Polyester Resin (polyester + resin)

Distribution by Scientific Domains

Kinds of Polyester Resin

  • unsaturated polyester resin


  • Selected Abstracts


    Amine Modifiers with an s-Triazine Ring for Unsaturated Polyester Resins, 2,

    MACROMOLECULAR MATERIALS & ENGINEERING, Issue 10-11 2007
    Mono-, Multihydroxyalkyl Modifiers
    Abstract The paper deals with the synthesis of amine modifiers for unsaturated polyester resins obtained from N -phenyl-2-amineethanol and 2,4-dichloro-6-methoxy-1,3,5-triazine (modifier A), 2-chloro-4,6-dimethoxy-1,3,5-triazine (modifier B) or with cyanuric chloride (modifier C). Properties of amine modifiers for unsaturated polyester resins are presented. The modifiers were incorporated into resins at the polycondensation stage. [source]


    Biofilm Growth and Bed Fluidization in a Fluidized Bed Reactor Packed with Support Materials of Low Density,

    ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 2 2004
    R.A. Saucedo-Terán
    Abstract Support materials of low-density for fluidized bed reactors provide several operational advantages, including lower energy requirements and proper biofilm growth balance. The aim of this investigation was to study the extent of biofilm growth and bed fluidization in an experimental reactor, using polyester resin (,pr,=,1220,kg/m3) and vitrified expanded perlite (,vep,=,1710,kg/m3) as alternative support materials to conventional silica sand. A noteworthy amount of biofilm was observed to be attached to both support materials from the very beginning of the bioreactor operation. Nevertheless, there were significant variations in biofilm growth and activity over the course of the experimental trials. For both perlite and polyester beds, the highest biofilm mass and the highest total number of mesophilic bacteria were observed between the 7th and the 10th day, showing a steady state trend at the end of the experimental runs. The chemical oxygen demand (COD) removal levels were concomitant with biofilm mass and total mesophilic bacteria changes, although the polyester bed efficiency was slightly higher than that for the perlite bed. As expected, the polyester bed was fluidized at a lower re-circulation flow compared to the perlite bed. Reactor back-washing was not required for these support materials since biomass excess was adequately separated by means of a special internal device. The efficiencies of removal of organic matter achieved were acceptable (up to 78,%) despite the low volume of the support material (25,%) and the low hydraulic retention time (30,min). [source]


    Compatibilization and development of layered silicate nanocomposites based of unsatured polyester resin and customized intercalation agent

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010
    Luigi Torre
    Abstract In this study a procedure for the preparation of compatibilized nanoclays was used to produce effective nanocomposites based on unsatured polyester (UP) resin. A compatibilization procedure of the filler with a selected surfactant has been developed and optimized, the effect of organic modifiers on the synthesized nanocomposites properties was studied. Moreover, polyester/clay nanocomposites were prepared. In particular, samples were prepared using two different mixing methods. The properties and formation processes of the nanocomposites obtained using the two methods were compared. X-ray diffraction studies revealed the formation of intercalated/exfoliated nanocomposites structures. The effect of processing parameters, used for both the compatibilization procedure and the preparation of nanocomposites, was studied. Dynamic mechanical, thermal analysis, and rheological tests were performed to investigate the formation mechanism of UP/montmorillonite nanocomposite. In particular, mechanical properties of nanocomposites were studied using dynamic mechanical analysis and tensile tests. Mechanical, rheological, and thermal characterization have confirmed the validity of the used approach to compatibilize the nanoclay and to produce nanocomposites. Tensile strength and Young's modulus were modified by the loading of the organoclays. Furthermore, the rheology of the nanocomposite formulation provided processing information, while mechanical and dynamic mechanical characterization was performed on the nanocomposites produced with the newly compatibilized formulation. The results have shown that nanocomposites with better mechanical properties can be obtained through the selection of an appropriate compatibilization process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]


    Investigation of flame retardancy and physical,mechanical properties of zinc borate/boric acid polyester composites

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010
    Miyaser Demirel
    Abstract The glass fiber reinforced polyester composite materials were prepared with varying contents of boric acid, zinc borate, and magnesium hydroxide as flame retardants to improve the flame retardancy of the composites. Experimental results showed that boric acid exhibited a good flame retardant effect on the polyester composite. When boric acid content is used as 15 wt %, the Limiting Oxygen Index (LOI) value of the composite reached upto 25.3. The increase in boric acid content from 15 to 30 wt %, the LOI values of composite were enhanced from 25.3 to 34.5 by 9.2 units. The LOI values of the composite samples increased with increasing boric acid content. The smoke density results showed that the addition of glass fiber and flame retardants decreased the smoke density of the unreinforced polyester resin. The mechanical properties of the composites have decreased by the addition of flame retardants. The scanning electron micrographs taken from fracture surfaces were examined. The flame retardants, such as boric acid, were well dispersed in the glass fiber reinforced polyester composites and obviously improved the interfacial interaction between glass fibers and polyester composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]


    Novel polyurethane elastomer continuous carbon fiber composites: Preparation and characterization

    JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007
    Borda
    Abstract Preparation and characterization of novel polyurethane (PUR),carbon fiber (CF) composites are reported. The reinforcement of PUR elastomers was achieved using unidirectional continuous CFs with different coatings (uncoated and epoxy and polyester resin coatings) by applying molding for the preparation of PUR-CF composites. Considerable reinforcement of PUR was attained even at relatively low CF content, e.g., maximum stress and Young's modulus of PUR-CF composite at CF content 3% (m/m) were found to be 3,5 and 4,10 times higher than those of the PUR-matrix, respectively. In addition, a linear relationship between the Young's modulus and the CF content was found as well as linear variation of maximum stress with the CF content was also observed. The adhesion of CF to the PUR-matrix was strong in each case as concluded from the strain,stress and the scanning electron microscopy (SEM) investigations. However, the extent of reinforcement of PUR at a given CF content was found to depend greatly on the coatings of CF, and increased in the following order: epoxy resin < polyester resin < uncoated. The effect of the coating of CF on the reinforcement of PUR is also discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 287,292, 2007 [source]


    Impact damage detection and degradation monitoring of wet GFRP composites using noncontact ultrasonics

    POLYMER COMPOSITES, Issue 8 2009
    K. Berketis
    Two different non-crimp glass fabrics with a polyester resin were used to produce laminated plates that were subjected to low velocity impact testing using three impact energy levels. The plates were immersed in water at 65°C for up to 24 months. The effectiveness of a traditional water coupled and an air-coupled ultrasonic C-Scan system was assessed in terms of damage size evaluation at various time intervals. The conditioned impacted plates were retested statically in compression to determine the residual strength for evaluation of damage tolerance. Weight change measurements revealed an initial increase due to water diffusion, followed by an extended decrease due to matrix dissolution at long-term immersion times. The use of water coupled pulse-echo ultrasonics proved ineffective after long-term water immersion as damaged areas became ultrasound-invisible. The contrast between impact damaged areas and water diffused areas was restored with the air-coupled C-scan. The macroscopic damage size was not affected by the long-term water immersion and the overall weight change while the residual compression strength was seemed to be dependent on the time of immersion and the size of the pre-existing impact damage. Calibrating the air-coupled system to a dry condition specimen, a good qualitative and quantitative indication of the degraded state of water immersed plates was obtained. This monitoring system for the degradation process seems to be very promising. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source]


    Polyester composites reinforced with noncrimp stitched glass fabrics: Experimental characterization of composites and investigation on the interaction between glass fiber and polyester matrix

    POLYMER COMPOSITES, Issue 3 2008
    Volkan Cecen
    The primary purpose of the study was to investigate the anisotropic behavior of different noncrimp stitched fabric reinforced polyester composites. The effects of geometric variables on composite structural integrity and strength are illustrated. Hence, tensile, three-point bending flexural and short beam shear tests were conducted up to failure on specimens strengthened with different layouts of fibrous plies in noncrimp stitched fabric. The remark, based on the observations while tensile testing, is that the stress,strain curves of polyester based composites were linear in the direction of fibers. However, in the matrix dominated orientations nonlinear relation between the stress and the strain was observed. Another aim of the present work was to investigate the interaction between glass fiber and polyester matrix. The experiments, in conjunction with scanning electron photomicrographs of fractured surfaces of composites, were interpreted in an attempt to explain the interaction between glass fiber and polyester and were interpreted in an attempt to explain the instability of polyester resin,glass fiber interfaces. It was concluded that the polymer was either deposited between adjacent fibers or as widely separated islands on the fiber surface. Infrared spectra of the cured polyester and its glass fiber composite were obtained by Fourier transform infrared spectroscopy. POLYM. COMPOS., 2008. © 2007 Society of Plastics Engineers [source]


    The effect of biological studies of polyester composites filled carbon black and activated carbon from bamboo (Gigantochloa scortechinii)

    POLYMER COMPOSITES, Issue 1 2007
    H.P.S. Abdul Khalil
    The development of composites using various filler material increased significantly nowadays. Composite materials need to implement the biological and mechanicals impact in their life cycle. The carbon black (CB) and activated carbon (AC) from bamboo (Gigantochloa scortechinii) were used as filler in polyester composites. CB and AC were pyrolized to 700°C and activated with ZnCl2. The composites were prepared with 40% filler loading. The degradation of the composites CB and AC (mechanical properties) to the soil burial test was determined. Tensile, flexural, impact and mass changes of the buried samples were investigated. The deterioration of the samples affected by the biological attack was confirmed by SEM studies. The assessment was done after 0, 3, 6, and 12 months of the biological exposure and the results were compared with the composites filled CaCO3 (commercial filler) and cast polyester resin (as control). POLYM. COMPOS. 28:6,14, 2007. © 2007 Society of Plastics Engineers [source]


    Temperature dependence of electrical resistivity in carbon nanofiber/unsaturated polyester nanocomposites

    POLYMER ENGINEERING & SCIENCE, Issue 7 2008
    Toshiaki Natsuki
    This article described the temperature dependence of electrical resistivity for carbon nanofiber (CNF)/unsaturated polyester resin (UPR) nanocomposites prepared by a solvent evaporation method. It was found that the CNF/UPR nanocomposites had quite low electrical percolation threshold due to CNFs having a large aspect ratio and being well dispersed into the UPR matrix. A sharp decrease in the electrical resistivity was observed at about 1 wt% CNF content. The influence of CNF content on the electrical resistivity was investigated as a function of temperature in detail. The nanocomposites showed a positive temperature coefficient effect for the resistivity, and had a strong temperature dependence near the percolation threshold. When the number of thermal cycles was increased, the electrical resistivity decreased and had a weak temperature dependence, especially in the case of melting temperature. Moreover, the size influences of CNFs on the electrical properties of nanocomposites were analyzed and discussed. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source]


    Processability studies of silica-thermoset polymer matrix nanocomposites

    POLYMER ENGINEERING & SCIENCE, Issue 2 2008
    C. Lekakou
    The aim of this study is to investigate the processability of silica-thermoset polymer matrix nanocomposites in terms of dispersion of silica nanoparticles and their effect on curing. Two thermosetting resins were considered, an epoxy and a polyester resin, with 5% silica, although 1% silica was also used in preliminary studies in the polyester system. Various combinations of mechanical mixing and sonication were investigated for the dispersion of silica nanoparticles under different processing conditions and times in solvent-free and solvent-containing systems. It was found that the best dispersion route involved a solvent-aided dispersion technique. Consequently, different procedures for the solvent removal were investigated. Optical microscopy and SEM were used to characterize the resulting nanocomposites. DSC and rheological DMTA tests demonstrated that the silica nanoparticles shorten the gel time and promote curing in these thermosetting systems. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers [source]


    Composites from PMMA modified thermosets and chemically treated woodflour

    POLYMER ENGINEERING & SCIENCE, Issue 5 2003
    Betiana A. Acha
    The mechanical behavior of composites made from woodflour and a modified thermoset unsaturated polyester resin has been examined. Polymethylmethacrylate (PMMA), a common low profile additive (LPA), was used as the matrix modifier. Woodflour, the reinforcing filler, was used ,as received' and was also modified with a commercial alkenyl succinic anhydride (ASA), in order to enhance the compatibility with the resin. The composites exhibited higher flexural and compressive modulus and compressive yield stress than the neat resin, while flexural strength and ultimate strain were reduced. The addition of PMMA to the unfilled thermoset led to a LPA morphology and decreased the flexural modulus, but produced an increment in flexural strain at break, impact energy and toughness of the UP resin. No enhancement in the mechanical behavior of the composites was found when treated woodflour instead of unmodified woodflour was used. [source]


    Percolation phenomena in carbon black,filled polymeric concrete

    POLYMER ENGINEERING & SCIENCE, Issue 9 2000
    L. Rejón
    Percolation in carbon black-filled polymeric concrete, is discussed based on the measured changes in electrical conductivity and morphology of the composite at different concentrations of carbon black. The percolation threshold ranged between 6 and 7 wt% (based on resin weight) of carbon black. Above this concentration, the filler particles formed agglomerates in contact with each other, suggesting that the conduction process is nearly ohmic in nature. A power law predicted by percolation theory described the behavior of the conductivity as a function of carbon black content. Microscopic analysis showed the presence of a continuous structure formed by the polyester resin and carbon black, in which silica particles were embedded. [source]


    Intraply and interply hybrid composites based on E-glass and poly(vinyl alcohol) woven fabrics: tensile and impact properties

    POLYMER INTERNATIONAL, Issue 9 2004
    Prof Alessandro Pegoretti
    Abstract E-glass and poly(vinyl alcohol) (PVA) fibres were used to produce both homogeneous and hybrid composites with an orthophthalic unsatured polyester resin. Results are presented regarding the tensile and impact behaviour of both intraply and interply hybrid composites, with particular regard to the effects of the plies stacking sequence and the loading direction. With a proper choice of composition and stacking sequence, E-glass/PVA hybrid composites were proved to achieve a property profile superior to those of homogeneous E-glass laminates in terms of specific properties. In particular, hybridization with PVA fibres resulted in improving the specific impact energy of E-glass laminates. Resistance to impact crack propagation was higher for intraply with respect to interply hybrid composites, as evidenced by their ductility index values. Copyright © 2004 Society of Chemical Industry [source]


    Occupational allergic contact dermatitis to cobalt octoate included as an accelerator in a polyester resin

    AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 2 2006
    Namrata S Anavekar
    SUMMARY A 46-year-old woman, who worked as a laminator of spa baths, presented with hand dermatitis, which was suspected to be related to her occupation. Patch testing revealed strong reactions to both cobalt chloride and a polyester resin that the patient had been using at her workplace. She also reacted to latex and had been wearing cotton gloves underneath rubber gloves at work. It was later discovered that cobalt octoate (synonym: cobalt-2-ethylhexanoate), a compound not listed on the manufacturer's material safety data sheet, was included as an accelerator in the polyester resin. She was then tested to cobalt octoate, which was also strongly positive. Her successful treatment included protection of her hands at work with cotton lined PVC gloves. This case highlights the role of cobalt salts as sensitizers and their presence as accelerators used in polyester resins, and the importance of recognizing concomitant latex allergy that may complicate occupational dermatitis. It also illustrates the difficulties in relying on material safety data sheets to identify all possible allergens. [source]


    Amine Modifiers with an s-Triazine Ring for Unsaturated Polyester Resins, 2,

    MACROMOLECULAR MATERIALS & ENGINEERING, Issue 10-11 2007
    Mono-, Multihydroxyalkyl Modifiers
    Abstract The paper deals with the synthesis of amine modifiers for unsaturated polyester resins obtained from N -phenyl-2-amineethanol and 2,4-dichloro-6-methoxy-1,3,5-triazine (modifier A), 2-chloro-4,6-dimethoxy-1,3,5-triazine (modifier B) or with cyanuric chloride (modifier C). Properties of amine modifiers for unsaturated polyester resins are presented. The modifiers were incorporated into resins at the polycondensation stage. [source]


    Radiation and postirradiation crosslinking and structure of two unsaturated polyester resins

    POLYMER ENGINEERING & SCIENCE, Issue 9 2008
    Irina Puci
    Radiation and postirradiation crosslinking of two unsaturated polyester (UP) resins were monitored, and substantial differences in the reaction course and extents were observed. DSC thermograms of one of the resins showed double peaks and significantly lower residual reaction heats. Extraction revealed that gelation dose of the resin with double peak was twice the gelation dose of the other resin that had single peak in DSC thermograms. Although other components of the polyesters were identical, NMR spectra of the resin with a single peak revealed isophthalic units while in the polyester of the resin having double DSC peaks orthophthalic units were detected. Orthophthalate reduced the compatibility of polyester and styrene and caused the reaction-induced phase separation, influencing gel structure that was visible in scanning electron microscope micrographs. Previously, the double peaks in crosslinking thermograms of UP resins were usually attributed to initiator effects, but here no initiator was used, and, in the literature, we found that the double peaks are almost exclusively present in the thermograms of UP resins containing orthophthalates, whereas in resins with isophthalates double peaks almost never appear. Crosslinking extents were significantly higher in the resin-containing isophthalate and in both cases enhanced by postirradiation reaction that is often neglected. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source]


    Thermal degradation of a brominated bisphenol a derivative

    POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 11-12 2003
    M. P. Luda
    Abstract The thermal degradation of 2,6,2,,6,,tetrabromo-4,4,-isopropylidene-di phenol (tetrabromobisphenol A) (TBBPA) has been investigated and a mechanism for its thermal degradation is suggested. TBBPA is a comonomer widely used in epoxy and in unsaturated polyester resins to impart fire retardance. These resins find a common use in electric and electronic equipment. The presence of bromine atoms is the key factor in fire retardant activity, while on the other hand it represents an ecological problem when pyrolytic recycling is programmed at the end of the useful life of such items. However, pyrolysis is the more advantageous recycling system for thermosetting resins and thus efforts should be made to control the pyrolysis in order to avoid or minimize the development of toxics. Homolytic scission of the aromatic bromine and condensation of aromatic bromine with phenolic hydroxyl are the main processes occurring in the range 270,340°C. A large amount of charred residue is left as a consequence of condensation reactions. HBr and brominated phenols and bisphenols are the main volatile products formed. Brominated dibenzodioxins structures are included in the charred residue and not evolved in the volatile phases. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Occupational allergic contact dermatitis to cobalt octoate included as an accelerator in a polyester resin

    AUSTRALASIAN JOURNAL OF DERMATOLOGY, Issue 2 2006
    Namrata S Anavekar
    SUMMARY A 46-year-old woman, who worked as a laminator of spa baths, presented with hand dermatitis, which was suspected to be related to her occupation. Patch testing revealed strong reactions to both cobalt chloride and a polyester resin that the patient had been using at her workplace. She also reacted to latex and had been wearing cotton gloves underneath rubber gloves at work. It was later discovered that cobalt octoate (synonym: cobalt-2-ethylhexanoate), a compound not listed on the manufacturer's material safety data sheet, was included as an accelerator in the polyester resin. She was then tested to cobalt octoate, which was also strongly positive. Her successful treatment included protection of her hands at work with cotton lined PVC gloves. This case highlights the role of cobalt salts as sensitizers and their presence as accelerators used in polyester resins, and the importance of recognizing concomitant latex allergy that may complicate occupational dermatitis. It also illustrates the difficulties in relying on material safety data sheets to identify all possible allergens. [source]