Polyester Resin Research Articles

Synchronously strengthening and plasticizing of unsaturated polyester resin based on styrene-maleic anhydride oligomer

To synchronously strength and plasticize unsaturated polyester resin (UPR), maleic anhydride were directly added in the unsaturated polyester resin solution and form the styrene-maleic anhydride oligomer (SMAO) without initiation. The creating SMAO cross link with UPR by curing reaction, and the prepared UPR resin exhibit higher tensile, elongation, bending strength and higher impact strength simultaneously, 0.45, 0.36, 0.76 and 0.12 times than UPR matrix, SMAO-UPR exhibits obvious plastic fracture characteristics; The DSC result indicates that the curing degree of SMAO-UPR is 96.55% which is 1.45% lower than that of UPR; The TG result indicates that MA and St mainly form an alternating copolymer below 90°C. The SEM and DMA result indicates that SMAO improves the morphology and structure which shows plastic deformation of UPR, and there is a certain interface effect between SMAO and UPR. Compared with the traditional method of large molecular weight SMA modified UPR, this method of reinforcing UPR is better for mechanical property, easy to operate, inexpensive, and highly applicable in industrial production.

Study on the impact of water absorption processes on the application of wood waste in composite material production

The issue of recycling and reusing waste from the wood processing industry has garnered significant attention from researchers, as effective solutions could yield economic benefits while mitigating environmental impacts. This article focuses on the development of artificial wood using unsaturated polyester resin combined with waste materials from carpentry workshops, specifically investigating its water absorption properties. Research findings indicate that the water absorption coefficient of the samples increased with longer immersion times, higher organic filler content, and larger particle diameters. The calculated density reveals a broad spectrum of solid industrial boards that can be produced from these compositions, suggesting that consistent forming conditions enhance economic viability. Notably, optimal results were achieved with samples made from mixed wood powder without prior sorting, which contributes to reduced production costs, aligning with the study's objectives. Furthermore, the investigation highlighted that the water absorption coefficient escalates with increased soaking time, organic filler content, and particle size, indicating that in humid environments, it is advisable to limit both filler content and particle size to maintain performance. Overall, the studies confirm the feasibility of utilizing wood powder as a filler, with varying particle diameters imparting distinct characteristics to the final product. These findings underscore the potential for innovative approaches to wood waste management in the industry.

Thermal analysis of mortar based on crushed dune sand

This study investigates the thermal decomposition behavior of mortars formulated using crushed dune sand and thixotropic polyester resin. Thermal analysis techniques, including Differential Scanning Calorimetry (DSC), Differential Thermal Analysis (DTA), and Gravimetric Thermal Analysis (GTA), were employed to characterize the thermal transitions, decomposition stages, and stability of these mortars. Results indicate that crushed dune sand maintains consistent glass transition (Tg) and crystallization temperatures (Tc) when integrated into the mortar matrix, highlighting its thermal stability. However, the melting point (Tm) varies due to the presence of the resin, which significantly influences the composite’s thermal behavior. Decomposition analysis reveals two major weight loss stages: water evaporation between 200°C to 400°C and organic decomposition of the resin between 700°C to 800°C, with minimal weight change beyond 800°C, indicating thermal stability. The DTA results exhibit distinct endothermic reactions related to dehydration and dehydroxylation, along with a pronounced exothermic peak around 400°C, signifying resin decomposition. Elemental analysis confirms that the crushed dune sand is predominantly silica with minimal impurities, making it suitable for construction applications. This research contributes to a deeper understanding of the thermal behavior of polymer-modified mortars, with implications for enhancing thermal and mechanical properties in construction materials.

Advances in the development of polyester resin composites: a review

Advances in the development of polyester resin composites: a review

Thermal and mechanical properties of high-performance polyester nanobiocomposites reinforced with pre-treated sunn hemp fiber for automotive applications

The objective of this study is to create high-performance nano biocomposites by utilizing unsaturated polyester resin (PE) reinforced with pre-treated short (2 cm) lengthened sunn hemp (SH) fibers and by incorporating 5 % nanoclay (hydrophilic bentonite) through the compression molding technique. The addition of 5 % nanoclay to the biocomposite significantly increased the flexural strength by approximately 165 % for H2O2-treated SH fiber and 148 % for KMnO4-treated SH fiber, when compared to untreated fibers. This enhancement was achieved through phase separation, intercalation, and exfoliation between the SH fibers, polyester resin (PE), and 5 % nanoclay. In particular, the H2O2-treated SH fiber nanobiocomposite exhibited a 43 % higher flexural strength compared to its corresponding biocomposite. The incorporation of nanoclay significantly decreased the water absorption of the bio-composites from 11.86 % in the untreated samples to a minimum of 2.76 % in the H2O2-treated SH/PE nanobiocomposite. The study suggests that short SH fiber/PE/nanoclay nanobiocomposites could be used as effective alternatives to synthetic composites in various applications, including the aerospace industry, household products, and automotive interior components such as side panels, seat frames, and central consoles. Additionally, they could be utilized in exterior parts like door panels and dashboards.

Insights into the curing and thermal behavior of orthophtalic unsaturated polyester resin with organically modified montmorillonite nanoclay

Insights into the curing and thermal behavior of orthophtalic unsaturated polyester resin with organically modified montmorillonite nanoclay

Autoclaved aerated concrete reinforced by polymeric pins

Autoclaved Aerated Concrete (AAC) is a lightweight and sustainable building material known for its thermal insulation and acoustic properties. However, its relatively low mechanical strength limits its use in load-bearing applications. This paper introduces the concept of incorporating unsaturated polyester resin (UPR) pins into AAC blocks to improve compressive and flexural strength of the material. Pin diameters of 4, 6, 8 and 10 mm were studied, oriented at 90° and 45° in relation to the AAC main plane. The effects of the UPR/AAC interface were analyzed through microscopy. The results point to a substantial increase in mechanical strength of the reinforced AAC, wherein smaller pins with orientation of 45° and 90° presented the best behavior under flexural (up to 298%) and compressive loading (up to 183%), respectively.

Potential for material valorization of composites (glass fiber in polyester resin) in concrete: performance evaluation on mortar

IntroductionGlass fibers with polyester resin structural composites are highly sought after in many sectors such as transportation industries, thanks to their low density and fairly good mechanical properties. However, their end-of-life management is not yet satisfactory. Composites mostly end in energy recovery in the best-case scenario or, worse, in landfills. Transformation into shreds and powders for reuse as a new source of raw material for the construction sector (concrete) is an economically and environmentally attractive recovery solution. The present study investigates the development of a concrete filled with glass/polyester composite shreds.MethodsTo this end, rheological (cone spread) and physico-mechanical (density and mechanical strength in flexion and compression) characterization tests were carried out. Several mix designs were tested in order to understand the impact of introducing composite shreds as a substitute for sand. Composite shreds were introduced in the following ratios by volume: 0, 1, 1.5, 2, 2.5, 3, and 7% with water and cement ratio equal to 0.5, 0.6, and 0.7.Results and discussionThe results obtained indicate that workability decreases with the substitution of sand by shreds. For a substitution of sand by shreds of 2%, it is relatively small, and the pouring of the mortar is still feasible. The decrease can be attributed to the water absorption of the composite shreds. Concerning mechanical results, for formulations with a substitution percentage of composite shreds lower than 3%, the mechanical strength (both compression test and flexure test) is slightly higher than that of the reference sample. The increase in compressive strength that can be observed is at its maximum, equal to 10%, compared to that of the reference sample. These results are in line with density results, which are also slightly higher than that of the reference sample. This effect can be attributed to water absorption of composite shreds and the filling effect of the powders. For a percentage of substitution equal to 7%, the mechanical strength is lower than that of the reference sample (30% decrease), with a compressive strength equal to 33 MPa (47 MPa for the reference sample). For this percentage of substitution equal to 7%, a decrease in density is also observed (6% decrease) and can be explained by the porosity created by the incorporation of the composite shreds into the mortar.

Improved interfacial compatibility between unsaturated polyester resin and rice straw fibers after non-washing treatment with Ca(OH)2

The agricultural industry produces a substantial volume of rice straw (RS) annually, highlighting the importance of recycling RS for sustainable materials. However, the poor interfacial compatibility between RS and polymers often leads to drawbacks in their composites, such as water-swelling and limited tensile strength. Here, we propose a novel approach using Ca(OH)2 that offers several distinct advantages: enhancement of interfacial compatibility, elimination of the need for water washing, and formation of calcified hybrid particles on fiber surfaces by capturing CO2 from the atmosphere. The non-washing calcified rice straw (NCRS) fibers were used to fabricate composites with unsaturated polyester resin (UPR), resulting in NCRS/UPR composites exhibiting significant enhancements in water resistance and mechanical properties compared to RS/UPR composites. The NCRS/UPR composites achieved a water absorption rate below 25 %, thickness swelling rate below 10 %, and tensile strength of 19.9 MPa. This work comprehensively explored the mechanism underlying these achievements through experimental studies. Findings suggest that CaCO3 particles involving with released lignin act as an interfacial bridge between RS fiber surface and UPR, resulting in significantly improved properties. This approach demonstrates promising prospects as a simple and eco-friendly methodology for manufacturing RS-based composite materials.

3D Printable Polymeric Composite Material with Enhanced Conductivity Achieved by Affinity Matching.

Polymer-based conductive composites are lightweight, low-cost, and easily processable materials with important applications in various fields. However, achieving highly conductive and 3D printable polymer-based conductive composites remains challenging. In this study, we successfully developed a highly conductive composite suitable for direct ink writing 3D printing using unsaturated polyester resin as the polymer matrix and graphene nanosheets as conductive fillers and rheological modifiers. Due to the well-matched affinity between graphene nanosheets and unsaturated polyester, the graphene nanosheets aggregate within the unsaturated polyester, forming a 3D conductive network. Moreover, the shearing force during direct ink writing 3D printing induces the orientation of the 2D graphene nanosheets, significantly enhancing their conductivity along the printing direction. At room temperature, the unsaturated polyester resin/graphene composite shows a high conductivity of 69.9 S m-1 while maintaining excellent 3D printability. Structures printed using this material exhibit improved heat dissipation and electromagnetic shielding performance. The reported unsaturated polyester resin/graphene nanosheet composites demonstrate outstanding electrical and heat conductivity and excellent processability, making them promising candidates for applications in electromagnetic shielding, printed electronics, and other fields.

An investigation on the mechanical, thermal and tribological properties of newly developed polyester composites made with Pistachio shell particles for industrial applications

The drive for sustainability and addressing environmental concerns has led to the productive use of bio-waste. This research investigates the potential of pistachio (Pistacia vera) nut shell particles as a novel filler in polyester composites. The study explores the use of these nut shells as a reinforcing material in polyester-based composites to evaluate their mechanical and thermal properties. Pistachio shell particles (PSP) are mixed with polyester resin in varying weight fractions (0%, 1%, 3%, and 5%) to create a new type of composite. The impact of filler content, impingement angle and striking velocity on the erosive wear behavior of these composites are also studied. The mechanical results for the composites revealed that incorporating PSP filler resulted in the maximum rise in tensile (96.61%), impact strength (66.66%), micro-hardness (52.94%), under loading of 5 wt% of PSP filler. However, the composite with 3 wt% of PSP filler, resulted in the maximum rise of flexural strength (135.65%) and flexural modulus (45.28%). Results showed that, composites with 5 wt% of PSP filler exhibited superior erosive resistance. An optimal parameter setting is determined for minimum erosion rate and subsequently validated by conducting confirmation experiment as per Taguchi methodology. Different modes of material removal, wear craters and other qualitative attributes are examined by a scanning electron microscopy during erosion experiment of the samples. Thus, the utilization of agro/food wastes in the development of bio-based products holds significant potential and offers the possibility of replacing conventional materials in various industrial applications.

Improving mechanical and thermal properties of unsaturated polyester resin by adding automotive glass waste

Improving mechanical and thermal properties of unsaturated polyester resin by adding automotive glass waste

Effect of thermal shocks on the interfacial bond strength of sandwich composites built with rigid and soft materials produced through extrusion process

The mechanical behavior and adhesion strength of the sandwich composite, which consists of a flexible and a rigid material, were examined using extruded polylactic acid (PLA) and thermoplastic polyurethane (TPU). Three types of binders were combined with the appropriate hardeners to bond the extruded materials. The fabricated specimens are subjected to a different number of thermal shock cycles, with a maximum and minimum temperature of 80 °C and −18 °C, respectively. The sandwich composite's mechanical properties, including tensile, flexural, and impact strength, were assessed after 20, 40, and 80 cycles of thermal shock. The results indicated that the ductility of PLA material was significantly impacted by the thermal shock cycles. After completing the maximal thermal shock cycles, the composites joined with polyester resin exhibited a lower strength reduction in the impact specimens. Maximum tensile strength of 22.3 MPa, flexural strength of 31.6 MPa, and impact strength of 8.3 J were recorded prior to the application of thermal shocks to the specimens. The specimens that were bonded with epoxy resin recorded the maximal tensile, flexural, and impact strength. Following the thermal shock cycles, the composites bonded with epoxy resin exhibited a lesser reduction in tensile and flexural strength, while the composites bonded with polyester resin showed a lower strength reduction for impact specimens. The tensile and flexural specimens encountered a 7.54 % and 20.24 % reduction in strength, respectively, after undergoing 80 cycles of thermal shocks. The impact specimens experienced an 8.62 % reduction in strength.

Mechanical analysis of polyester resin using digital image correlation and finite element method

The primary objective of this study is to perform a comprehensive mechanical analysis of unsaturated polyester (UP) resin under unidirectional tensile loading. The Digital Image Correlation (DIC) technique was employed to accurately determine the mechanical properties of the material, with full-field strain measurements used to extract both transverse and longitudinal strains through virtual extensometers. This approach facilitated the precise calculation of the Poisson’s ratio of the UP resin. The results obtained via DIC demonstrated strong correlation with the experimental data obtained through the machine’s control software, particularly in capturing vertical displacement and longitudinal strain with high precision. The Poisson’s ratio was found to be 0.46. To further validate the DIC findings, Finite Element Analysis (FEA) was conducted. The FEA results aligned closely with the experimental data, confirming the reliability and accuracy of the DIC method in this context. The values of Young’s modulus determined from experimental tests and FEA data were 3620.02 MPa and 3598 MPa, respectively, with a percentage error of only 0.61%.

Toward new applications of terpenes in polymeric materials: Synthesis and characterization of myrcene‐modified unsaturated polyester resins

Abstractβ‐Myrcene, a terpenic monomer, holds potential for developing sustainable polymer‐based materials with enhanced properties. This study examines the synthesis of a myrcene‐based monomer and its incorporation into unsaturated polyesters, focusing on polymerization, curing, and final properties. Unsaturated polyesters were synthesized with varying myrcene‐based monomer content (6, 12, and 24 mol%), phthalic anhydride, maleic anhydride, propylene glycol, ethylene glycol, and diethylene glycol. Polymerization achieved conversion values of 0.92–0.93, resulting in polyesters with molar masses between 1400 and 1700 g mol−1 and dispersity indices of 2.0 to 2.3. Nuclear magnetic resonance (1H NMR) demonstrated short branch formation in myrcene‐modified polyesters and a high maleate‐to‐fumarate isomerization rate (92.66%–95.7%), affecting carbon–carbon double bonds per polyester mole (2.27 to 4.28) and final resin performance. Rheological analysis in a styrene solution (70/30 wt%) indicated shear‐thinning behavior, with viscosities ranging from 0.59 to 3.8 Pa·s, suggesting branching affects chain entanglement. Differential scanning calorimetry (DSC) revealed decreased curing enthalpy with increasing myrcene content, and it was inferred that myrcene's double bonds did not participate in curing. Glass transition temperatures of cured polyesters (70–107 °C) correlate with enthalpy trends. Thermal stability of myrcene‐modified polyesters is similar to the reference polyester, highlighting myrcene's potential as a sustainable monomer for customizable unsaturated polyesters.

Vinyl methyl oxazolidinone and dimethyl itaconate as styrene substitutes for conventional high‐temperature unsaturated polyester resins

AbstractStyrene substitution is a major area of interest in the unsaturated polyester resins (UPR) industry and research. For most styrene‐free UPRs the unsaturated polyester (UP) formulation was tailored for less toxic reactive diluent monomers (RDM). The main challenge is finding a RDM that can directly substitute styrene in industrial UPR formulations without deterioration of resin and thermoset properties. Therefore, this study concerns vinyl methyl oxazolidinone (VMOX®) as a reactive diluent monomer for industrial high‐temperature UPRs. VMOX® and styrene were compared with dimethyl itaconate (DMI), methyl methacrylate, 2‐hydroxyethyl methacrylate, isobornyl methacrylate, triethylene glycol dimethacrylate and 1,4‐butanediol dimethacrylate. Further, the properties of produced resins and thermosets were investigated. The most striking result was comparable glass transition temperature, crosslink density, and residual monomer content of VMOX®‐ and styrene‐based thermosets. Subsequently, DMI was applied as a reactive co‐diluent for VMOX®‐based resins and thermosets. Significant improvement of VMOX® conversion during resin curing was observed. In conclusion, VMOX® is an excellent candidate for direct styrene substitution in industrial high‐temperature UPRs. Furthermore, the application of DMI as a reactive co‐diluent improves the reactivity of VMOX®‐based resins. The application of VMOX® and reactive co‐diluent monomer certainly creates new possibilities for direct styrene substitution in conventional UPR formulations.

Benefits of Environmentally Friendly Plaster on Mechanical Properties When Combined with Polyester Resin and Hardener Are Examined under Compression and Tension.

Recently, plaster has gained increasing attention as a mechanical and environmentally friendly option and is an effective alternative to traditional cement products. Additionally, polyester has an effective impact on the mechanical properties of materials, in addition to being one of the most environmentally friendly materials. However, studies are still ongoing to reach the best ratios of polyester resin, polyester hardener, and gypsum plaster that can improve mechanical properties. This research aims to investigate the impact of these components at various ratios (30%, 45%, and 60%) of gypsum plaster weight on the mechanical properties of plaster material. This study is carried out by conducting compression and tensile tests for three ratios, which are considered among the most important mechanical tests according to their applications. In addition, the environmental emissions resulting from the three different ratios of plaster are evaluated to determine their environmental impact. This study found that the largest ratio (30%) was the most effective from an economic and mechanical point of view, while achieving lower carbon emissions compared to the other ratios, which enhances the trend towards achieving the environmental goals of the Kingdom of Saudi Arabia's Vision 2030 to reach zero emissions. This study is highly significant both in terms of scientific research and practical application across a range of industries, since it integrates the enhancement of material performance with the achievement of environmental sustainability requirements.

Controlling Chelation and Esterification in Pechini Synthesis for Enhancing Chemical Looping Steam Methane Reforming using LaFeO3 Perovskite.

The properties of an oxygen carrier, such as crystalline structure, textural properties, and surface chemical species, significantly influence the redox performance in thermochemical redox applications. This study presents the synthesis of various lanthanum orthoferrite (LaFeO3) perovskites by adjusting Pechini synthesis parameters, including chelating agent ratio, calcination temperature, and solution pH. A larger surface area emerged as a dominant factor contributing to improved redox performance. The porosity of the polyester resin proves crucial in achieving a large surface area and a small particle size for the oxygen carrier. This goal could be attained by controlling the pH of the precursor solution. A low degree of chelation or precipitation may lead to uneven cation distribution, resulting in the enrichment of trace hydroxide impurities. These impurities can suppress the reducibility of particles during the looping experiment. Various investigations, using XRD, XPS, XAS, SEM, and N2 physisorption, revealed that porosity and crystallinity can be controlled by altering the synthesis parameters.

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.

Nansilver@Unsaturated Polyester Resin: Nano-hybrid for Improvement of Mechanical Strength and Chemical Resistance of Concrete

Nansilver@Unsaturated Polyester Resin: Nano-hybrid for Improvement of Mechanical Strength and Chemical Resistance of Concrete