Unsaturated Polyester Composites Research Articles

Flame retardancy of unsaturated polyester composites with modified ammonium polyphosphate, montmorillonite, and zinc borate

ABSTRACTAmmonium polyphosphate (APP) was modified using a new method, where the resulting modified APP (MAPP) was obtained by mixing APP with unsaturated polyester resin (UPR). MAPP was more effective in improving the flame retardancy of UPR than APP which was due to the improved dispersion of MAPP in UPR composite. Then, the UPR composites were prepared based on dimethyl methylphosphonate, MAPP, montmorillonite, and zinc borate. Finally, the flame‐retardant and mechanical properties of the UPR composites were analyzed using the limited oxygen index (LOI), thermogravimetric analysis, UL‐94 vertical burning test, scanning electron microscopy, cone calorimetry, mechanical tests, and viscosity measurements. The LOI and UL‐94 tests showed that the flame‐retardant properties clearly improved with the addition of fillers in the UPR composites compared to pristine UPR. The synergistic effect of Si‐ and P‐containing flame retardants in this composite resulted in the LOI value increasing from 18.9 to 31.3% and achieved the UL‐94 V‐0 rating. Moreover, the heat release rate was lower than the pristine UPR. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47180.

Mechanical, morphological, structural and dynamic mechanical properties of alkali treated Ensete stem fibers reinforced unsaturated polyester composites

Present study deals the surface morphology and structural composition analysis of alkali (NaOH) treated 2.5% 5.0% and 7.5 wt% Ensete stem fiber obtained from the Ethiopian Ensete ventricosum plant. Treated Ensete fibers reinforced unsaturated polyester (UP) composites were characterized in terms of tensile, flexural, surface morphology and dynamic mechanical properties. Mechanical test results revealed that 5.0 wt% alkali treated Ensete fibers/UP composites showed 14.5% and 43.5% increase in flexural strength and Young's modulus respectively, with relative to untreated Ensete fibers/UP composites. Storage and loss modulus value also highest for 5.0 wt% alkali treated Ensete fibers/UP composites. Moreover, a positive shift in glass transition temperature (Tg) of composites after alkali treatment and tensile fracture surface morphology indicates better interfacial interaction in treated Ensete fibers/UP composites. Overall we concluded that 5.0 wt% treated Ensete fibers satisfactorily and effectively improved mechanical, morphological and dynamic properties of UP for various engineered and hi-tech applications.

Comprehensive Characterization of Natural Cissus quadrangularis Stem Fiber Composites as an Alternate for Conventional FRP Composites

Health and sustainability are the major concerns that drive researchers to find novel materials to replace artificial hazardous materials. In this investigation, the mechanical properties of Cissus quadrangularis Stem Fiber (CQSF) reinforced with unsaturated polyester composite were optimized by varying the fiber length and content. To substantiate the findings, chemical property, thermal property, microstructure, and water absorption property were analyzed. Progressive enhancement of mechanical properties was observed with increasing the fiber content and fiber length up to 30 wt.% and 40 mm. However, beyond that limit, there was a decline in the strength due to improper bonding of fiber with matrix. Optimal values of mechanical property for CQSF composite were obtained at 30 wt.% fiber content and 40 mm fiber length, which are comparable with that of common artificial fiber-reinforced polymer composites.

Effect of carbonized watermelon rind powder on the mechanical and thermal properties of unsaturated polyester composites: A special insight to chemical resistance and value addition

AbstractThis study focuses on the preparation and characterization of bio‐based filler derived from natural fruit waste and its utilization in unsaturated polyester composites. Particle size analysis, energy dispersive x‐ray spectroscopy, and Fourier transform spectroscopy were used to characterize the size and composition of the filler namely carbonized watermelon rind filler, called carbonized watermelon rind filler. The filled composites (0%, 5%, 10%, and 15%) were prepared and their mechanical properties such as tensile, flexural, and impact were tested. It was found that tensile modulus had increased to 17% at 10% filler loading as compared to unfilled. These results were supported by scanning electron microscopy measurements of the fractured surface of the composites. All the fabricated composites resisted well against the chemicals and it indicates that the composites have excellent chemical resistance. The thermal properties were characterized by Thermogravimetric analysis which revealed that there was no improvement in thermal degradation temperature of the filled composites suggesting a way of thermally recycling the composites.

Effect of Alfa fiber mechanical separation on dielectric properties of hybrid unsaturated polyester composites

An exhaustive study of dielectric and impedance analysis on two Alfa‐fiber‐reinforced unsaturated polyester hybrid composites was performed. Alfa fiber reinforcements were hybridized by wool and PE/PET fibers in the relative volume fraction ratio 17:2:1. However, these reinforcements differ by the number of mechanical separation of Alfa fibers in the Shirley analyzer. For Composite (1), Alfa fibers were separated mechanically once in the Shirley analyzer whereas for the Composite (2), they were separated mechanically twice in the Shirley analyzer. Dielectric parameters analysis (, ) revealed the presence of the α‐relaxation process at intermediate temperature range for the matrix and the water dipoles polarization at low temperatures for the Composite (1). No dynamic dielectric relaxation was observed for the Composite (2) at low temperatures. However, dielectric properties were controlled by the dc conductivity effect at higher temperatures. The Kramers‐Kronig relation was used to eliminate its effect. Hence, α mode relaxation was observed for the matrix and the interfacial polarization effect was observed for its composites. The attenuated effect of this latter for the Composite (2) was attributed to its homogeneous structure. Electrical conductivity analysis using the Jonscher law allowed determining the transport mechanism for all studied materials and confirmed such result. Complex impedance analysis supported the homogeneous structure for the Composite (2). POLYM. COMPOS., 40:1774–1785, 2019. © 2018 Society of Plastics Engineers

Effect of Modification Time of Kenaf Bast Fiber with Maleic Anhydride on Tensile Properties of Kenaf-Glass Hybrid Fiber Unsaturated Polyester Composites

Natural fiber reinforced polymer composites are generally lower in mechanical performance compared to synthetic fiber reinforced polymer composites. However, this disadvantage can be improved via chemical modification of the natural fiber and hybridization with synthetic fiber. In this study, kenaf bast fiber was used as reinforcement in unsaturated polyester composites. It was subjected to chemical modification with maleic anhydride at various treatment time i.e. 60, 90 and 120 minutes prior to composites production. The untreated and MA treated kenaf bast fiber were hybridized with 10 weight percent of glass fiber to produce kenaf bast/glass fiber reinforced unsaturated polyester composites. The effect of treatment time on weight percent gain and functional group changes via infra-red spectra of kenaf bast fiber were investigated. The effect of treatment time on tensile properties of kenaf bast fiber and kenaf bast/glass fiber reinforced unsaturated polyester composites were also studied. It was revealed that the weight percent gain of kenaf bast fiber increased with the increasing of treatment time. The increasing of treatment time resulted in the enhancement of tensile strength and modulus of kenaf bast fiber and kenaf bast/glass fiber reinforced unsaturated polyester composites which were attributed to the presence of C=C bonds of maleic anhydride and has been proven through fourier transform infrared spectrum.

Mechanical Properties of Chicken Feather Reinforced Unsaturated Polyester Composites

In this paper, chicken feather fibers (CFFs) from poultry industries were used as reinforced materials incorporated with unsaturated polyester (UP) to create composites. It is prepared by varied the percentage weight fraction of CFFs by 2wt%, 4wt%, 6wt%, 8wt%, and 10wt%. Alkaline treated potassium hydroxide (KOH) was used to alter the structure of the CFFs. From the results it showed that the tensile strength of the CFFs/UP composites was reduced. The flexural modulus has optimum results of 35.3MPa, improved by 11.86% from pure UP (31.1MPa). For flexural modulus at 2wt% and 4wt% the untreated CFFs/UP performed better performance. However, started at 6wt% onwards, chemically treated fibers surpass untreated fiber. Even though CFFs has unique characteristics properties such as hollow honeycomb structure and low density, the poor adhesion due to its smooth surface roughness and uneven distribution of fiber during mixing contributed to the low strength and flexural values. Thus, treatment caused changes in the structure of the CFFs to increase the surface roughness of the fibers, which improve adhesion.

Effects of Rice Husk Derived Amorphous Silica on the Thermal-Mechanical Properties of Unsaturated Polyester Composites

ABSTRACTRice husk is rich in amorphous silica which has found various applications as a filler in rubbers and plastics. In the research described here silica was extracted from rice husk ash in the form of sodium silicate which was used to produced amorphous precipitated silica (PS) and silica aerogel (SA) using a sol – gel process and supercritical drying. These materials were then physically mixed with unsaturated polyester (UP) resin and cured at room temperature to form polymer composites. The experimental results showed that the UP composites with 30% (volume percent) of SA filler had lower density and better thermal insulation than the composites with the same amount of PS. Thermogravimetric analysis (TGA) results showed that the Tonset of the PS and SA composites were slightly delayed by 15 and 10°C, respectively. The tensile stress-strain curves showed that addition of the fillers reduced the tensile strength, but increased the elastic moduli of the UP matrix. PS filled UP composites exhibit higher moduli (higher stiffness) than that of SA filled UP composites. This was due to agglomeration and poor adhesion of the SA particles to the UP matrix while better dispersion was observed for the PS filled composite.

The application of 2D woven kenaf reinforced unsaturated polyester composite in automotive interiors

A 2D woven kenaf reinforced Unsaturated Polyester (UPE) has been successfully developed for pillar A and door panel for interior automotive parts. This study of woven kenaf fibers reinforced unsaturated polyester focused on application of 2D woven kenaf UPE for the purpose of automotive interiors parts. The reinforced preform selection was done based on the design with fixed and identified parameters. Plain weave design was selected as a reinforcement due to the stability and superior flexural and impact strength. Vacuum Infusion Process (VIP) was selected as a processing method to prepare the interior composite parts. Two different parts were selected in this study, which are pillar A and upper door panel, and the products show similar physical properties. The result indicates that the 2D woven kenaf UPE composite was proven capable to be applied as automotive interior parts.

Interfacially reinforced unsaturated polyester carbon fiber composites with a vinyl ester-carbon nanotubes sizing agent

A amino-functionalized carbon nanotubes (CNTs)-containing sizing agent was prepared for improving the interface bonding and impact toughness of carbon fibers (CFs) reinforced unsaturated polyester (UP) composites. More reactive groups and better interfacial compatibility with UP make vinyl resin M7270 a more suitable polymer for preparing sizing agent for CF/UP composites when compared to epoxy, MR13006 and R806. The surface characteristics of CFs and the interfacial properties of the composites before and after surface modification were investigated. The observed uniformly dispersed CNTs-containing sizing agent on the CF surface obviously increased the surface roughness. The amount of polar functional groups and the wettability of CFs were significantly enhanced after the coating treatment. The interlaminar shear strength (ILSS) and impact toughness were enhanced by 32.3 and 55.2%, respectively. The sizing agent effectively enhanced the interfacial adhesion by improving the surface energy, and increasing chemical bonding and mechanical interlocking.

Toughening of bamboo fibers/unsaturated polyester composites with 2‐acetoacetoxyethyl methacrylate

Bamboo fibers (BFs)‐reinforced unsaturated polyester (UPE) composites were prepared by hand lay‐up compression molding. The UPE resins were modified with 2‐acetoacetoxyethyl methacrylate (AAEM) and designed to improve the flexibility and toughness of the BFs–UPE composites. The results indicated that the toughness of the composites significantly increased as the AAEM usage increased. When compared with the untreated UPE composites, the composites obtained from AAEM modified UPE resins (with a 20:80 weight ratio of AAEM to UPE) had 21.7% higher impact strength. Dynamic mechanical analysis showed that incorporation of AAEM significantly increased the damping parameter and decreased glass transition temperature of the composites due to the introduction of flexible segments of AAEM into the UPE resins. Scanning electron microscopy images of the impact‐fractured surfaces of the composites revealed that AAEM modification improved the interfacial adhesion between BFs and UPE matrices. The main mechanism for the increase in the toughness of the composites could be due to the increased ductility of the matrices. POLYM. COMPOS., 40:1595–1601, 2019. © 2018 Society of Plastics Engineers

The Effect of Alkaline Treatment on the Mechanical Properties of Treated Sugar Palm Yarn Fibre Reinforced Unsaturated Polyester Composites Reinforced with Different Fibre loadings of Sugar Palm Fibre

The aim of this paper was to describe the effects of treated sugar palm yarn fibre loading on the mechanical properties of reinforced unsaturated polyester composites. Composites with varying fibre loads (10, 20, 30, 40 and 50 wt. %) were prepared using a hand-layup process. The composites were tested for tensile, flexural and impact strength according to ASTM D3930, ASTM D790 and ASTM D256 standards, respectively. The results showed that an increase in fibre loading of up to 30 wt. % increased tensile strength (31.27 MPa), tensile modulus (4.83 GPa), flexural strength (58.14 MPa) and modulus (4.48 GPa). Maximum loading can be attained at 40 wt. % of fibre loading for impact strength (38 kJ/ m2). The effectiveness of stress transfer mechanism through the fibre-matrix interaction, coupled with the optimization of fibre loading in resisting fracture and failure, boosts the overall mechanical performance of sugar palm composite.

Re‐Use of Marble Stone Powders in Producing Unsaturated Polyester Composites

The main goal of this study is to evaluate the potential of waste stone powders as filler in composite materials with a matrix of unsaturated polyester. These wastes are generated in the form of stone fragments and stone‐cutting sludge. Ground marble wastes are thoroughly characterized with the aim to use them as fillers: Mineralogical and chemical composition, particle size distribution, and morphology of these waste stone powders are investigated. Unsaturated polyester resin composites with the different stone powder fillers are prepared. The influence of powder type on the composites’ mechanical properties (tensile, bending, impact, and hardness characteristics), water resistance, thermal stability as well as surface fracture morphology of composites are studied. The moduli of the composites increase by 100%, the hardness of the composites may be improved by 80% upon loading with the “waste” filler, leading to an economical material and helping to reduce waste.

Development of sugar palm yarn/glass fibre reinforced unsaturated polyester hybrid composites

This study investigates the effect of fibre hybridization for sugar palm yarn fibre with glass fibre reinforced with unsaturated polyester composites. In this work, unsaturated polyester resin are reinforced with fibre at a ratio of 70:30 wt% and 60:40 wt%. The hybrid composites were characterized in terms of physical (density and water absorption), mechanical (tensile, flexural and compression) and thermal properties through thermal gravimetry analysis (TGA). Density determination showed that density increased with higher wt% of glass fibre. The inherently higher density of glass fibre increased the density of hybrid composite. Resistance to water absorption is improved upon the incorporation of glass fibre and the hybrid composites were found to reach equilibrium absorption at days 4 and 5. As for mechanical performance, the highest tensile strength, tensile modulus, flexural strength, flexural modulus and compression strength were obtained from 40 wt% of fibres reinforcement with ratio of 50:50 wt% of sugar palm yarn fibre and glass fibre reinforced unsaturated polyester composites. The increase of glass fibre loading had a synergistic effect on the mechanical properties to the composites structure due to its superior strength and modulus. The thermal stability of hybrid composites was improved by the increase of onset temperature and the reduction of residues upon increase in temperature.

Towards understanding the breakdown and mechanisms of glass fiber reinforced polyester composites in sub-critical water using some of the most employed and efficient additives from literature

This study describes the hydrolysis of glass fiber reinforced unsaturated polyester (UP) composites using some of the most employed and efficient additives from the literature. This includes the use of KOH, a mix of KOH/phenol and reference experiments without additives. Sub-critical water in a temperature range of 200–325 °C and a constant pressure of 300 bar were chosen as process parameters to cover a wide temperature range.It was possible to explain the mechanisms producing the majority of the different reaction products identified by GC-MS. The monomer phthalic anhydride was only recovered in the experiments without additives and was most stable at 200–250 °C. The increase or decrease in the production of monomers and other reaction products at different temperatures with and without additives has been clarified by the GC-MS investigations, which introduces new possibilities for tailoring the production of monomers and various chemical compounds via hydrolysis of polymer composites.

PREPARATION OF POLYMER COMPOSITES BASED ON UNSATURATED POLYESTER REINFORCED BY NATURAL FIBER AND CELLULOSE MICROFIBER FROM LUNG WASTE IN NGHE AN

Unsaturated polyester composites reinforced by glass fiber and by hybrid reinforcementglass fiber - lung fiber with cellulose microfiber (MFC) were prepared and investigated. Tensileand flexural strengths of material reached the highest value at polymer composite with 48 %wglass fiber mat and 0.3 %w MFC (208.33 MPa and 243.6 0 MPa), while the highest impactstrength reached 212.48 kJ/m2 at composite containing 48 %w glass fiber but 0.5 %w MFC.Especially, with 0.3 %w MFC, the tensile fatigue cycle to failure of composite processed byvacuum bag remarkably increased, 140.28 % at composite with 48 %w glass fiber and 265.63 %at hybrid composite reinforced by glass fiber/lung fiber, compared to samples without MFC.

Snail Shell as an Inspiring Engineering Material in Science and Technology Development: A Review

This review article provides a comprehensive overview of the research status on snail shells as inspiring engineering materials in Science and Technology development. Snail shells which represent the bio-shell waste of snails' remnants from restaurants, eateries or snail sellers constitute a serious degree of environmental threat with little or no economic value. Their effective utilization can bring immense economic prosperity. They are very useful raw materials in the treatment of waste water and the purification of aqueous solutions. They can also be used in the production of naturally based materials and for the preparation of calcium for medicinal purposes. Snail shells can be used as fillers in the paper industry to improve the paper capacity or in the cosmetic industries as face powder. Snail shells are suitable reinforcement materials for the production of composites applicable in the automotive components such as pistons, connecting rods and brake pads. Where flexural strength, hardness and impact strength are of paramount importance such as automobile parts, snail shells reinforced unsaturated polyester composites should be given priority. They are good alloying agents for aluminum based composites. The researches in this area are growing very fast, there is need therefore for continuous and upgraded review on this theme.

The Role of Bamboo Nanoparticles in Kenaf Fiber Reinforced Unsaturated Polyester Composites

The Role of Bamboo Nanoparticles in Kenaf Fiber Reinforced Unsaturated Polyester Composites

Development and Characterization of Hybrid Fibres Reinforced Composites Based on Glass and Kenaf Fibers

Composites are receiving an utmost importance in today’s scenario for their taylor made properties. Composites have a wide variety of applications in areas like aerospace, marine industry, automobiles and in engineering. They are considered because of their better mechanical properties. In a view to reduce the cost of production and the harmful destruction in normal environment, there's a extensive research have been conducted or still ongoing for the prospect of using natural fibers which are wholly degradable in the combination of biodegradable thermoplastic materials. This research will focus on Kenaf; an extremely valuable natural fiber with robust mechanical properties. In this research, kenaf fiber/fiber glass reinforced with unsaturated polyester composites were subjected to Flexural test and Tensile tests as per ASTM standards. A three point bending test was adopted to find the flexural strength of the prepared lamina. The test result shows that 8mm hybrid lamina has good flexural and tensile properties when compared to other lamina.

Bulk/nano-mechanical and tribological response of functionalised multi-wall carbon nanotubes reinforced unsaturated polyester composites

The study concerns the bulk flexural, wear and nano-mechanical properties of nanotube dispersed unsaturated polyester composites with different amounts of nanotubes content. The results demonstrate the variation of bulk and nano-mechanical properties with nanotube weight fractions. Functionalisation MWCNT has yielded improved dispersion and enhanced mechanical properties. This has been attributed to the reduced agglomeration tendency of the nanofillers achieved appropriate functionalisation of the filler surface.