts on (Fc), but Age (i.e., curing regime) has the most influence compared to FA, NaOH, and CAg then the other inputs. From the model relations between the calculated and predicted values, it can be shown that the decisive model, ANN produced line of parametric equation of y = 0.995x, and produced performance indices; MAE of 2.13 MPa, RMSE of 2.86 MPa and R-squared of 0.981, which makes the ANN the most reliable model in agreement with previous applications of the technique. These are against the poor performance of the EPR and GP, which produced R-squared less than 0.8 with higher error rates. The Taylor chart and the variance distribution, which further compares the accuracy and variances of the developed models support the outcomes. Generally, alkali molarity has shown its potential in the production of HSGPC due to its role in the reactivity phases of the concrete formulation; hydration, activation, pozzolanic, and geopolymerization reactions producing the gel needed for the strength gain in HSGPC.

Porous photo-crosslinked hybrid networks based on poly(trimethylene carbonate-co-ε-caprolactone) and recombinant human-like collagen

Hybrid hydrogel networks were prepared from recombinant human-like collagen (rh-collagen) and poly(trimethylene carbonate-co-ε-caprolactone) (P (TMC-co-ε-CL)) to overcome the mechanical and bioactivity limitations associated with the respective individual networks. Both polymers were functionalised with methacrylic anhydride to yield photo-crosslinkable materials. Porous hybrid networks of different compositions were prepared by photo-crosslinking frozen mixtures of solutions of the functionalized polymers in acidified DMSO. After extraction with water, the obtained networks had the intended compositions, high porosities and gel content. Upon equilibration in water, the total water content was found to increase with increasing collagen content. The tensile properties and suture retention strength (SRS) of the hybrids were improved compared to a rh-collagen network. In particular, the 17:83 wt% rh-collagen:P(TMC-co-ε-CL) network had considerably higher toughness and SRS, showing promise as a hybrid hydrogel network to be further investigated for tissue engineering purposes.

Synthesis of Dispersed Magnetic Fe3O4 Nanohydrogel Based on Gelatine by Gamma Irradiation for Toxic Heavy Metals Removal

AbstractHeavy metals are among the problematic groups of contaminants. They are discharged from various industries. The wastewater disposed by heavy metals is causing major hazards to the environment. Different hydrogels based on Gelatin (gelt/AAm/EDTA) and nano- (Fe3O4/gelt/AAm/EDTA) were prepared by gamma radiation at 60 KGy and employed for heavy metals elimination. The structure and surface morphology of the manufactured hydrogels were confirmed with FTIR, X-ray, surface area, and SEM. The prepared hydrogels were characterized in terms of their gel content. The swelling properties were studied as a function of time. This research aims to investigate the adsorption properties of diverse hydrogels concerning heavy metal ions, specifically copper, cobalt, and nickel. The impact of key experimental factors, including initial metal concentration, temperature, time, and pH, was inspected via batch adsorption experiments utilizing atomic absorption spectroscopy. It was found that the adsorption of Cu+2‏, Co+2‏ and Ni+2‏ ions is pH-dependent, and the optimal pH for adsorption of Cu+2 is pH 4‏, Co+2 ‏is 5, and Ni+2‏ is 4. The highest metals removal was copper, nickel, and cobalt ions by nano (Fe3O4/gelt/AAm/EDTA) hydrogel with removal percent 98.5% for Cu+2, 96.8%for Ni+2, and 93.9%for Co+2. Graphical Abstract

Effect of h-NS Content on the Viscosity, Morphology, Gelation, and Mechanical Properties of the Modified-rPET from Bottle Waste

This research developed the modified-recycled poly (ethylene terephthalate) (modified-rPET) filament by decreasing the crosslinked-gel content inside the filament, by adding various contents of hydrophobic nanosilica (h-NS). This research also studies the viscosity, morphology, h-NS dispersion, and mechanical properties of the modified-rPET/h-NS, by using a rotational rheometer, a scanning electron microscope, a micro-XRF spectrometer, and a universal testing machine, respectively. rPET flakes were dried to deplete the moisture. Then, they were mixed with additives and h-NS at 0, 1, 2, 3, 4, and 5 pph, and were extruded to be compound using twin screw extruder. The modified-rPET/h-NS extrudates were investigated into two parts. Firstly, was observed on the process-ability, morphology, and gel content along the filament. Consequently, the viscosity, mechanical properties, and h-NS dispersion were investigated. The results showed that the best formulation that is easy to process and has the lowest gel content along the filament, was NS1. Other results, shear-thinning rheology behaviors were observed for all formulations. The mechanical properties, including ultimate tensile strength and elongation at break decreased, as the h-NS content increased. At higher content of h-NS (NS4 and NS5), the gel content increased significantly, therefore the h-NS agglomeration occurred, which was different from crosslinked gels.

Early properties and reaction mechanism of hybrid alkali-activated cements (HAACs)

Geopolymers have received extensive attention due to their greenhouse effect. However, the application of geopolymers has been restricted by their workability and manufacturing technique. Hybrid alkali-activated cements (HAACs), which are transition materials between cement and geopolymers, have gradually been developed. The chemical reactions of HAACs are complicated, and adjusting their performance is difficult. In this study, the competitive reactivities and phase contents of commonly used HAACs with different raw material compositions and curing conditions are examined. The reaction degrees of the clinker (RoC), C-(A)-S-H+N(C)-A-S-H gel and unreacted amorphous particle (UAP) contents were calculated. The experimental results indicated that the quantity and structure of the gel were optimized when the Si2O/Na2O and Na2O contents of HAAC-G3 were 1.5 and 4 %, respectively, and the cement: mineral admixture ratio was 1:4. Moreover, a large amount of N-A-S-H with a dense structure was produced by alkali reactions rather than cement hydration reactions in HAAC-G3; these reactions improved the macroscopic mechanical properties. Additionally, the effects of steam curing on the properties of the HAACs were slight because of the internal water competition reaction mechanism. This research clarified the influence of different coordination methods on the internal reaction mechanism of HAACs and could be used to promote the engineering application of HAACs. Moreover, HAACs play an important role in mitigating greenhouse effects worldwide.

Comparison of composite resins containing UV light-sensitive chitosan derivatives in stereolithography (SLA)-3D printers

This study produced composite resins by combining acrylate, chitosan (CH), carboxymethyl chitosan (CMCH), hydroxypropyl chitosan (HPCH), and hydroxyethyl chitosan (HECH) to create materials suitable for use in 3D stereolithography (SLA) printers. Tripropylene glycol diacrylate (TPGDA), urethane acrylate (UA), and photoinitiator (Diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO)) were mixed. CH and its derivatives were added separately to the resin to obtain composite resins. The mechanical test results are clear; the optimum TPGDA: UA ratio was 1:1, the cure time was 60 s, and the TPO ratio was 1 %. The optimum viscosity of the resin is 340–350 cP. Hydrophobic/hydrophilic properties of cured composite resins were examined. The addition of CH and its derivatives to the resin caused a decrease in compressive strength. Adding up to 2.5 % CH, CMCH, and HECH to the resin significantly increased the tensile strength of the resin, giving it flexibility. The gel content of cured composite resins was between 97.72 % and 96.11 %. The cured composite resins demonstrated high chemical and solvent resistance to HCl, NaOH, and HF but exhibited limited resistance to toluene and chloroform. The accelerated UV aging test results show that adding CH derivatives to the resin makes the composite resin more prone to photooxidative aging.

Renewable Photo-Cross-Linkable Polyester-Based Biomaterials: Synthesis, Characterization, and Cytocompatibility Assessment.

The present work consist of the synthesis of photo-cross-linkable materials, based on unsaturated polyesters (UPs), synthesized from biobased monomers from renewable sources such as itaconic acid and 1,4-butanediol. The UPs were characterized to assess the influence of polycondensation reaction temperature and cross-linking time on their final properties. For this purpose, different UV irradiation exposure periods were tested. Homogeneous, uniform, and transparent films were obtained after 1, 3, and 5 min of UV exposure. These cross-linked films were then characterized. All materials presented high gel content, which was dependent on the reaction's temperature. The thermal behaviors of the UPs were shown to be similar. In vitro hydrolytic degradation tests showed that the materials can undergo degradation in phosphate-buffered saline (PBS) at pH 7.4 and 37 °C, ensuring their biodegradability over time. Finally, to assess the applicability of the polyesters as biomaterials, their cytocompatibility was determined by using human dermal fibroblasts.

A comparative analysis of carboxymethyl tamarind kernel gum-based hydrogels for ciprofloxacin delivery

In the current study, four different combinations of hydrogels were synthesized using carboxymethyl tamarind kernel gum (CMTKG), synthetic polymers: polysodiumacrylate (PSA) and polyacrylamide (PAM) and Graphene Oxide (GO) as a filler, and Ciprofloxacin (Cip) as a model drug and then characterized. The swelling behavior of hydrogel reveals the order as Distilled Water (DW) (pH 7) > pH 7.4 > pH 1.2. The gel content (%) of the hydrogels was 79 (D1), 68.7 (D2), 88 (D3), and 76 (D4). Further, studies such as drug loading and drug release were carried out at simulated pH 7.4, pH 5.5, and pH 1.2, which reveals that the maximum drug release (%) was exhibited by D3 (86), followed by D1 (82), D4 (70), and D2 (61) at pH 7.4. The Korsmeyer-Peppa's model suggested the best fit with R2 = 0.99 for all. Additionally, the antibacterial activity reveals the inhibition zone (mm) for 24 (D1), 16 (D2), 30 (D3), and 19 (D4) hydrogels. The cytotoxicity of hydrogels indicated that the cell survival rate was >68 % in <250 μg/mL concentration for all hydrogels. Hence, incorporating GO can potentially enhance the drug release ability, bactericidal property, and cell survival rate of the hydrogels.

Effect of β-sitosterol+γ-oryzanol-based oleogels on protein conformation and gel properties of Nemiperus virgatus surimi.

The impact of β-sitosterol+γ-oryzanol-based oleogels or peanut oil on the protein conformation and gel quality of Nemiperus virgatus surimi was evaluated. A significant reduction in gel strength, texture parameters and water holding capacity (WHC) of surimi was found as oil concentration increased (P < 0.05). However, compared with peanut oil, the gel strength, hydrophobic interaction and disulfide bond content of surimi gel containing oleogels increased by 6.919%, 32.635% and 12.409%, respectively, when the oil concentration was 10 g kg-1. Both oleogels and peanut oil could enhance the whiteness of surimi gel. Oleogels induced the unfolding of surimi proteins, and promoted the conformational shift from α-helix to β-sheet structure. Furthermore, oleogels filled the gaps of protein networks to make the microstructure of surimi gel more compact and uniform, improving the WHC and reducing the cooking loss. γ-Oryzanol+β-sitosterol-based oleogel alleviated the adverse influences of direct addition of peanut oil on the gel and textural properties of surimi products. © 2024 Society of Chemical Industry.

Thermally stimulated bio-acrylate based detachable adhesives with sustainable bonding-debonding design

The electronics and automotive industries utilize acrylic adhesives extensively. Their exceptional mechanical strength, accompanied by their permanent nature, renders recycling impracticable. Present work has successfully synthesized acrylate biopolymer based detachable adhesive, which is both eco-friendly and sustainable. Glycerol, from mustard oil, was oxidatively-dehydrated to synthesize acrylic acid, which along with dimethyl glyoxime was chain polymerized to obtain an eco-friendly acrylic based hot melt detachable adhesive (AAHMDA). Mechanical strength of prepared adhesive was tested through thermo-mechanical bonding-debonding cycles on glass, wood, and metal. In three tests of 0.2 g adhesive against specific applied stress on all surfaces, metal (1494.49 N/m2) and wood (1851.17 N/m2) remained intact for 2 h and 30 min. Maximum cleavage stress (applied weight) on glass, wood, and metal slides, using 0.2 g adhesive, was found to be 26503.61 N/m2 (1200 g), 19824.71 N/m2 (950 g), and 26328.24 N/m2 (1300 g), respectively, when repeatedly tested for 15 cycles. Gel contents and water absorption capacity of sample were found at 99.79 % and 38.78 %, respectively. Prepared AAHMDA possesses the capability to create a robust mechanical bond that is readily detachable when heated, which makes it a cost effective adhesive. Owing to its strong bonding and simple detachment procedure, AAHMDA appears to have a promising future in materials research, sustainability initiatives, and changing industry demands.

Towards Photocrosslinkable Lyotropic Blends of Organosolv Lignin and Hydroxypropyl Cellulose for 3D Printing by Direct Ink Writing.

Polymer blends containing up to 70% organosolv lignin content and lyotropic cellulose derivatives have been established as "lignin inks" for direct ink writing of fully biobased 3D parts. However, a fast-crosslinking mechanism is needed to improve throughput and design space. In this paper, UV-photocrosslinkable organosolv lignin/hydroxypropyl cellulose inks are formulated through doping with common photocrosslinkers. The most potent photocrosslinkers for neat hydroxypropyl cellulose, lignin and their blends are determined through a series of DOEs. Hydroxypropyl cellulose is significantly more amenable to photocrosslinking than organosolv lignin. The optimal photocrosslinkable ink formulations are printable and exhibit up to 70% gel content, although thermal post-curing remains essential. Chemical, thermal, and mechanical investigations of the photocrosslinked 3D parts evidence efficient crosslinking of HPC through its hydroxyl groups, while lignin appears internally plasticized and/or degraded during inefficient photocrosslinking. Despite this, photocrosslinkable inks exhibit improved tensile properties, shape flexibility, and fidelity. The heterogeneous crosslinking and residual creep highlight the need to further activate lignin for homogeneous photocrosslinking in order to fully exploit the potential of lignin inks in DIW.

Rheological analysis of network structure of raw natural rubber prepared by different processing techniques

The performance of raw natural rubber (NR) is dominated by its network structure, particular the levels of long chain branching (LCB) and entanglement. Here, three type of raw rubbers were prepared using different processing methods for commercial grade NRs. Linear and nonlinear viscoelastic behaviors, as well as stress relaxation, were analyzed to access their network structures. The third relative harmonic, phase angle, and first to second quarter-period integral ratio of stress curve were utilized as indicators for the nonlinearity of samples. By combining these values with flow activation energy and characteristic times, it can be confirmed that naturally coagulated NR showed higher elasticity than acid-coagulated NR due to high levels of LCB and entanglement, and hot air drying could lead to chain degradation. These findings correlated with molecular weight parameters, gel content and Mooney viscosity results. This research establishes a method for monitoring raw NR quality and predicting its properties.

Ultraviolet cross‐linked ultra‐high molecular weight polyethylene fiber laminate: Preparation and mechanism analysis for its excellent mechanical properties

AbstractThe development of high‐performance ultra‐high molecular weight polyethylene (UHMWPE) fiber laminate is of great significance in the field of bulletproof materials. However, due to the poor heat resistance of UHMWPE fibers, it is challenging to achieve exceptional mechanical properties in laminates prepared via hot‐pressing. In this study, we employ a self‐made ultraviolet (UV) cross‐linked fully drawn yarn of UHMWPE (UVFDY), which exhibits excellent heat resistance, to prepare a UVFDY/unsaturated polyester resin (UPR) laminate through hot‐pressing. The laminate possesses outstanding mechanical properties, which includes high Barcol hardness (~40 HBa), high tensile strength (~800 MPa), and high storage modulus (~13.7 GPa at 25°C), surpassing those of most conventional UHMWPE fiber laminates. Its remarkable mechanical properties are primarily attributed to the highly cross‐linked networks of cured UPR and the stable structures (gel content ~89%, crystallinity ~81.5%, orientation ~93%, and smoother fiber surface) of UVFDY during hot‐pressing. This work not only provides valuable insights into the preparation of high‐performance UHMWPE fiber laminates but also promotes applications for the self‐made UV cross‐linked UHMWPE fiber.Highlights Novel laminate possesses high Barcol hardness. The tensile strength and storage modulus of novel laminate are excellent. UV irradiated fiber with high structural stability during hot‐pressing.

Diatomaceous Earth‐Containing Linseed Oil‐Based Environmentally Friendly Hydrophobic Coatings

AbstractThe use of bio‐based building blocks for the synthesis of polymers is increasing day by day. Coatings prepared by modifying bio‐based building blocks such as linseed oil (LO) and diatomaceous earth (DE) are very promising. In this study, bio‐based hydrophobic coatings were prepared by cationic photopolymerization technique using epoxidized linseed oil (ELO) and dimer diamine‐modified diatomaceous earth. The bio‐based coatings with hydrophobic properties were prepared by using the spin coating method. ELO was characterized by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H‐NMR). The thermal properties of the prepared coatings were determined by thermogravimetric analysis (TGA). The pendulum hardness, pencil hardness, and gel content of the prepared coatings were examined. Also, the hydrophobicity of the obtained bio‐based coatings was determined by contact angle measurements. The highest contact angle among the investigated compositions was found to be 110°.