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Conference Proceedings
DESIGN CONCEPTS OF LINK CROSS-SECTIONS FOR DEVELOPING COMPOSITE-BASED LONG-REACH ROBOTIC ARMS
Metallic robotic arms currently dominate in industry but due to their intrinsic weight have limited usefulness for large-scale applications in terms of precision and speed.This research work investigates the feasibility of using solid or cellular polymeric composite materials or a combination thereof for the construction of long-reach robotic arms.This paper summarizes the preliminary study of the crosssectional geometry of the links in terms of stiffness-andstrength- to-weight ratios that would be capable of preserving high precision under time-dependent external excitations.
MORPHOLOGY OF SULFONATED STYRENIC PENTABLOCK COPOLYMER
SOLUTIONS AND MEMBRANES
In this paper, we report a systematic investigation of the morphology of sulfonated styrenic pentablock copolymer solutions and membranes obtained from Kraton Polymers LLC. Small angle x-ray scattering (SAXS) revealed that all the solutions exhibited isotropic micellar morphology. The solution SAXS data was modeled using the Kinning-Thomas model to obtain radius of micelle core, aggregation number, radius of closest approach between two micelles, volume fraction of micelles, and volume fraction of solvent in micelle corona. In contrast, the membranes exhibited anisotropic morphology with different d-spacings in-plane and through-plane.
POLYMER SOLAR CELL
The Sun is providing the Earth with an enormous
amount of energy, approximately 200ƒ??000 times the capacity
of the total energy production facilities. Only a very small
amount of this energy is used. Hence the thought of
developing a device that effectively and cheaply harvests the
solar energy is very attractive. There is a line of problems
connected with using the solar energy. Firstly the averaged
yearly local intensity is varying from less than 100Wmƒ??2 to a
little more than 300Wmƒ??2. This means that sunlight must be
collected over a very large area in order to produce an
amount of electrical energy comparable with that consumed
by a city, fabric or even a house. Secondly the energy of the
sunlight cannot be directly used in any way. Therefore,
turning the radiative solar energy into a more useable energy
type is the primary objective. There exists two different
approaches to this problem but with either approach a rather
large amount of the radiative energy is lost in the conversion.
ƒ?› Conversion into thermal energy.
ƒ?› Conversion into electrical energy.
The solar light is converted into thermal energy when
interacting with matter. This can be used for heating water
and house warming etc. The applications are naturally limited
as a very large part of our energy consumption is electrical
energy. The silicon solar cell (SSC) has been and is the most
used way to convert solar energy into electrical energy. A
short summary of the history and basic physical principles of
the silicon solar cells is presented in the following sections
A STUDY OF USING INTERNET TECHNOLOGY TO IMPROVE LEARNING EFFICIENCY OF LEARNING INJECTION MOLDING TECHNOLOGY
Now internet is a very important source that we get the new knowledge, and e-learning is a popular type of learning new technology or existed knowledge. This study developed an e-learning system of injection molding by the standard of SCORM 2004. A learner can attend class by a computer with a network without the limitation of time or places. We let 32 persons of using the system to learn for test-retest experiment. And using paired samples t-test to analyze the results of the experiment can get that t-value is -14.182 and p value is smaller than 0.05.
MECHANICAL PROPERTIES OF INJECTION MOLDED THERMOPLASTIC POLYOLEFIN (TPO) CELLULAR FOAMS
In this study mechanical properties of injection molded Thermoplastic Polyolefin (TPO) foams were investigated. Closed cell TPO foams were prepared using injection molding process. Tensile properties impact resistance of various injection molded TPO samples were correlated with different foam morphologies. The findings show that the mechanical properties were significantly affected by the foam morphologies. The experimental results obtained from this study can be used to predict the microstructure and mechanical properties of cellular injection molded TPO foams prepared with different processing parameters
SOFT AND FLEXIBLE IONOMER WITH GOOD SCRATCH RESISTANCE
New ionomers have been developed to afford exceptional soft feel, high flexibility, and good scratch resistance. The thermoplastic characteristics enable ease of melt processing, good adhesion to various substrates, HF weldability, and deep draw thermal forming. The new ionomer is optically clear and glossy, and can be colored and printed. It has good compatibility with various pigments and additives for enhanced esthetic effects and outdoor weatherability. The soft feel and scratch resistance, coupled with the versatile processibility, make the new ionomers well-suited for protective and decorative applications. It contains no intentionally added halogen and can be recycled or incinerated to serve as an environmentally friendly alternative to flexible PVC or a lower cost alternative to flexible TPU.
ANALYSIS OF RESULTS VARIATIONS AT HIGH DEFORMATIONS IN TENSILE TESTS OF PE FILMS
Plastic films properties are very sensitive to
evaluation conditions and other factors that are present
during tensile testing procedures. A study of standard
tensile test results variation was performed on extruded
HDPE films in order to determine which factors have
greater influence on repeatability and how to reduce their
influences. Finite element simulations were used as a tool
understand the sources of variations. Three HDPE resins
from different manufactures with similar properties were
selected as samples and two testing machine operators
were considered in the analysis. Other variables such as
film blowing conditions and sample geometry were also
considered in the study.
ANALYSIS OF RESULTS VARIATION AT HIGH DEFORMATIONS IN TENSILE TESTS OF PE FILMS
Plastic films properties are very sensitive to evaluation conditions and other factors that are present during tensile testing procedures. A study of standard tensile test results variation was performed on extruded HDPE films in order to determine which factors have greater influence on repeatability and how to reduce their influences. Finite element simulations were used as a tool understand the sources of variations. Three HDPE resins from different manufactures with similar properties were selected as samples and two testing machine operators were considered in the analysis. Other variables such as film blowing conditions and sample geometry were also considered in the study.
A STUDY ON ELECTRICALLY CONDUCTIVE BLENDS OF POLYCARBONATE/ LIQUID CRYSTALLINE POLYMER/MULTI-WALLED CARBON NANOTUBES
A thermotropic liquid crystalline polymer (LCP) was introduced into the composites of polycarbonate (PC) and multi-walled carbon nanotube (CNT) with the goal of improving electrical conductivity and mechanical properties. It was hypothesized that double percolation networks would be produced first from aligned, continuous fibrils of LCP and then by CNT networks within LCP fibrils. Two grades of LCP were chosen: Vectra A950 (VA950), and Vectra V400P (V400P) from Hoechst Celanese. The CNT used was Baytubes, C-150P and the PC used was Lexan 121. The compounds were prepared by melt-blending in a twin-screw mini-compounder and injection molded using a mini-injection molder. The LCP content was kept at 20 wt% and the CNT contents were varied from 0.5 to 15 wt%. Only PC/VA950 blend showed fibrils of LCP. However, these fibrils turned into droplets with the addition of CNT. Results from TEM showed that CNT preferentially located inside the LCP domains as predicted from the value of spreading coefficient. The electrical conductivity showed the following order (the numbers in parenthesis are electrical percolation threshold): PC/CNT (2%) > PC/VA950P/CNT (3%) > PC/V400P/CNT (4%). The resulting discontinuity of the LCP droplet phase with CNTs located inside disrupted the electrically conductive pathways and resulted in lower electrical conductivity values. The value of storage modulus showed improvement by the addition of CNT and VA950.
PREPARATION AND CHARACTERIZATION OF POLY(ETHYLENE TEREPHTHALATE)/CARBON NANOTUBE COMPOSITES WITH SURFACE MODIFIED CARBON NANOTUBES
Surface of the multi walled carbon nanotubes was modified by purification with strong acid mixture followed by treatment with poly(ethylene glycol) (PEG). Poly(ethylene terephthalate) (PET) based conductive polymer composites were prepared with untreated and modified carbon nanotubes by using a twin screw extruder. Carbon nanotube characterization methods showed the formation of new functional groups on carbon nanotube surface after purification and chemical treatment. Surface modification of the carbon nanotubes increased the tensile strength of the composites.
WEATHERING OF TRANSPARENT POLYESTER-CARBONATES UNDER HIGH INTENSITY DISCHARGE LIGHTING
Weathering of transparent materials based on polycarbonate homopolymer and a new improved weatherability resorcinol arylate copolymer have been investigated under the exposure of various high intensity discharge (HID) light sources. The effect of lighting fixture design variables such as bulb type wattage and bulb to lens distance onto the material performance as a lens or refractor has been correlated with the amount of UV and the temperature at which the material is exposed.A model that can predict the material photoyellowing based on the exposure conditions has been developed.
EFFECT OF CITRATE PLASTICIZER ON THE THERMAL AND RHEOLOGICAL PROPERTIES OF POLYLACTIC ACID
This research work is focused on the effect of citrate plasticizers on thermal and viscoelastic properties of Polylactic acid (PLA). As expected the glass transition temperature decreases with addition of citrates demonstrating the effectiveness of citrates as a PLA plasticizer. It was observed that the decrease in glass transition temperature with the increase of citrate content behaves in exponential way. Viscoelasticity of PLA is considerably affected by the presence of citrate plasticizer. The zero shear-rate viscosity and pseudoplasticity index decrease could be correlated with the plasticizer content by using an exponential function.
CONVENTIONAL PROCESSING AND RHEOLOGY OF NANOCOMPOSITES ABS/MONTMORILLONITE
ABS/montmorillonite nanocomposites were obtained via conventional melt mixing by single screw capillary extrusion. Nanocomposites from 0.5 to 9 % Volumetric Fraction (VF) of nanoclay were formulated. Melt rheology shows a decrease in the Newtonian range as modified clay increases. The opposite is true for the viscosity at zero shear. Shear thinning behavior is observed as clay content is increased. From XRD, it is inferred an increase of nanoclay d-spacing independent from the clay content in samples from the capillary rheometer. TEM shows both intercalated and exfoliated clay structures obtained from capillary extrusion. The processing conditions in conventional equipment for plastics transformation, i.e. extrusion, may lead to obtain intercalated and exfoliated nanocomposites, without the need for complex tooling configuration.
EFFECTS OF SOLVENT-CASTING CONDITIONS ON THE MORPHOLOGY AND PROPERTIES OF HIGHLY FLUORINATED POLY (ARYLENE ETHERSULFONE) COPOLYMER FILMS FOR POLYMER ELECTROLYTE MEMBRANES
Poly(arylene ether sulfone) block copolymers are studied as candidates for membrane materials in polymer electrolyte membrane fuel cells. Highly fluorinated versions are of particular interest as increase hydrophobicity of the fluorinated blocks will induce greater phase separation resulting in improved proton conductivity. This work studies the effect of processing temperature on membrane properties and compares results for highly-fluorinated poly(arylene ether sulfones) to results for the sparingly fluorinated copolymer. Proton conductivities are below the expected values, which is likely due to high processing temperatures having detrimental effects on ion clusters in copolymer chain coupled with a lack of ample time for phase separation. Studies of the phase separation kinetics and final film morphologies can help better understand the drying process.
TIME DEPENDENT PIEZORESISTIVE BEHAVIOR OF POLYVINYLIDENE
FLUORIDE / CARBON NANOTUBE CONDUCTIVE
In this work conductive nano composite has been
prepared by incorporating multiwall carbon nanotubes
(MWCNT) in polyvinylidene fluoride (PVDF) by melt
blending method. The creep behavior of PVDF
composite is studied by compression test. To study the
time and stress dependent piezoresistive behavior of the
prepared composite mechanical testing was
synchronized with electrical resistance measurement.
Comparison of mechanical creep with the creepdependent
resistance implied that there is a conducting
percolation attributed to the physical contacts between
MWCNT and a mechanical network formed by the
molecular chains of the polymer matrix and the
interaction between the filler and the matrix.
TIME DEPENDENT PIEZORESISTIVE BEHAVIOR OF POLYVINYLIDENE FLUORIDE / CARBON NANOTUBE CONDUCTIVE
In this work conductive nano composite has been prepared by incorporating multiwall carbon nanotubes (MWCNT) in polyvinylidene fluoride (PVDF) by melt blending method. The creep behavior of PVDF composite is studied by compression test. To study the time and stress dependent piezoresistive behavior of the prepared composite, mechanical testing was synchronized with electrical resistance measurement. Comparison of mechanical creep with the creepdependent resistance implied that there is a conducting percolation attributed to the physical contacts between MWCNT and a mechanical network formed by the molecular chains of the polymer matrix and the interaction between the filler and the matrix.
INVESTIGATION OF POLYCAPROLACTONE/STARCH BASED MATERIAL MELT
PROCESSED BLENDS
Research on biodegradable materials has been
stimulated due to environmental and economic concerns.
The blends of polycaprolactone and a starch based
material were prepared by compounding with a twin-screw
Brabender. DSC TGA and DMTA were used to
characterize the blends and indicated some degree of
interaction between the neat polymers. With respect to the
neat PCL DSC results of the blends revealed peak shift
and depression in either the melting or melt crystallization
point and the glass transition temperatures obtained from
the maxima loss tangent peaks of DMTA were also shifted.
TGA studies showed decreased thermal stability of the
PCL rich phase blends with increasing wt.% starch based
material. Tensile test concluded improved modulus in the
blends in comparison with the neat PCL. (Ref.9)
FULLY BIODEGRADABLE BAMBOO FIBER AND POLYLACTIDE COMPOSITES
Bamboo fiber may withhold great potential as an alternative to wood, and bamboo can be a raw material to fabricate a composite material and its applicability is being widely investigated. Cellulose fibers can be aligned to the length of the bamboo providing maximum tensile and flexural strengths and rigidity. Increased research in the recent years has considerably contributed to the use of bamboo fibers as a reinforcing material for broader applications. However, it is difficult to obtain polymer/bamboo fiber composite having its excellent mechanical properties, because the bamboo fibers covered with lignin show lack of interfacial adhesion. Therefore, it is necessary to enhance the interfacial adhesion by extracting lignin without microstructure disruption and adding silane coupling agents.
In this research the influence of silane coupling agent, composites with pristine bamboo fiber, delignified bamboo fiber, and delignified and silane treated bamboo fiber were newly prepared and investigated, respectively.
MULTI-COMPONENT TECHNIQUE: HYBRID PRIMARY FORMING OF PLASTICS PARTS WITH ELECTRICALLY CONDUCTIVE TRACKS
Nowadays various technologies are capable of producing hybrid plastics/metal-composites. However they all have disadvantages due to several manufacturing steps and limitations in the achievable complexity of the part geometry. An innovative approach to produce plastics/metal-composites is to combine the injection molding of plastics and the die casting of metals to a new hybrid multi-component process within a single mould and on a single machine. Combining the plastics injection molding and the die casting of low-melting metal alloys plastics parts with integrated electrically conductive tracks can be produced. A selection of promising results concerning this new process is presented.
MULTI-COMPONENT TECHNIQUE: HYBRID PRIMARY FORMING OF PLASTICS PARTS WITH ELECTRICALLY CONDUCTIVE TRACKS
Nowadays, various technologies are capable of producing hybrid plastics/metal-composites. However, they all have disadvantages due to several manufacturing steps and limitations in the achievable complexity of the part geometry. An innovative approach to produce plastics/metal-composites is to combine the injection molding of plastics and the die casting of metals to a new hybrid multi-component process within a single mould and on a single machine. Combining the plastics injection molding and the die casting of low-melting metal alloys, plastics parts with integrated electrically conductive tracks can be produced. A selection of promising results concerning this new process is presented.
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