Increasing Resin Content Research Articles

Foam sandwich composites with cyanate ester based syntactic foam as core and carbon‐cyanate ester as skin: Processing and properties

AbstractFoam sandwich composites were processed using cyanate ester‐based syntactic foam as core and carbon fabric‐cyanate ester composite as skin. They were processed by a one‐step compression‐molding technique. The mechanical performance of the sandwich composites was evaluated in terms of flatwise tensile strength (FTS), flatwise compressive strength, and edgewise compressive strength. The dependency of these properties on the core composition was investigated. FTS initially increased with the increase in resin content of the syntactic foam core. However, higher resin content in the core led to a diminution in FTS due to high void content. The flatwise compressive strength and edgewise compressive strength and the corresponding moduli values showed an increasing trend with increase in resin content of the core despite the presence of voids at high resin content. The failure modes of the composites under different loading conditions have been examined. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Mechanical properties of polymer concrete made with recycled PET and recycled concrete aggregates

The purpose of this study was to solve some of the solid waste problems posed by plastics and concrete demolition. To this end, we evaluated the mechanical properties of polymer concrete, in particular, polymer concrete made of unsaturated polyester resins from recycled polyethylene terephthalate (PET) plastic waste and recycled concrete aggregates. The strength and the resistances to acid and alkali compounds of the polymer concrete were measured by varying the coarse and fine aggregate ratio and resin content. Three main observations followed the results. First, we found that the strength of polymer concrete made with a resin based on recycled PET and recycled aggregate increases with increasing resin content; however, beyond a certain resin content, the strength does not change appreciably. Second, the stress–strain curves of polymer concretes with 100% natural aggregate and 100% recycled aggregate exhibited different failure mechanisms of the compressed materials. Third, with respect to acid resistance, the polymer concrete at a resin content of 9% was nearly unaffected by HCl, whereas the polymer concrete with 100% recycled aggregate showed poor acid resistance. Unlike acid, alkali compounds did not seem to attack the polymer concrete with 100% recycled aggregate as observed from the weight change and the compressive strength.

Wear Properties of Basalt Fibers Reinforced Composites

Compared to traditional fiberglass, basalt fibers have a wide spectrum of applications used as textile fiber or reinforcement for composites. Epoxy resin composites filled with basalt fibers were prepared by proper curing, using KH-550 silane coupling agent to enhance the interfacial bonding between the inorganic reinforcing agent and the polymer matrix. The milling abrasive wear was investigated in slurry containing sand abrasive particles using milling equipment. The experimental results indicated that basalt fibers, EP and the nano-sized SiO2 filling formed steady composites. The wear rate of the sample was reduced with the increase of resin content before the content of resin amounted to 40%. When the content of resin is more than 40%, the wear rate of the sample deceased slightly.

Shear Strength of SMR—Based Pressure-Sensitive Adhesives

The shear strength of Standard Malaysian Rubber (SMR)-based pressure-sensitive adhesives was studied using coumarone-indene resin as the tackifier resin. Three grades of SMR, i.e., SMR L, SMR 10, and SMR 20 were used as the elastomers. The concentration of tackifier resin was varied from 0–80 parts per hundred parts of rubber (phr). Toluene was used as the solvent throughout the experiment to prepare the pressure-sensitive adhesives. A SHEEN hand coater was used to coat the adhesive on the polyethylene terephthalate substrate to give a coating thickness of 30, 60, 90, and 120 µm. Shear strength of the adhesive was determined by using a Texture Analyzer. Results indicate that for a fixed coating thickness, shear strength decreases gradually with increasing resin content for all the rubbers studied. This observation is attributed to the decreasing cohesive strength of adhesive as resin loading is increased. However, for fixed resin content, shear strength increases with increasing coating thickness suggesting that shear strength is thickness-dependent. SMR L consistently shows higher shear strength than SMR 10 and SMR 20 for all coating thickness, an observation, which is attributed to higher purity of SMR L, compared with the latter two rubbers. The shear strength passes through a maximum at 5 min of mastication time, after which it decreases gradually with further mastication.

The low-pressure infiltration of diamond by silicon to form diamond–silicon carbide composites

The infiltration of fine-grained diamond preforms by molten silicon is limited by the blocking of the pores as a result of the volume increase during the reaction of diamond with SiC. Therefore in the present paper the infiltration of preforms made with diamond powders with different grain sizes was investigated. The preforms were prepared using phenolic resin as a binder. With increasing resin content the pore size increases, but the pore volume decreases. As a result the infiltration depth increases strongly for medium resin content. For the fine-grained ∼1.5 μm diamond preforms, a maximum infiltration depth of 2.5 mm is obtained at 10% resin, whereas at 5% resin only 1.25 mm could be infiltrated.

Bending and Bonding Properties of Sandwiched Polymer Concrete Composites

It is foreseen that the properties of Polymer Concrete (PC) can be further enhanced if the PC is bonded to or sandwiched between Glass Fibre Reinforced Plastic (GFRP) laminates, later termed as PC-GFRP system. In the present investigation, the performance of PC-GFRP was assessed in terms of its bending strength and bonding strength between PC and GFRP. Panels of PC size 500 mm × 500 mm × 20 mm were prepared. The panels then were cut into specimens of appropriate geometry and dimensions required for the tests. Four (4) different resin contents and different percentages of aggregate of different particle size distributions were employed in preparing the PC-GFRP specimens. A batch of PC specimens was layered with a Glass Fibre Reinforced Plastic (GFRP) laminate on one side (SSL) and the other batch PC specimens were sandwiched with two GFRP laminates (DSL). The PC-GFRP specimens were tested their bending strength under three-point load test and bonding strength between PC as a core material and glued GFRP laminate(s). The results showed that an increase in the resin content increases the bending strength of the PC regardless of the aggregate grading. The results also revealed that the PC specimens with well-graded aggregate recorded the highest bending strength, with coarser grading resulted in further increase. The bending strength of the PC-GFRP system improved significantly when the PC was externally reinforced with a GFRP laminate (SSL) but did not improve further when another layer of GFRP laminate was applied (DSL). The bonding strength between PC and GFRP was found to be increased as the resin content increases and the GFRP laminate bonded better to the PC as a core material if made of the overall aggregate size.

Viscosity and Peel Strength of SMR 10-Based Pressure-Sensitive Adhesives

The viscosity and peel strength of a natural rubber-based pressure-sensitive adhesive was studied. One grade of natural rubber (SMR 10) and coumarone-indene resin were used as the elastomeric material and tackifier, respectively. Throughout the experiment, toluene was used as the solvent to prepare the adhesive. The effect of mastication time of rubber and tackifier concentration on the viscosity and peel strength of adhesive on various substrates was systematically investigated. The viscosity was measured using a HAAKE Rotary Viscometer. T-Test, 90° Adhesion To Steel (ATS), and 180° Adhesion To Steel (ATS) Tests were used to determine the peel strength of the adhesive. The results indicate that the viscosity of the adhesive increases with the resin content but decreases with mastication time. The peel strength generally increases with an increase in resin content except for the 20 min masticated sample. For all concentrations of the resin tackifier studied, the 10 min masticated sample exhibits the highest peel strength as compared to the corresponding values of the other masticated samples. This observation is attributed to the optimum wetting and formation of mechanical interlocking, and anchorage of the adhesive in pores and irregularities in the substrate for the former sample.

USING QUERCUS INFECTORIA GALL NUT TANNIN AS A BINDER INPARTICLEBOARDS PRODUCTION

Adhesives derived from oak (Quercus infectoria) galls tannin and urea-formaldehyde were used to produce particleboards of 18 mm. thickness from pinewood particles at 8 and 12% resin content and target density of 0.60 gm / cm3. Five levels of blending ratios were followed namely; 100 TF:0 UF, 75 TF:25 UF, 50 TF:50 UF, 25 TF:75 UF, and O TF:100 UF. The physical and mechanical properties of the produced panels were tested after conditioning according to ASTM standard D-1073. The results indicated, that tannin from oak galls has good potential for use as adhesive. It has been shown from the results that incorporating urea-formaldehyde with tannin-formaldehyde produced good quality adhesive for the manufacture of particleboard for interior use. An increase in the levels of urea in the adhesive blends caused an increase in panels strength such as MOR, MOE, and IB, while WA and Th.S. decreased by increasing levels of tannin-formaldehyde. The increase in resin content of all produced panels improved all particleboard properties.

Development of charged ion exchange resin-polymer ultrafiltration membranes to reduce organic fouling

This work deals with the performance of polymeric membranes charged with an ion exchange resin on the ultrafiltration (UF) of an oily suspension. The membranes were prepared by the phase inversion process from polysulfone (PSf) solutions and different percentages of resin. The structural and functional study of membranes was carried out by SEM, dextran rejection, streaming potential (SP), oil content and chemical oxygen demand (COD). The structural study showed that there is an important change of the porous membrane substructures leading to a higher densification when the resin content increases. The results showed that the membrane propensity fouling decreased with increasing resin concentration (1–20 wt.% resin). The best performance—less membrane fouling and better permeate quality—was obtained with the membrane prepared with 20 wt.% resin.

일축 하중을 받는 PET 재활용 폴리머콘크리트의 응력-변형률 모델의 제안

Polymer concrete shows excellent mechanical properties and chemical resistance compared with conventional normal cement concrete. The polymer concrete is drawing a strong interest as high-performance materials in the construction industry. Resins using recycled PET offer the possibility of a lower source cost of materials for making useful polymer concrete products. Also the recycling of PET in polymer concrete would help solve some of the solid waste problems posed by plastics and save energy. The purposed of this paper is to propose the model for the stress-strain relation of recycled-PET polymer concrete at monotonic uniaxial compression and is to investigate for the stress-strain behavior characteristics of recycled-PET polymer concrete with different variables(strength, resin contents, curing conditions, addition of silane and ages). The maximum stress and strain of recycled-PET polymer concrete was found to increase with an increase in resin content, however, it decreased beyond a particular level of resin content. A ascending and descending branch of stress-strain curve represented more sharply at high temperature curing more than normal temperature curing. Addition of silane increases compressive strength and postpeak ductility. In addition, results show that the proposed model accurately predicts the stress-strain relation of recycled-PET polymer concrete

木質材料 針葉樹バークを原料としたブロック状成形物の製造と材質評価

A composite made from bark, named bark-block, was developed to promote utilization of the bark residue. Airdried bark of Japanese conifers (sugi and hinoki) was used as furnish. The bark-block with dimensions of 400mm by 400mm by 55mm was fabricated using urethane resin as a binder. Steam was injected during pressing through holes on the press platen. Target density of this composite was 0.4g/cm3. A small-scale production machine that can be installed in a local sawmill or a logging site was designed for this purpose. The effect of manufacturing parameters on the properties of the bark-block was investigated to obtain the optimum conditions. The experimental results showed that bending properties (MOR and MOE), compressive stiffness, and IB strength increased with increasing resin content. Mechanical properties were proved to be controlled by the amount of the resin applied. It was found that the preferable steam injecting time for resin curing was 3 minutes. Thickness swelling was from 5 to 10 percent after water immersion treatment, while the water absorption was more than 80 percent. The bark-block produced have started to be used as a paving material in a park or in an exposition.

Influence of resin content and compaction pressure on the mechanical properties of SiC–Si composites with sub-micron SiC microstructures

Abstract The influence of resin content (15–20, 25 wt.%) and compaction pressure (75, 100, 125 MPa) on the mechanical properties and microstructure of SiC–Si composites with sub-micron microstructure has been evaluated. To produce the composites three powders with particle sizes in the range of 0.22–0.70 μm were used. Before application the SiC powders were treated with hydrofluoric acid to remove the extent of SiO2. Due to this treatment a successful infiltration of green-bodies, even of those produced of SiC powder with a mean particle size of 0.22 μm, was possible. The fracture toughness and bending strength increased with increasing resin content. The highest value of strength was observed at 733 MPa for the composites produced of SiC powder with a mean grain size of 0.70 μm and a resin content of 25 wt.%. Within this composite the free silicon content was reduced to 12 vol.%. In regard to previous experiments this is a reduction of more than 50%. These results are a consequence of the lowering of the free silicon content of the composites when increasing the resin amount. With decreasing SiC starting particle size the mechanical properties decreased but they were independent on compaction pressure.

Water swellability and tensile properties of plasticized cured gelatin-trimethylolphenol blends

Gelatin has been chemically modified by crosslinking with timethylolphenol (TMP), which represents the smallest molecule of the phelol-formaldehyde resins, and exhibits high reactivity towards gelatin. Although gelatin is soluble in water in all proportion, the cured gelatin–TMP blends only swell in water, swellability decreasing with increasing resin content. They exhibit moderate tensile strength, but very low elongation at break. Elongation is substantially improved by using a polyethylene glycol, PEG 400, as cosubstrate to gelatin, which serves as a plasticizer. Binding efficiency of PEG 400 to the cured blend network, and the water swellability and tensile properties of the cured plasticized blends have been reported. Some practical advantages and possible areas of application have also been highlighted. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1721–1729, 1999

木質材料 パーティクルボードの寸法安定性に及ぼす製造因子の影響

The object of this study was to investigate the dimensional stability (DS) for particleboards (PBs) made by changing factors of board preparation, this is, density of boards, resin content, adhesives, particle size and wood species. The measurement of moisture absorption, in-plane linear expansion (LE) and thickness swelling (TS) were done to evaluate DS of PBs.The results are summarized as follows: It was clear that the values of LE and TS were decreased with decreasing density of boards and increasing resin content. DS of adhesives used was superior in order of phenolic resin (PF)>Isocyanate resin (IC)>Urea resin (UF). The oriented boards prepared from birch and Hinoki showed excellent resistance against moisture absorption, and anti-swelling efficiency on their LE values (L-ASE) in 50% and 35%, respectively.

Effect of manufacturing parameters on the linear expansion and density profile of particleboard

Particleboards were fabricated in the laboratory with different board densities and resin contents to evaluate linear expansion when exposed to both vapor and liquid water. Density profiles were measured to determine the relation to the elastic constants and to the dimensional properties of the boards. It was found that density profiles were affected by the board density and resin content applied. The high-density layer formed in the thickness direction affected the elastic constant measurements. A model introduced to predict the linear expansion closely matched the data during exposure to water. Under conditions of 40°C and 90% humidity, linear expansion increased with increasing board density. An increase in resin content from 6% to 12% slightly increased the linear expansion and decreased the thickness swelling. A linear relation was found between board density and linear expansion per unit of moisture content change.

Polyurethane Solvent-Based Adhesives for Footwear Applications

Polyurethane solvent-based adhesives with and without tackifier having different solid contents were prepared. Viscosity of adhesives was found to increase with increasing resin content. Peel strengths of adhesives before and after aging were measured on PVC-Leather substrates and TPR-Leather substrates. It is found that the tackifier improves the adhesive strength of the polyurethane. In the case of TPR-Leather substrates all adhesives give good performance immediately on application of adhesive whereas in the case of PVC-Leather substrates good results are achieved only after 24 hrs of application. Shelf-life of the adhesives is found to be 6 to 12 months.

木質材料 木粉を原料としたボードの製造と材質に関する研究

Wood-based boards were manufactured under heat and pressure using softwood powder of #100 in size as furnish bonded by a novolac type of phenol-formaldehyde powder resin. The bending properties, internal bond strength and dimensional stability were determined to evaluate the effects of the specific gravity (SG), resin content (RC) of the board and platen temperature at pressing. The results obtained were summarized as follows:(1) After a rapid temperature rise during pressing, the core temperature of the mat showed the plateau stage around 140°C for all the press conditions in this experiment ranged from 160°C to 220°C. (2) The bending properties, modulus of rupture and modulus of elasticity increased linearly with increasing resin content up to about 20% and leveled off above 30% RC. A linear relationship was found between bending properties and SG of the board. (3) It was found that the boards made from the wood powder can have higher internal bond strength compared with that of particleboards. (4) The boards with 15% resin content or more showed a fairly good dimensional stability against the water soaking treatment.

The influence of curing systems on the properties of bromobutyl rubber: Part 2—Effect of concentration of curing resin on the dynamic mechanical properties

Measurements of isochronal dynamic mechanical properties of cured, uncured and thermally aged rubber vulcanizates have been carried out using a Rheovibron DDV-III-EP elasticoviscosity meter as a function of temperature between −150°C and +250°C. The effects of curing resin (phenol/formaldehyde[resole] resin; SP-1045) concentration and time of heat ageing on different relaxation transition characteristics and dynamic mechanical properties have been discussed. It has been observed that the molecular mobility is not affected, but only the sensitivity of E (in-phase modulus) in the dispersion region is affected by resin content and time of ageing. With increase in resin content in the vulcanizate, on ageing, the crosslinking reaction becomes more predominant over degradation of polymer chains and scission of crosslinks.

42—THE WEAR-RESISTANCE, AS DETERMINED BY THE ACCELEROTOR AND BOCKING FABRIC TESTER, AND TENSILE PROPERTIES OF RESIN-TREATED VISCOSE RAYON

Tests on lengths of spun viscose rayon fabric finished with urea–formaldehyde melamme–formaldehyde, methylated urea–formaldehyde, and ethylene urea–formaldehyde show that wear-resistance as measured by the Bocking Fabric Tester decreases directly with an increase in the resin content, whereas the rate of loss of weight during an Accelerotor test is also influenced by the type of resin. An increase in resin content led to an increase in initial modulus and secant modulus that was dependent on the type of resin, and to a decrease in extension and energy for rupture that was independent of the type of resin. It is suggested that these items are connected and that wear-resistance is influenced by the mechanical properties of the material. This is supported by the agreement between the initial modulus and Accelerotor results, and between the secant modulus at break, extension at break, and energy for rupture and the results obtanied on the Bocking Fabric Tester. Wear-resistance is increased by reducing the sti...

Studies on the Paper Yarn (Report 7)

We made experiments to find out the Resin Treatment method of thin paper. We tested how the properties of the same Resin affected a sheet of thin paper when it was finished over with Melamine Formaldehyde Resin.(1) Relationships between Resin added-% on fiber and the paper strength :Diy strength increased so far as the increase of Resin content of sheet was within 10%, but it decreases when the increase of Resin content was more than 17%.Wet strength had a tendency to increase in proportion to the Increase of Resin content so far as Resin content was low, but when Resin added-% become more than 10%, the increasing tendency of the wet strength was diminished, becoming 50-70% of the dry strength of untreated paper.(2) Aging conditions and the strength of treated paper :When Reisn directly prior to the gelling, was used, the paper strength was greater than in the case of (1). As for the aging conditions, the concentration of 15%-16% and the aging temperature of 80-90°C, are convenient for the manipulation in its industrial production.(3) Curing temperature. curing hour, and the strength : Though it is commonly believed that 130°C., 10mins. (the application of which conditions is common in the factories, ) are essential, but 100±5°C., 30 minutes. were perfect for the curing.