Abstract: A polymer cement mortar (PCM) has been widely used as the material of repair and restoration work for concrete structure; however a PCM usually induces an environmental pollutant. Therefore, there is a need to develop PCM which is less impact to
environments. Usually, UM resin is known to be harmless to the environment. Accordingly, in this paper, the properties of the PCM using UM resin were studied. The general cement mortar and UM resin were mixed in the specified ratio. A certain percentage of PVA fibers, steel fibers and mixed fibers (PVA fiber and steel fiber) were added to enhance the flexural strength. The flexural tests were performed in order to investigate the flexural strength of each PCM. Experimental results showed that the strength of proposed PCM using UM resin is improved when they are compared with general cement mortar.
Abstract: Vacuum assisted resin transfer moulding (VARTM) is a promising manufacture process for making large and complex fiber reinforced composite structures. However, the complexity of the flow of the resin in the infusion stage usually leads to nonuniform property distribution of the produced composite part. In order to control the flow of the resin, the situation of flow should be mastered. For the safety of the usage of the produced composite in practice, the understanding of the property distribution is essential. In this paper, we did some trials on monitoring the resin infusion stage and evaluation for the fiber volume fraction distribution of the VARTM produced composite using the digital image correlation methods. The results showthat3D-DIC is valid on monitoring the resin infusion stage and it is possible to use 2D-DIC to estimate the distribution of the fiber volume fraction on a FRP plate.
Abstract: Interlaminar shear strength (ILSS) of fiber reinforced polymer composite is an important property for most of the structural applications. Matrix modification is an effective method used to improve the interlaminar shear strength of composite. In this paper, EPON 862/w epoxy system was modified using Tetraethyl orthosilicate (TEOS) electrospun nanofibers (ENFs) which were produced using electrospinning method. Unmodified and nanofibers modified resins were used to fabricate glass fiber reinforced polymer composite (GFRP) using H-VARTM method. The ILSS of the Glass Fiber Reinforced Polymeric Composites (GFRP) was investigated. The study shows that introduction of TEOS ENFs in the epoxy resin enhanced the ILSS of GFRPby 15% with 0.6% wt. fraction of TEOS ENFs.
Abstract: Shellac is a natural polyester resin secreted by insects. Pectins are natural, non-toxic and water-soluble polysaccharides extracted from the peels of citrus fruits or the leftovers of apples. Both polymers are allowed for the use in the pharmaceutical industry and as a food additive. SSB Aquagold® is the aqueous solution of shellac and can be used for a coating process as an enteric or controlled drug release polymer. In this study, tablets containing 10 mg methylene blue as a model drug were prepared with a rotary press. Those tablets were coated with mixtures of shellac and one of the pectin different types (i.e. CU 201, CU 501, CU 701 and CU 020) mostly in a 2:1 ratio or with pure shellac in a small scale fluidized bed apparatus. A stable, simple and reproducible three-stage coating process was successfully developed. The drug contents of the coated tablets were determined using UV-VIS spectrophotometer. The characterization of the surface and the film thickness were performed with the scanning electron microscopy (SEM) and the light microscopy. Release studies were performed in a dissolution apparatus with a basket. Most of the formulations were enteric coated. The dissolution profiles showed a delayed or sustained release with a lagtime of at least 4 h. Dissolution profiles of coated tablets with pure shellac had a very long lagtime ranging from 13 to 17.9 h and the slopes were quite high. The duration of the lagtime and the slope of the dissolution profiles could be adjusted by adding the proper type of pectin to the shellac formulation and by variation of the coating amount. In order to apply a coating formulation as a colon delivery system, the prepared film should be resistant against gastric fluid for at least 2 h and against intestinal fluid for 4-6 h. The required delay time was gained with most of the shellac-pectin polymer mixtures. The release profiles were fitted with the modified model of the Korsmeyer-Peppas equation and the Hixson-Crowell model. A correlation coefficient (R²)> 0.99 was obtained by Korsmeyer-Peppas equation.
Abstract: Polybag and mulch film in agricultural field are used plastics which caused environmental problems after transplantation and planting processes due to the discarded wastes. Thus a degradable polybag was designed in this study to replace non degradable polybag with natural biodegradable resin that is widely available, namely sago starch (SS) and polyvinyl alcohol (PVA). Hybrid blend consists of SS, PVA and linear low density polyethylene (LLDPE) was compounded at different ratios. The thermal and mechanical properties of the blends were investigated. Hybrid films underwent landfill degradation tests for up to 2 months. The films showed gelation and melting transition existed for all three systems with significant melting peaks by LLDPE and PVA. All hybrid blends loses its LLDPE semi crystalline characteristics as PVA and SS systems had disrupted crystallinity and enhanced the amorphosity of the hybrid system. Generally, blending SS with PVA improves the mechanical properties of the SS based materials. Tensile strength of each film was also decreased with the increase of SS contents while its modulus had increased with SS content.
Abstract: Influences of the amount of phenolic, curing temperature and curing time on the Mechanical Properties of phenolic/fiber composite were investigated by using two-level factorial design. The latter was used to determine the affects of those factors on mechanical properties. The purpose of this study was to investigate the affects of amount of phenolic, curing temperature and curing time of the composite to determine the best condition for mechanical properties according to MIL-I-24768 by the tensile strength is more than 103 MPa.
Abstract: Natural fibers are considered to have potential use as reinforcing agents in polymer composite materials because of their principal benefits: moderate strength and stiffness, low cost, and being an environmental friendly, degradable, and renewable material. A study has been carried out to evaluate impact properties of composites made by areca fibers reinforced urea formaldehyde, melamine urea formaldehyde and epoxy resins. The extracted areca fibers from the areca husk were alkali treated with potassium hydroxide (KOH) to obtain better interfacial bonding between fiber and matrix. Then composites were produced by means of compression molding technique with varying process parameters, such as fiber condition (untreated and alkali treated), and fiber loading percentages (50% and 60% by weight). The developed areca fiber reinforced composites were then characterized by impact test. The results show that, impact strength increase with increase in the loading percentage. It is observed that, treated areca fiber reinforcement increases impact strength when compared to untreated areca fiber reinforcement.
Abstract: Severe damages may occur during the drilling of carbon fiber reinforced plastics (CFRP). In practice, this damage is limited by adding a backup support to the drilled parts. For some aeronautical parts with curvatures, backing up parts is a demanding process. In order to simplify the operation, this research studies the effect of using a configurable setup to support parts on the resulting quality of drilled holes. The test coupons referenced in this study are twenty four-plies unidirectional laminates made of carbon fibers and epoxy resin. Different signals were measured during the drilling process for these laminates, including the thrust force, the displacement and the acceleration. The processing of these signals demonstrated that the damage is due to the combination of two main factors: the spring-back of the thin part and the thrust force. The results found were confirmed for different feeds and speeds. When the distance between supports is increased, it is observed that the spring-back increases but the thrust force decreases. The study proves the feasibility of unsupported drilling of thin CFRP laminates without creating any observable damage.
Abstract: Water borne polyurethane (PU) based on newly prepared hyperbranched poly (amine-ester) (HBPAE) was applied and evaluated as organic coating material. HBPAE was prepared through one-pot synthesis between trimethylol propane as a core and AB2 branched monomer which was obtained via Michal addition of methyl methacrylate (MMA) and diethanol amine (DEA). PU was prepared from HBPAE using different ratios of toluene diisocyanate (TDI) to form cured coating film. The prepared HBPAE was characterized using; GPC, FT-IR and 1H-NMR. The mechanical properties (impact, hardness, adhesion, and flexibility), thermal properties (DSC and TGA) and chemical resistance of the applied film were estimated. The results indicated 50% of TDI is the selected ratio. This formulation represents a promising candidate to be used as coating material.
Abstract: In the course of the present work, plain (nonencapsulated)
and microencapsulated polyphenols were produced
using olive mill wastewater (OMW) as raw material, in order to be
used for enrichment of yogurt and dairy products. The OMW was
first clarified by using membrane technology and subsequently the
contained poly-phenols were isolated by adsorption-desorption
technique using selective macro-porous resins and finally recovered
in dry form after been processed by RO membrane technique
followed by freeze drying. Moreover, the polyphenols were
encapsulated in modified starch by freeze drying in order to mask the
color and bitterness effect and improve their functionality. The two
products were used successfully as additives in yogurt preparations
and the produced products were acceptable by the consumers and
presented with certain advantage to the plain yogurt. For the herein
proposed production scheme a patent application was already
submitted.
Abstract: In this paper, taking Chinese Nanjing Metro ALSTOM vehicle synthesis brake as an example, the subway with synthetic brake shoe formula components of final product performance, has done a lot of research and performance test, final is drawn with hybrid fiber as reinforcing material, modified phenolic resin as matrix material, and then filling friction modifier performance, by the hot pressing process made a new type of domestic subway brake shoe. The product of the test performance indicators that can replace the similar foreign products.
Abstract: The pigments covered by film-forming polymers have
opened a prospect to improve the quality of water-based printing
inks. In this study such pigments were prepared by the initiated
polymerization of styrene and methacrylate derivative monomers in
the aqueous pigment dispersions. The formation of polymer films
covering pigment cores depends on the polymerization time and the
ratio of pigment to monomers. At the time of 4 hours and the ratio of
1/10 almost pigment particles are coated by the polymer. The formed
polymer covers of pigments have the average thickness of 5.95 nm.
The size increasing percentage of the coated particles after a week is
4.5 %, about fourteen-fold lower than of the original ones. The
obtained results indicate that the coated pigments are improved
dispersion stability in water medium along with a guarantee for the
optical colour.
Abstract: Viscous heating becomes significant in the high speed
resin coating process of glass fibers for optical fiber manufacturing.
This study focuses on the coating resin flows inside the capillary
coating die of optical fiber coating applicator and they are numerically
simulated to examine the effects of viscous heating and subsequent
temperature increase in coating resin. Resin flows are driven by fast
moving glass fiber and the pressurization at the coating die inlet, while
the temperature dependent viscosity of liquid coating resin plays an
important role in the resin flow. It is found that the severe viscous
heating near the coating die wall profoundly alters the radial velocity
profiles and that the increase of final coating thickness by die
pressurization is amplified if viscous heating is present.
Abstract: This study was aimed to study the probability about
the production of fiberboard made of durian rind through latex with
phenolic resin as binding agent. The durian rind underwent the
boiling process with NaOH [7], [8] and then the fiber from durian
rind was formed into fiberboard through heat press. This means that
durian rind could be used as replacement for plywood in plywood
industry by using durian fiber as composite material with adhesive
substance. This research would study the probability about the
production of fiberboard made of durian rind through latex with
phenolic resin as binding agent. At first, durian rind was split,
exposed to light, boiled and steamed in order to gain durian fiber.
Then, fiberboard was tested with the density of 600 Kg/m3 and 800
Kg/m3. in order to find a suitable ratio of durian fiber and latex.
Afterwards, mechanical properties were tested according to the
standards of ASTM and JIS A5905-1994. After the suitable ratio was
known, the test results would be compared with medium density
fiberboard (MDF) and other related research studies. According to
the results, fiberboard made of durian rind through latex with
phenolic resin at the density of 800 Kg/m3 at ratio of 1:1, the
moisture was measured to be 5.05% with specific gravity (ASTM D
2395-07a) of 0.81, density (JIS A 5905-1994) of 0.88 g/m3, tensile
strength, hardness (ASTM D2240), flexibility or elongation at break
yielded similar values as the ones by medium density fiberboard
(MDF).
Abstract: Carbon fibers have specific characteristics in
comparison with industrial and structural materials used in different
applications. Special properties of carbon fibers make them attractive
for reinforcing and fabrication of composites. These fibers have been
utilized for composites of metals, ceramics and plastics. However,
it-s mainly used in different forms to reinforce lightweight polymer
materials such as epoxy resin, polyesters or polyamides. The
composites of carbon fiber are stronger than steel, stiffer than
titanium, and lighter than aluminum and nowadays they are used in a
variety of applications. This study explains applications of carbon
fibers in different fields such as space, aviation, transportation,
medical, construction, energy, sporting goods, electronics, and the
other commercial/industrial applications. The last findings of
composites with polymer, metal and ceramic matrices containing
carbon fibers and their applications in the world investigated.
Researches show that carbon fibers-reinforced composites due to
unique properties (including high specific strength and specific
modulus, low thermal expansion coefficient, high fatigue strength,
and high thermal stability) can be replaced with common industrial
and structural materials.
Abstract: It is well known that enhancing interfacial adhesion
between inorganic filler and matrix resin in a composite lead to
favorable properties such as excellent mechanical properties, high
thermal resistance, prominent electric insulation, low expansion
coefficient, and so on. But it should be avoided that much excess of
coupling agent is reacted due to a negative impact of their final
composite-s properties. There is no report to achieve classification of
the bonding state excepting investigation of coating layer thickness.
Therefore, the analysis of the bonding state of the coupling agent
reacted with the filler surface such as BN particles with less functional
group and silica particles having much functional group was
performed by thermal gravimetric analysis and pyrolysis GC/MS. The
reacted number of functional groups on the silane-coupling agent was
classified as a result of the analysis. Thus, we succeeded in classifying
the reacted number of the functional groups as a result of this study.
Abstract: In this work we investigated the behavior of methane
hydrates dispersed in crude oils from different fields at temperatures
below 0°C. In case of crude oil emulsion the size of water droplets is
in the range of 50e100"m. The size of hydrate particles formed from
droplets is the same. The self-preservation is not expected in this
field. However, the self-preservation of hydrates with the size of
particles 24±18"m (electron microscopy data) in suspensions is
observed. Similar results were obtained for four different kinds of
crude oil and model system such as asphaltenes, resins and wax in ndecane.
This result can allow developing effective methods to prevent
the formation and elimination of gas-hydrate plugs in pipelines under
low temperature conditions (e. g. in Eastern Siberia). There is a
prospective to use experiment results for working out the technology
of associated petroleum gas recovery.
Abstract: Materials added to the matrix help improving operating properties of a composite. This experimental study has targeted to investigate this aim where Silicon Oxide particles were added to glass fibre and epoxy resin at an amount of 15% to the main material to obtain a sort of new composite material. Erosive wear behavior of epoxy-resin dipped composite materials reinforced with glass fibre and Silicon Oxide under three different impingement angles (30°, 60° and 90°), three different impact velocities (23, 34 and 53 m/s), two different angular Aluminum abrasive particle sizes (approximately 200 and 400 μm) and the fibre orientation of 45° (45/-45) were investigated. In the test results, erosion rates were obtained as functions of impingement angles, impact velocities, particle sizes and fibre orientation. Moreover, materials with addition of Silicon Oxide filler material exhibited lower wear as compared to neat materials with no added filler material. In addition, SEM views showing worn out surfaces of the test specimens were scrutinized.
Abstract: The rate of nitrate adsorption by a nitrate selective ion
exchange resin was investigated in a well-stirred batch experiments.
The kinetic experimental data were simulated with diffusion models including external mass transfer, particle diffusion and chemical
adsorption. Particle pore volume diffusion and particle surface diffusion were taken into consideration separately and simultaneously
in the modeling. The model equations were solved numerically using the Crank-Nicholson scheme. An optimization technique was
employed to optimize the model parameters. All nitrate concentration
decay data were well described with the all diffusion models. The
results indicated that the kinetic process is initially controlled by external mass transfer and then by particle diffusion. The external
mass transfer coefficient and the coefficients of pore volume diffusion and surface diffusion in all experiments were close to each
other with the average value of 8.3×10-3 cm/S for external mass
transfer coefficient. In addition, the models are more sensitive to the
mass transfer coefficient in comparison with particle diffusion. Moreover, it seems that surface diffusion is the dominant particle
diffusion in comparison with pore volume diffusion.
Abstract: Gaharu that produced by Aquilaria spp. is classified as
one of the most valuable forest products traded internationally as it is
very resinous, fragrant and highly valuable heartwood. Gaharu has
been widely used in aromatheraphy, medicine, perfume and religious
practices. This work aimed to determine the factors affecting solid
liquid extraction of gaharu oil using hexane as solvent under
experimental condition. The kinetics of extraction was assumed and
verified based on a second-order mechanism. The effect of three
main factors, which were temperature, reaction time and solvent to
solid ratio were investigated to achieve maximum oil yield. The
optimum condition were found at temperature 65°C, 9 hours reaction
time and solvent to solid ratio of 12:1 with 14.5% oil yield. The
kinetics experimental data agrees and well fitted with the second
order extraction model. The initial extraction rate (h) was 0.0115
gmL-1min-1; the extraction capacity (Cs) was 1.282gmL-1; the second
order extraction constant (k) was 0.007 mLg-1min-1 and coefficient of
determination, R2 was 0.945.