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The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.

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Conference Proceedings
EVA CURING STUDY BY DSC FOR SOLAR APPLICATION
Bruce F. Taylor, Timothy W. Womer, Robert Kadykowski, Robert A. Sickles, Jr., Luke A. Miller, May 2010
Ethylene vinyl acetate (EVA) has been used as encapsulant for solar cell application. the curing degree needs to be controlled to optimize the property. The traditional way to characterize the gel content (crosslinking degree) is by extraction using organic solvent. This method is time consuming and environmental unfriendly due to the toxic solvent. One new way to characterize gel content is by DSC. From the exothermic residue crosslink peak the gel content can be determined. The study indicates excellent correlation between these two methods. Compared with extraction method, DSC is easier and more cost efficient.
EFFECT OF HEAT AND SHEAR ON THE GELATINIZATION OF THERMOPLASTIC STARCH WITH VARIOUS PLASTICIZERS
Avinash Baji, Shing-Chung Wong, Todd A Blackledge, Siwei Leng, May 2010
Different compositions of starch/water/plasticizer slurries are prepared in a batch mixer followed by an equilibration time. The slurries were then subjected to different thermal and shear treatments. A rheological technique has been developed to track the influence of shear on the gelatinization process and the results are also supported by DSC and polarized light microscopy for static systems. Shear has a dramatic effect on gelatinization and the dependence of the onset and conclusion temperatures with slurry composition vary widely depending on the type of plasticizer used.
MECHANICAL PROPERTIES OF ELECTROSPUN COMPOSITES AND THEIR CRYSTALLINITY MEASUREMENTS USING X-RAY DIFFRACTION
Avinash Baji , Shing-Chung Wong , Todd A Blackledge , Siwei Leng, May 2010
Electrospinning method was used to produce nanoscale polymer fibers. The mechanical properties and toughness of the hydroxyapatite (HAP) reinforced poly(- caprolactone) (PCL) electrospun fibers were evaluated.The mechanical response of the electrospun composites was compared with that of the non-spun compression molded composites and it was determined that mechanical properties and the toughness values were enhanced when the materialƒ??s dimensions are reduced to the nanometer length scale. The crystallinity of the spun and the non-spun composites were determined using wide angle x-ray diffraction and the effect of crystallinity was assessed.
DIRECT ISOLATION OF BIFUNCTIONAL POLYPHENYLENE ETHER COPOLYMER
Miroslav Pastorek, Roman ?ermák, Jana Navrátilová, Martin Obadal, May 2010
A bi-functional polyphenylene ether copolymer is produced by oxidative coupling polymerization of 2,6 xylenol and TMBPA (Tetra Methyl Bisphenol A). The reaction takes place in a solvent, such as toluene, which needs to be removed in an ƒ??isolationƒ? processing step. The isolation can be done by precipitation of the copolymer with an anti-solvent such as isopropanol or by direct" isolation in a devolatilization extruder. This pape rde-scribes the devolatilization extrusion operation of low viscosity copolymer. Process conditions to control the desired residual solvent content in the product were investigated and the effect on the copolymer properties is reported."
EFFECTS OF HIGH INTENSITY SONICATION ON AN EPOXY RESIN: PRE- AND POST-CURE BEHAVIOR
Anita R. Rajan , Richard D. West , Vivak M. Malhotra, May 2010
The ultrasonic cavitation approach for the fabrication of polymer nanocomposites has proven effective for particle dispersion which improves the thermomechanical properties. However the effects of probe-style cavitation on the behavior of the polymer itself are not completely understood. While FTIR data show increased functional group intensity DSC measurements confirm no decrease in glass transition for EPON 862. It appears that sonication increases the storage modulus of epoxy especially at low temperatures though the maximum increase was observed for a sample which was sonicated for 5 minutes.
CONJUGATED POLYMER PHOTOVOLTAIC SOLAR CELLS MANUFACTURING AND INCREASING PERFORMANCE
Zhihua Guo, L. James Lee, David L. Tomasko, May 2010
Due to their lighter weight, conjugated (semiconducting) polymer cells have a potential of displacing conventional silicon cells. The most studied conjugated polymer solar cell is the bulk heterojunction cell. Here, the active layer is made up of a mixture of the conjugated polymer donor and the C60 based - fullerene acceptor. The efficiency of the cell is determined, using a solar simulator and the AM1.5G standards, after determining existence of an open circuit voltage (Voc) and short circuit current. Using Design of Experiments (DOE), Voc has been maximized. The variables considered in the DOE were solvent type, number of layers of PEDOT:PSS and polymer/fullerene mix, as well as spin-coating times and speeds, and annealing time, temperature and applications per cell layer. Other variables such as LiF insertion, electric or magnetic fields, nano-rods and nano-tubes will be studied in the future.
PHOTODEGRADATION OF ?-NUCLEATED POLYPROPYLENE
Jana Navrátilová , Leoš Vašek , Roman ?ermák, May 2010
The paper deals with the effects of nucleation on photodegradation of isotactic polypropylene. The starting polymer was modified by a specific ?- nucleating/clarifying agent Millad 3988 based on 1 3;2 4-bis(3 4-dimethylbenzylidene) sorbitol. Several concentrations were applied. Samples prepared by compression moulding were then exposed to UV-irradiation. Infrared spectroscopy showed that the degradation kinetics is similar for all the samples. Melting and crystallization behaviour of irradiated samples was followed using a differential scanning calorimetry. In all cases UV-irradiation led to decrease of melting/crystallization temperature as a result of polymer degradation. The surface cracking was observed using polarized light microscopy. The network of the surface cracking was significantly different for neat and nucleated samples. Introduction
PHOTODEGRADATION OF ?ñ-NUCLEATED POLYPROPYLENE
Jana Navrátilová , Leoš Vašek , Roman ?ermák, May 2010
The paper deals with the effects of nucleation on photodegradation of isotactic polypropylene. The starting polymer was modified by a specific ?ñ- nucleating/clarifying agent Millad 3988 based on 1,3;2,4-bis(3,4-dimethylbenzylidene) sorbitol. Several concentrations were applied. Samples prepared by compression moulding were then exposed to UV-irradiation. Infrared spectroscopy showed that the degradation kinetics is similar for all the samples. Melting and crystallization behaviour of irradiated samples was followed using a differential scanning calorimetry. In all cases UV-irradiation led to decrease of melting/crystallization temperature as a result of polymer degradation. The surface cracking was observed using polarized light microscopy. The network of the surface cracking was significantly different for neat and nucleated samples.
INCREASED ELECTRICAL CONDUCTIVITY FROM REDUCED CARBON NANOTUBE CONCENTRATIONS USING EXTENSIONAL FLOW MIXING
Alan Stall , Thomas Hicks , Carl Frauenpreis , Vladimir Sinani , Tatyana Samoylova, May 2010
Carbon nanotubes (CNTs) are extraordinarily expensive, and reduced concentration solutions are sought which retain critical physical properties, especially electrical conductivity. Currently, electrical conductivity requirements usually exceed conventional twin-screw mixing capabilities, forcing processors to use higher concentrations of CNTs, or revert to the use of chemicals, additives or wet polymerization. This research covers tests and provides data on a new extensional flow mixing method designed to increase particle distribution and dispersion by performing hundreds of repetitive extensional flow cycles over a 20 second residence time, thereby significantly achieving high conductivity while decreasing CNT concentration requirements by over 40%.
QUALITY CONTROL OF POLYMER PRODUCTS THROUGH SPECTRAL IMAGING AND CHEMOMETRICS METHODS
Ryan Gosselin , Denis Rodrigue , Carl Duchesne , Rubén González-Nuñez, May 2010
Spectral imaging is increasingly used to develop rapid and non-invasive analytical sensors in a variety of fields. This paper discusses the ability of chemometrics methods such as multivariate image analysis (MIA) and wavelet texture analysis (WTA) to extract meaningful information from spectral images enabling the user to monitor subtle spatio-temporal variations in thin polymer materials. Three case studies are proposed to illustrate the method: (1) detecting subtle crystallinity variations across pure polymer films (2) studying extrusion dynamics of wood/plastic composites making it possible to follow the mechanical properties on-line and (3) predicting the mechanical properties of polymer blend films using both spatial and spectral features. These case studies show that spectral imaging can effectively be used identify local property variability and help in overall process control.
QUALITY CONTROL OF POLYMER PRODUCTS THROUGH SPECTRAL IMAGING AND CHEMOMETRICS METHODS
Ryan Gosselin , Denis Rodrigue , Carl Duchesne , Rubén González-Nuñez, May 2010
Spectral imaging is increasingly used to develop rapid and non-invasive analytical sensors in a variety of fields. This paper discusses the ability of chemometrics methods, such as multivariate image analysis (MIA) and wavelet texture analysis (WTA), to extract meaningful information from spectral images, enabling the user to monitor subtle spatio-temporal variations in thin polymer materials. Three case studies are proposed to illustrate the method: (1) detecting subtle crystallinity variations across pure polymer films, (2) studying extrusion dynamics of wood/plastic composites making it possible to follow the mechanical properties on-line, and (3) predicting the mechanical properties of polymer blend films using both spatial and spectral features. These case studies show that spectral imaging can effectively be used identify local property variability and help in overall process control.
RESEARCH OF ENERGY-SAVING MECHANISM OF INTERNAL CIRCULATION FOUR-CYLINDER DIRECT-LOCKING TWO-PLATEN INJECTION MOLDING MACHINE
Alan Stall, Thomas Hicks, Carl Frauenpreis, Vladimir Sinani, Tatyana Samoylova, May 2010
Two savings (resource saving and energy saving) and four highs (high precision, high efficiency, high quiet, high performance price ratio) are the indicators to evaluate the performance of an injection molding machine. With the enhancement of environment consciousness, the energy consumption of an injection machine seems more important. Due to the internal circulation and servo drive system, the Internal Circulation Four-cylinder Direct-locking Two-platen Injection Molding Machine overcomes the disadvantages of the high energy consumption of the conventional full-hydraulic injection molding and reaches the highest standard of energy-saving injection molding machine. This paper firstly introduces the energy consumption composition and analyzes the energy-saving mechanism of the Internal Circulation Four-cylinder Direct-locking Two-platen Injection Molding Machine, and then verifies it by experimental means.
EXTENTIONAL FLOW MIXING PROVIDES MECHANICAL PROPERTIES IMPROVEMENTS FROM UNTREATED NANOCLAY COMPOSITES
Alan Stall , Thomas Hicks , Carl Frauenpreis , Vladimir Sinani , Tatyana Samoylova, May 2010
Nanoclay composites require inclusion of chemicals such as surface coatings and compatibilizers to achieve required physical performance. However these chemicals are costly not environmentally friendly and their use restricts the commercial applications. This research covers the use of a new extensional flow mixer which can make nanocomposites without chemical additives and give comparable results to conventional technology which does use these chemical additives. The significance is the elimination of the need for the expensive additives and creating a lower cost product that has food and environmental acceptance.
EXTENTIONAL FLOW MIXING PROVIDES MECHANICAL PROPERTIES IMPROVEMENTS FROM UNTREATED NANOCLAY COMPOSITES
Alan Stall , Thomas Hicks , Carl Frauenpreis , Vladimir Sinani , Tatyana Samoylova, May 2010
Nanoclay composites require inclusion of chemicals, such as surface coatings and compatibilizers to achieve required physical performance. However, these chemicals are costly, not environmentally friendly, and their use restricts the commercial applications. This research covers the use of a new extensional flow mixer which can make nanocomposites without chemical additives, and give comparable results to conventional technology which does use these chemical additives. The significance is the elimination of the need for the expensive additives, and creating a lower cost product that has food and environmental acceptance.
INITIAL STUDIES ON DOUBLE NETWORK GLASSES
Amara Aït Aissa, Myriam Cousineau-Pelletier, Ryan Gosselin, Carl Duchesne, Denis Rodrigue, May 2010
DGEBA-based epoxy and stoichiometric blends of flexible aliphatic and rigid aromatic amines are cured in two stages to produce double-network glasses. The low reactivity of the aromatic amine permits the selective reaction of the aliphatic amine in the first stage, and mechanical properties are measured above Tg without significantly advancing the cure. The second stage reacts remaining epoxide and aromatic amine functionalities. Network properties depend strongly on composition and conversion, however no phase separation is observed. Experimental results are compared with theoretical models of blend properties to illuminate the nature of the interactions between the two amines in the networks.
MIXING OF POLYMER POWDERS IN A ROTATING MOLD
Amara Aït Aissa , Myriam Cousineau-Pelletier , Ryan Gosselin , Carl Duchesne , Denis Rodrigue, May 2010
As rotational molding parts become more and more complex, understanding how the polymer moves inside a rotating mold is important for good parts quality. Since the polymer is in a powder form, a distribution in particle sizes is present and each size can have very different flow characteristics. In this work, powder mixing and flow behavior are studied in terms of homogeneity and time to achieve equilibrium. To do so, mixing experiments of free flowing polyethylene particles have been carried out in a rotating glass cylinder. The parameters studied are: rotational speed, filling ratio, relative powder composition and particles sizes. In order to follow particles of different sizes, the original powder was sieved and each sub-size group was differently colored to be tracked in motion. The experiments were filmed with a camera under different angles and image analysis is performed via the Grey Level Co-occurrence Matrix to quantify mixing dynamics and color intensity analysis (RGB) characterization to determine powder dispersion.
MORPHOLOGY AND MECHANICAL PROPERTIES IN WELD LINE OF INJECTION COMPRESSION MOLDINGS
Qian Qin, Gregory B. McKenna, May 2010
The weld line of injection moldings often becomes a problem since they are the weakest part of the molding and would affect aesthetic properties, especially when rigid fibers are incorporated into the resin. Cracks would usually initiate from weld lines especially when the resin is sensitive to notches. Therefore, the injection-compression molding technique was applied in an attempt to improve the surface appearance as well as strength of weld line regions. The effect of injection-compression molding conditions on the morphology and mechanical properties of the weld line region is discussed.
MECHANICAL HOLE BURNING SPECTROSCOPY TO PROBE POLYMER HETEROGENEITY
Qian Qin , Gregory B. McKenna, May 2010
Mechanical Hole Burning Spectroscopy (MSHB) was recently proposed as a method to probe the dynamic heterogeneity of polymeric materials. Here we show how the MSHB technique can be applied to a triblock copolymer and to polymer solutions. The heterogeneity of a styrene-isoprene-styrene block copolymer was investigated in the vicinity of its order-disorder transition temperature (ODT). It was found that MSHB is not only able to qualitatively distinguish the heterogeneous region from the homogenous one but also is sensitive to the ƒ??depthƒ? in the heterogeneous regime. We also examined the heterogeneity length scale represented by entanglement density by performing MSHB experiments on polystyrene solutions of various concentrations and molecular weights. We find that the MSHB response is not sensitive to the entanglement density while the behavior in the Rouse regime provides evidence of dynamic heterogeneity. The response appears homogeneous in the terminal regime.
EFFECTS OF DEFECT ON MECHANICAL PROPERTIES OF SHEET MOLDING COMPOUND
Vandita Pai-Paranjape, Jan-Pleun Lens, May 2010
Sheet molding compound (SMC) consisting glass fiber mat and unsaturated polyester resin has been used to make many structural parts with complicated shapes. However during the compression molding, defects such as weld line and undulation of sheets would generated. Therefore at current study, static tensile test and tensile fatigue test were performed by using SMC molded plates with weld line and notch to investigate the effect of defects. It was found that the tensile strength of SMC molded plates with weld line was almost same as that of plates with notch in the static and fatigue tests. That is to say that weld line damages the strength of plates similar to notch. And both of tensile fatigue strengths of SMC plates with or without the weld line were about 28% of static tensile strength.
LASER SURFACE TREATMENT OF THERMOPLASTIC POLYMERS: INFLUENCE OF THE ATMOSPHERE NATURE
Maxime Ricbourg , Jean-Pierre Habas , Pascal Pignolet, May 2010
This work demonstrates that the affinity of a polymer with a polar liquid can be modified with a pulsed Nd:Yag laser technique. Our results concern experiments carried out on a technical thermoplastic polymer. The amplitude and the persistence of the laser treatment are explored by contact angle measurements carried out on irradiated polymers. The influence of parameters such as the intensity of the laser beam is clearly shown. The nature and the pressure of the treatment gas (air oxygen argonƒ??) are of first importance since they directly control the positive or negative evolution of the polymer-liquid affinity.


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