Properties Of Unsaturated Polyester Resin Research Articles

Modified montmorillonite combined with intumescent flame retardants on the flame retardancy and thermal stability properties of unsaturated polyester resins

Modified montmorillonite‐containing phytic acid (PA‐MMT) has been prepared by acid treatment and then introduced into unsaturated polyester resin (UPR) with an intumescent flame retardant (IFRs). The flame retardancy and thermal degradation of UPR/IFRs/PA‐MMT were evaluated by a limiting oxygen index (LOI) test, a vertical burning test (UL‐94), a thermogravimetric analysis (TGA), and a cone calorimeter test (CCT). Besides, the mechanical properties were studied by a universal testing machine. The LOI value of UPR/IFRs/PA‐MMT composites was increased to 29.2%. The CCT results indicated that the incorporation of PA‐MMT and IFRs significantly improved the combustion behavior of UPR. The results of the mechanical properties indicated that 1.5 wt% loading of PA‐MMT in UPR/IFRs showed the highest improvement in flexural strength and tensile strength. The flame‐retardant mechanism of PA‐MMT/IFRs was examined and discussed based on the results of combustion behavior and char analysis.

Effects of Dimethyl Methylphosphonate, Aluminum Hydroxide and Ammonium Polyphosphate on the Flame Retardancy and Thermal Properties of Unsaturated Polyester Resin

The flame-retardant unsaturated polyester resin with dimethyl methylphosphonate (DMMP), aluminum hydroxide (ATH) and ammonium polyphosphate (APP) were prepared and found to exhibit a high flame-retardant efficiency and low cost. The different dosages of flame retardant effect on the flame retardant were evaluated based on limiting oxygen index (LOI) measurements, vertical burning test (UL94), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). A LOI value of 29.8% and a UL-94 vertical burning V-0 rating was achieved for UPR with 10phr DMMP, 15phr ATH and 9phr APP. In the presence of DMMP, ATH and APP, the dense char structure were produced in the combustion process of UPR.

Constructing phosphorus, nitrogen, silicon-co-contained boron nitride nanosheets to reinforce flame retardant properties of unsaturated polyester resin

In this work, we reported the synthesis of boron nitride nanosheets containing phosphorus, nitrogen and silicon-co-existing elements as high-performance nanofillers in unsaturated polyester resin (UPR) for the first time and precisely performed structural characterization to confirm the covalent functionalization. After incorporating 3 wt% into UPR matrix, combustion behavior of UPR nanocomposites was investigated by cone calorimeter, demonstrating the obvious reduction of 28.2% and 38.0% in PHRR and THR, respectively. TG-IR-MS coupling technique was employed to reveal thermal degradation and toxic volatiles such as CO, phenyl derivatives, hydrocarbons. On the basis of gaseous and condensed phase, we reasonably proposed the flame retardant mechanism of boron nitride with phosphorus, nitrogen and silicon elements to increase flame retardant properties of UPR. It is expected to exploit covalent functionalization of boron nitride and its nanocomposites with high flame retardance.

The Physico-Mechanical Properties of Unsaturated Polyester Resin Filled with Huracrepitan Pod for Wall Tiles Application

Huracrepitan pod was the fibre material used for this research and unsaturated polyester resin was used as the matrix. The huracrepitan pod was crushed with the aid of the Thomas-Willey laboratory mill machine, model 4 and was sieved using a standard sieve of 250 µm. The crushed huracrepitan pod was then soaked in a standard solution of 20% Sodium Hydroxide for 24 hours and washed with distilled water. It was later dried in the oven for an hour for final removal of moisture. I00 g of unsaturated polyester resin was reinforced with huracrepitan pod particles of filler loadings of 0 g, 10 g, 20 g, 30 g, and 40 g., while 90 g, 80 g, 70 g and 60 g of unsaturated polyester resin were reinforced with 20 g, 30 g and 40 g huracrepitan pod.The composites obtained were cut into dumbbell shapes and characterized to assess their performance. The hardness was enhanced to the maximum of 99.00 Shore A at 40% filler loading the percentage water absorption was found to be 0.3g. Pure unsaturated polyester resin recorded hardness of 94.67 Shore A, and water absorption of 0.30g and the percentage elongation optimum was found to be 15% at 40% filler loading and 2.5% at 0% filler loading. The results indicated that the use of huracrepitan pod particles as reinforcement can enhance the properties of polyester composites. It was observed that the samples with the highest filler loading absorbed more impact energy and also increased the elongation percentage. The application of Huracrepitan pod as filler in this work improved the mechanical properties of the thermosetting polymer.

Mechanical and thermo-gravimetric properties of unsaturated polyester resin blended with FGD gypsum

A major disadvantage of polymeric materials is their flammability and generation of toxic gases under fire. Mechanical and thermo-gravimetric properties of an unsaturated polyester resin blended with Flu-Gas Desulfurization (FGD) gypsum were assessed. Limited open flame tests were also performed. Results indicate that ambient mechanical properties of polyester resin can be enhanced with up to 50% FGD gypsum content. TGA results show significant improvement in mass retention proportional to gypsum content. Under direct fire, FGD gypsum can form a protective physical barrier on the resin’s exterior surfaces. FGD gypsum can potentially be an effective and low-cost fire-resistance additive for polymers.

The impact of crosslinking monomers concentration on the properties of unsaturated polyester resins

<p>The article illustrates the preparation of unsaturated polyester as well as the mechanical and thermal properties of his copolymers with crosslinking monomers (styrene and diethylene glycol dimethacrylate). The starting polyester was obtained from maleic anhydride, propylene glycol and isobutanol. The prepared series of unsaturated polyester resins were subjected to different studies concerning evaluation of their viscosity, mechanical and thermal properties and also dynamic mechanical behaviour (DMA).</p>

New composites based on waste PET and non-metallic fraction from waste printed circuit boards: Mechanical and thermal properties

Abstract Influence of the addition of three different non-metallic fractions (NMF), obtained by processing of printed circuit boards (PCBs), on the mechanical and thermal properties of unsaturated polyester resin (UPR) based composites were studied in this paper. UPR, based on products of PET depolymerization, and NMF were characterized using FTIR, NMR, optical microscopy and SEM/EDS analysis. Cross-linking density (ν), storage modulus (G′), damping factor (tanδ) and glass transition temperature (Tg) of the composites were determined from the DMA testing. Tensile (σt) and flexural (σf) strength, and micro Vickers hardness indicated good composite performance under static load. Thermal and flame resistant properties were analyzed by TGA/DTG and UL-94 flammability test whereby V-2 category of appropriate composite was achieved. Composites with satisfactory mechanical and thermal properties reflected synergetic effect of constituents obtained from waste materials.

Mechanical Properties of Unsaturated Polyester Resin (UPR)-Mortar and its Potential Application to Restore the Strength and Serviceability of Patched Reinforced Concrete Slab

Degradation of reinforced concrete could occur in various forms including spalling of concrete cover as a result of reinforcement corrosion. The degradation would shorthen the service life of the reinforced concrete structure. Patch repair method may be employed to recover this type of degradation using a suitable patch repair material. The authors have developed a patch repair material made from unsaturated polyester resin (UPR)-mortar. In this paper, the mechanical properties of this material which includes compressive strength, elastic modulus, flexural strength and bond strength are highlighted. Comparisons are also made with the normal mortar to emphasize the superior properties of UPR-mortar. Based on these properties, the potential application of UPR-mortar for repairing damaged reinforced concrete slab is examined through finite element simulation. It is pointed out that the tensile stress intensity in the UPR-layer is reduced with a consequence of reducing a risk of cracking in the repair zone. In addition, the patching of damaged zone with UPR-mortar could minimize the deflection.

Synergistic effect of combined dimethyl methylphosphonate with aluminum hydroxide or ammonium polyphosphate retardant systems on the flame retardancy and thermal properties of unsaturated polyester resin

ABSTRACTA series of flame-retardant unsaturated polyester resin (UPR) were prepared by the addition of dimethyl methylphosphonate (DMMP) with various amounts of aluminum hydroxide (ATH) or ammonium polyphosphate (APP) as the flame retardants. The combustion resistance effects of ATH/DMMP and APP/DMMP systems were evaluated by limiting oxygen index test and vertical burning test (UL-94). The thermal properties of UPR were investigated by thermogravimetric analysis. The structure of char was observed by scanning electron microscopy. DMMP incorporated with ATH or APP improved the flame retardancy and thermal properties of UPR. However, the fire-retardant mechanism of these two systems were different: The ATH/DMMP system provided synergistic effect in charring property of the UPR, produced great amount of residual char, and thus revealed the excellent flame retardancy. The APP/DMMP system further improved the flame retardancy of the UPR due to the change in the residual char structure rather than the increase in the production of char.

Optimization of mixing process and effect of multi-walled carbon nanotubes on tensile properties of unsaturated polyester resin in composite materials

Multi-walled carbon nanotubes (MWCNTs) were mixed with Unsaturated polyester resin (UPR) using the stir method at high temperatures. The mixing temperature and hardener ratio were optimized based on compression properties and the exothermic temperature. In the experiment, 60 °C and 1 wt.% of Methyl ethyl ketone peroxide (MEKP) were chosen for the mixing condition and catalyst concentration, respectively. MWCNTs with different weight fractions (0.05, 0.1, 0.2 and 0.3 wt.%) were dispersed to investigate the effect of MWCNTs on tensile properties of the UPR, and it was found that 0.1 wt.% of MWCNTs showed the best performance in this range of fiber weight fraction due to a higher strength (42.14 %), modulus (14.33 %) and fracture strain (37.17 %) than pure UPR. The state of dispersion and arrangement of fibers were examined by a Field emission Scanning electron microscope (FE-SEM) according to fracture surfaces. Similarly, the FE-SEM also showed better results with 0.1 wt.% of MWCNTs mixed in the UPR.

Morphology development and mechanical properties of unsaturated polyester resin containing nanodiamonds

AbstractUnsaturated polyester/styrene (UP) resin was filled with nanodiamonds (NDs) containing carboxyl and methacrylate functionalities using mechanical mixing. Field emission SEM exhibited a uniform dispersion of tightly bound aggregates of nanosized spherical NDs with good interfacial interaction. Rheological measurements exhibited a step increment in the shear viscosity of a UP/ND suspension at 0.6 wt% ND resembling a percolation state at this loading. Shear viscosity data supported by dynamic mechanical analysis results suggested the development of effective ND particles in which ND aggregates were covered by only polyester macromolecules. Accordingly, the morphology of UP/ND composites approached a quasi‐percolation state at 0.6 wt% in which effective ND particles were connected thoroughly, instead of direct ND−ND contact, forming a co‐continuous polyester phase covering the ND particles. Based on such morphology, DSC and Fourier transform infrared analysis suggested the development of heterogeneous microgels in cured UP resin containing NDs which in turn governed the overall mechanical properties of the composites. © 2017 Society of Chemical Industry

Optimization of Thermal and Mechanical Properties of Unsaturated Polyester Resin as a Binder in Polymer Concrete for Manufacturing Precision Tool Machine Bases

This study investigates the effect of unsaturated polyester resin chemical composition on the coefficient of thermal expansion, damping properties, flexural strength, tensile strength and hardness. The resin is used as binder in polymer concrete for manufacturing the bases of precision tool machines in previous work published by the authors. Resins of various ratios of styrene-ARAPOL and methyl methacrylate (MMA)-ARAPOL were made and their curing kinetics was studied using viscosity measurements and exothermic reaction temperature profiles. The resins were studied using dynamic mechanical analysis and in-house thermal expansion measuring devices. It was found that ARAPOL–MMA (60:40) has the highest damping factor of 5.46%, and the thermal expansion coefficient of 7.98 × 10- 5/°C. This composition also has the optimum flexural and tensile strengths at 128 MPa and 58.6 MPa

Preparation of Unidirectional Grewia Serrulata Fiber-Reinforced Polyester Composites and Evaluation of Tensile and Flexural Properties

ABSTRACTPartially biodegradable composites were prepared using bast fibers extracted from Grewia Serrulata trees with unsaturated polyester resin. Different durations of fiber pretreatment and volume fraction variations were tried for fabricating the composites. Hand lay-up technique was used for the fabrication; tensile strength and flexural strength of the specimens were tested following American Society for Testing and Materials (ASTM) standards. It is found that the mechanical properties of Grewia Serrulata bast fiber-reinforced unsaturated polyester composites are superior in comparison with relevant properties of unsaturated polyester resin. Such natural fiber-reinforced composites are adaptable in applications such as automotive interiors, partition walls, and false ceilings and ensures easy material disposal ways at the end of service life as raw materials used are mostly biodegradable.

The effect of carbon nanotubes/NiFe2O4on the thermal stability, combustion behavior and mechanical properties of unsaturated polyester resin

The incorporation of MWCNT@NiFe2O4into the UPR matrix exhibit significant improvements in flame retardancy and mechanical properties, compared to that of pure UPR.

The investigation of flammability, thermal stability, heat resistance and mechanical properties of unsaturated polyester resin using AlPi as flame retardant

The influence of aluminum dialkylphosphinate (AlPi) on the flammability, thermal properties and mechanical properties of unsaturated polyester resins (UPRs) was investigated. A series of flame-retarded UPR loading with AlPi were prepared. The flammability and thermal stability of these UPR composites were investigated with limiting oxygen index (LOI), UL-94 vertical burning and themogravimetric analysis test. The structure and morphology of char residues were examined with Fourier transform infrared and scanning electron microscopy (SEM). Additionally, thermomechanical property of cured composites was characterized by dynamic mechanical analysis (DMA). The results showed that the AlPi excellently improved the flame retardancy of UPR, the LOI increased from 21 to 29.5 with the increasing of AlPi and UPR-AlPi25 (25 %) passed V-0 classification. The char residue of UPR-AlPi25 at 700 °C was 11.17 % in nitrogen and 20.83 % in oxygen, suggested that interaction between AlPi and UPR strengthened the char-formation ability and the thermal stability of the UPR/AlPi systems. The SEM showed that the surface of the char for UPR-AlPi25 was strong and dense and flexural fracture surfaces of UPR/AlPi composites showed a homogeneous morphology. The DMA curve indicated the T g was greatly improved with the increasing of AlPi.

Effect of the modified silica Nanofiller on the Mechanical Properties of Unsaturated Polyester Resins Based on Recycled Polyethylene Terephthalate

Unsaturated polyester resin (UPe)-based nanocomposites and fumed silica Aerosil R812S, R805 and R816, and R200 modified with phenyl terminal group, R200NPh, were prepared. UPe resins were synthesized from maleic anhydride and products of glycolysis, obtained by polyethylene terephthalate depolymerization with dipropylene glycol in the presence of tetrabutyl titanate catalyst. The obtained unsaturated polyesters were characterized by acid, hydroxyl, and iodine values and by FTIR and NMR analysis. The microstructural analysis of the prepared nanocomposites, performed by using transmission electron microscopy, confirmed that silica nanoparticles formed chain-like aggregates in the polymer matrix. The presence of modified silica nanoparticles had no influence on the glass transition temperature and thermal stability of polyester matrix. The tensile modulus, stress at break, and hardness of cured products increased with increasing silica content. The impact strength of cured samples was not influenced by the silica content. POLYM. COMPOS., 38:538–554, 2017. © 2015 Society of Plastics Engineers

Cure and strain monitoring of novel unsaturated polyester/phenolic resin blends in the vacuum infusion process using fibre Bragg gratings

In recent years, a few research studies have been published on the blending of unsaturated polyester and phenolic resins for the purpose of improving the fire properties of unsaturated polyester resins. However, there has been no published study on the cure and strain monitoring of unsaturated polyester/phenolic blends during composite manufacturing. In this study, non-crimp triaxial glass fabric preforms were infused with the unsaturated polyester/phenolic blends, and the strain developments inside the composites were monitored using fibre Bragg grating sensors, as the long and complex curing stages were progressing at different temperatures. Strain-free fibre Bragg grating sensors and also thermocouples were utilised for temperature monitoring and compensation in order to obtain true strain developments and residual strains. The results were associated with a study presenting the cure analyses of unsaturated polyester/phenolic blends. The unsaturated polyester and the phenolics were found to be incompatible and exhibited different curing mechanisms in the blends, which were also observable in the strain development results. This paper has been the first attempt to (i) process these novel resin systems in the vacuum infusion process and (ii) monitor the long, complex and high-temperature cure cycles and the strain developments in the vacuum infusion process using fibre Bragg gratings.

Influence of FRP Waste on the Properties of Unsaturated Polyester Resin Based Artificial Marble

There is a lot of glass fiber reinforced plastic (FRP) waste every year. Its low utilization rate and serious secondary pollution cause many problems. In this paper, FRP waste was added to enhance unsaturated polyester resin based artificial marble. The effects of FRP waste content and its particle size on the mechanical properties of artificial marble were discussed. Results show that the FRP waste content and its particle size are closely related to the mechanical properties of artificial marble. The artificial marble with FRP waste particle size of less than 0.075 mm and content of 12.5 wt % got the best mechanical properties, whose flexural strength was 23.72 MPa and compressive strength was 79.13 MPa, increased by 75.8 % and 128.1 %, respectively, compared with the strength of artificial marble with no FRP waste.

Biobased vinyl levulinate as styrene replacement for unsaturated polyester resins

ABSTRACTVinyl levulinate (VL) is used as a biobased reactive diluent in styrene (St)‐free unsaturated polyester resins (UPR). The reactivity ratios for the radical copolymerization of VL with diethyl fumarate (DEF) are determined by the Jaacks method (rVL = 0.01 and rDEF = 0.81 at 60 °C in DMSO‐d6). The properties of UPRs having a stoichiometric ratio between unsaturated groups from the UPR and either St or VL are compared. Defect‐free, slightly yellow, transparent, and rigid thermosets are obtained after a mild curing cycle. Due to unfavorable reactivity ratios about 5.5 wt % of unpolymerized VL remains inside the network and acts as plasticizer. Consequently, compared with St‐based ones, VL‐based UPRs exhibit lower α relaxation (Tα = 180 and 100 °C, respectively), lower elastic moduli at the rubbery plateau (G′ = 108 and 107 Pa) and lower mechanical properties as measured by three points bending tests. Strain at break (εf = 1.8 ± 0.2%) and Charpy impact strength (∼2.7 ± 0.3 kJ m−2) are comparable independently of the RD chemical nature. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 3356–3364

Structural mass irregularities and fiber volume influence on morphology and mechanical properties of unsaturated polyester resin in matrix composites

This paper presents the comparative results of a current study on unsaturated polyester resin (UPR) matrix composites processed by filament winding method, with cotton spun yarn of different mass irregularities and two different volume fractions. Physical and mechanical properties were measured, namely ultimate stress, stiffness, elongation%. The mechanical properties of the composites increased significantly with the increase in the fiber volume fraction in agreement with the Counto model. Mass irregularities in the yarn structure were quantitatively measured and visualized by scanning electron microscopy (SEM). Mass irregularities cause marked decrease in relative strength about 25% and 33% which increases with fiber volume fraction. Ultimate stress and stiffness increases with fiber volume fraction and is always higher for yarn with less mass irregularities.