SPE Library
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
EXFOLIATION AIDS FOR PREPARATION OF POLYMER-LAYERED SILICATE NANOCOMPOSITES
Jinling Liu, William Rodgers, Ting Cao, Michael Thompson, May 2011
The use of supercritical CO2 and two cosolvents were examined to aid exfoliation of an organoclay within a thermoplastic polyolefin. The study examined the manner in which the gas environment was used in the presence of the clay, compatibilizer and matrix. This was done with an extensional flow mixer. The results of the work showed that supercritical CO2 was most effectively utilized when in the presence of the organoclay and compatibilizer as it melted. Both water and ethanol were effective cosolvents, producing smaller tactoids with a narrower size distribution. Ethanol was found to be the most effective as a cosolvent.
HOT MELT MIXING OF INDOMETHACIN AND SOLUPLUS FOR ORAL DELIVERY
Graciela Terife, Costas Gogo, Peng Wang, May 2011
An amorphous solid suspension for oral drug delivery was prepared via Hot Melt mixing 30wt% of Indomethacin (INM) with Soluplus. The melt mixed sample was characterized through optical microscopy, DSC, FR-IR and XRD. Dissolution test showed that INM release was pH-dependent; in the case of the amorphous solid suspension within 1h 90% of INM was released at pH7.4, while only 0.02% at pH1.2, probably a consequence of hydrogen bonds formed between INM and the polymer. The fastest release was obtained from the foamed amorphous solid suspension, followed by un-foamed amorphous solid suspension, then pure INM and finally the physical mixture.
EFFECT OF THE ADDITION OF CARBON NANOTUBES WITH POLYSTYRENE GRAFTING ON THE GLASS TRANSITION BEHAVIOR OF POLYSTYRENE
Brian Grady, Abhijit Paul, Warren Ford, May 2011
The effect of single-walled carbon nanotubes on the glass transition of polystyrene with and without polystyrene grafting has been quantified. Three different molecular weights, 2,800, 15,000 and 50,000 g/mol, of polystyrene were grafted to the nanotubes with the weight fractions of grafted chains approximately the same. Composites with 50 K grafted nanotubes were statistically identical in terms of the glass transition temperature and change in heat capacity. Composites with lower molecular weight grafted nanotubes did show significant differences vs. the composites with ungrafted nanotubes, especially in terms of the change in heat capacity.
EFFECT OF MOLECULAR WEIGHT DISTRIBUTION ON THE WELD-LINE INTERFACE IN INJECTION MOLDED POLYPROPYLENE
Katsuyuki Yokomizo, May 2011
On the basis of a coarse-grained molecular dynamics with bead-spring polymer chain model, we investigated an interdiffusion of macromolecules of the separated flow fronts and stress-strain behavior under simple extensional deformation of the interfacial region. In polydisperse system, it is predicted that depletion of long chains takes place at the interface where short chains preferentially locate. Significant improvement of interfacial strength is predicted when molecular weight distribution is narrow enough to have a considerable overlap between long chains belonging to each phase separated by the interface. The calculation result reproduced the experiment on the interfacial strength of polyolefin material.
PROPERTIES OF POLY (PROPYLENE CARBONATE) PRODUCED VIA SK ENERGY'S GREENPOL TECHNOLOGY
Myung-Ahn Ok, Minho Jeon, May 2011
Polypropylene carbonate (PPC) is an amorphous polymer made by alternating copolymerization of carbon dioxide and propylene oxide. SK Energy developed its own proprietary technology with a highly active catalyst for this polymerization and has begun to produce PPC in its continuous process type pilot plant since late 2008 with a trade name GreenPolTM. In this paper, we are describing the typical properties of PPC such as general physical properties, barrier properties, thermal and UV stability, and smoke density along with some rheological properties.
A GREEN PROCESS FOR THE SYNTHESIS OF MESOPOROUS SILICA MATERIALS
Honghu Dai, Daoxing Dai, Jintao Yang, Yunguo Zhou, Zhengdong Fei, Feng Chen, Mingqiang Zhong, May 2011
In this paper, mesoporous silica and functionalized silicas were prepared by a green template, polyamidoamine (PAMAM) dendrimers. Three silane coupling agents, 3-triethoxysilylpropyl- amine (APTES), -methylacryloyl oxypropyl trimethoxysilane (MAPTMS) and N-[3-(trimethoxysilyl)propyl]ethylenediamine (AEAPTMS) were used for modification on pore surface. The characters of synthesized silicas were investigated in detail. The results showed that controllable pore diameters, narrow pore size distributions, high surface area and pore volume were achieved. The PAMAM template can be feasibly removed by using water extraction.
THE APPLICATION OF DENDRIMER IN ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE PROCESSING
Daoxing Dai, Honghu Dai, Jintao Yang, Zhengdong Fei, Feng Chen, Mingqiang Zhong, May 2011
In this paper, poly(amido amine) (PAMAM) dendrimer, its lauryl quaternary ammonium salt and steary quaternary ammonium salt were used for blending modification of ultrahigh molecular weight polyethylene. The effects of modifiers on viscosity reduction, crystalline properties were investigated by torque rheometer, differential scanning calorimetry, X-ray diffraction analysis, etc. The results showed that three modifiers could decrease the melt viscosity of UHMWPE, which could be further explained from the view of distanglement.
ELECTRON BEAM IRRADIATION OF PP/EPDM BLEND: ULTRASONIC PREPARATION METHOD AND THEIR CHARACTERISTICS.
Jae-Kyoung Yang, Tae Yong Hwang, Phil Hyun Kang, Jae-Wook Lee, May 2011
Electron beam crosslinked PP/EPDM prepared by melt compounding has been developed. To improve the compatibility of blend, high intensity ultrasound is imposed during processing. The tensile strength increase continuously with increasing irradiation dose and elongation at break is decreased with radiation. Moreover, as compatibility of blend is enhanced, Youngƒ??s modulus, tensile strength and elongation at break also increased. Thermogravimetric analysis shows that thermal stability of PP/EPDM blend is enhanced with irradiation dose and improvement of compatibility. The improvement in the properties of blend is attributed to the enhanced compatibility and the formation of radiation induced crosslinking.
DEVELOPMENT OF REACTIVE BLEND WITH SUPERCRITICAL CARBON DIOXIDE
Tae Yong Hwang, Ki Hyun Park, Jae Wook Lee, May 2011
A reactive extrusion process for immiscible PP/PS blend with peroxide and multifunctional agent in the presence of supercritical carbon dioxide was studied. Supercritical carbon dioxide was used in reactive extrusion to assist the diffusion of agent into polymer matrix. The PP/PS blends were investigated by rheological measurement, scanning electron microscopy and thermal property. The results indicate that complex viscosity and storage modulus of blend are increased by adding peroxide and multifunctional agent. Moreover, analysis of the products revealed that the use of supercritical carbon dioxide led to improved compatibility.
THE STUDY ON GRAPHENE OXIDE AS A HETEROGENEOUS NUCLEATION AGENT IN SUPERCRITIAL CARBON DIOXIDE FOAMING
Minjie Wu, Jintao Yang, Honghu Dai, Feng Chen, Zhengdong Fei, Mingqiang Zhong, May 2011
Graphene oxide (GO) was prepared by oxidation of graphite using the Hummers method, and was modified by isocyanate to obtain dispersed GO sheets in dimethylformamide. Polystyrene (PS)/GO composites were prepared by solution blending, and their morphologies and properties were characterized. The addition of GO increased the glass transition temperature, storage modulus, and thermal stability of the composites compared with PS. Foams of PS and PS/GO composites were prepared by supercritical carbon dioxide foaming. The composite foams exhibited slightly higher cell density and smaller cell size compared with the PS foam, indicating the GO sheets can act as heterogeneous nucleation agents.
FEED ENHANCEMENT TECHNOLOGY FOR LOW BULK DENSITY MATERIAL INTO CO-ROTATING TWIN-SCREW COMPOUNDING EXTRUDERS
Paul G. Andersen, Maria Hoelzel, Thorsten Stirner, May 2011
Effectively feeding low bulk density material into a co-rotating twin-screw has always been challenging. With the introduction of even finer particle size fillers as well as new generations of reactor resins, the issue has become even more problematic. Unit operations within the compounding process where material is more susceptible to fluidization are: transfer from storage vessel to feeders, from feeder to twin-screw and within the feed zone conveying section of the extruder. This paper will review a new Feed Enhancement Technology (FET) that provides significant improvement for the introduction of fine particle / low bulk density materials into the extruder.
INTEGRATIVE SIMULATION OF THERMOPLASTIC PARTS BY TAKING INTO ACCOUNT MOLECULAR ORIENTATION
Christian Hopmann, Walter Michaeli, Thomas Baranowski, Markus Brinkmann, Barbara Heesel, May 2011
The mechanical properties of thermoplastic parts are greatly influenced by the inner properties of the material in these parts. In order to take into account their effects an integrative simulation approach has been developed at the Institute of Plastics Processing at RWTH Aachen University. This approach until now has been focused on the local distribution of the microstructure and crystallinity depending on the processing conditions. This paper deals with the enhancement of the simulation approach that leads to a consideration of the anisotropic effects of molecular orientation in thermoplastic parts.
A STUDY OF INJECTION MOLDING OF THE BARREL FOR THE OPTICAL LENSES
C.C. Lin, J.Y. Shie, W.H. Lin, R.Y. Yeh, May 2011
A study of the barrel for the optical lenses based on the design of experiments is presented. The barrel provides an installation space for lenses to assembly. Therefore the optical characteristic of the mini projector is dominated directly by the lenses and the barrel. In this study, we analyzed the effect of the part thickness on the warpage by commercial software and investigated the influences of the molding conditions on the part quality experimentally. The study provides a systematical way to predict in which area a defect lies and determine the optimal injection velocity and holding pressure through statistical experiments.
STUDY ON PREPARATION OF PP/PA6/OMMT NANOCOMPOSITES AND BATCH FOAMING PROCESS CONDITIONS WITH VIBRATION FORCE FIELD
Xiang-Fang Peng, Haoyang Mi, Huaxin Xia, Xin Jing, May 2011
The composites of polypropylene/polyamide-6nano-organ-montmorillonite (PP/PA6/OMMT) with superior comprehensive properties were prepared using PP-g-MAH as compatibilizer prepared by dicumyl peroxide/benzoyl peroxide. It was shown that the addition of PP-g-MAH and OMMT nanoparticles improved impact strength and tensile strength as well as melt strength. Microcellular batch foaming equipment with Supercritical CO2 was used to study the foaming conditions of composites including foaming temperature, rotor rate and vibration force. The results presented improved microstructures, uniformed distribution, and the enhanced density resulting from employing vibration force field to shear stress force field.
SIMULATION ON THE PART WARPAGE AND PHOTOELASTIC STRESS WHEN MOLDING DISCONTINUOUS-THICKNESS-VARIATION PARTS COMBINED WITH DIFFERENTIAL MOLD COOLING
Shia-Chung Chen, Yuing Chang, Ping-Shun Hsu, Sung-Wei Huang, Yuan-Jung Chang, CT Huang, May 2011
Discontinuous-Thickness-Variation (DTV) is used to interrupt the continuous shrinkage locally to minimize warpage. Matching of DTV with various mold temperature differences between the mold core and cavity sides was performed. The combined effect can be quantitatively described by a design guide chart. Case studies also verify its effectiveness. Simulations were conducted to calculate the neutral axis shift and the frozen layer thickness difference due to the unbalanced cooling. The analysis indicates that variation in thickness will pull the deviated neutral axis and photo-elastic stress due to unbalanced cooling back to the center line, leading to a significant part warpage reduction.
SYNTHESIS OF THE SILICA PARTICLES GRAFTED WITH POLY(IONIC LIQUID) AND ITS APPLICATION IN FOAMING OF POLYSTYRENE
Jintao Yang, Yan Sang, Feng Chen, Zhengdong Fei, Mingqiang Zhong, May 2011
Poly[2-(methacryloyloxy)ethyl]trimethylammonium tetrafluoroborate (P[MATMA][BF4]), as a novel poly(ionic liquid) for the strong absorption of carbon dioxide (CO2), is grafted to silica particles by using a surface-initiated atom transfer radical polymerization (ATRP). Silica particles modified by P[MATMA][BF4] (SiO2-P[MATMA][BF4]) play as nucleating agents to produce polystyrene (PS) foams using supercritical CO2 as a blowing agent. Compared with amino-functionalized silica particles (SiO2-NH2), SiO2-P[MATMA][BF4] exhibits higher heterogeneous nucleation efficiency in the foaming process. The morphology characterization indicates that PS/SiO2-P[MATMA][BF4] composite foams have higher cell density and smaller cell size than those of pure PS and PS/SiO2-NH2 composite foams.
INVESTIGATION OF THE THROUGHPUT OF A SINGLE-SCREW EXTRUDER TAKING INTO ACCOUNT PRESSURE VARIATIONS DURING A STEP CHANGE IN SPEED
Andre Korsmeier, Volker Schoppner, May 2011
Extrusion is used to continuously manufacture endless plastic products such as tubes, profiles etc. An essential aspect during the manufacture of semi-finished products is the products' uniform wall-thickness, whereby the manufacturing costs are decisively influenced. The material output is fundamentally influenced by both changing the operating points and from pressure variations in the extrusion process. On changing the operating point, a steady operating point is to be obtained as rapidly as possible in order to minimise the production of rejects. Moreover, a uniform wall-thickness is to be obtained by means of reducing the pressure variations in the extrusion process.
NEW DEVELOPMENTS IN FLAME RETARDANCY OF POLYOLEFINS
Sergei Levchik, Pierre Georlette, Yoav Bar-Yaakov, May 2011
Polyolefins are highly flammable and it is very difficult to flame retard them. Relatively high loadings of flame retardants are often used in order to achieve UL-94 V-0 rating in these polymers. ICL-IP has developed new flame retardant systems which allow overcoming many of these limitations. This paper presents results on flame retardant performance and physical properties of number of polyolefins flame retarded with highly efficient bromine based flame retardants, polymeric flame retardants and combination of bromine and mineral flame retardants. New data is also presented on phosphorus-based flame retardants for polyolefin films and sheets.
CONTROL OF TEXTURED IONOMER SURFACES
Xueyuan Wang, Robert Weiss, May 2011
Textured surfaces consisting of nanometer to micrometer-sized lightly sulfonated polystyrene ionomer (SPS) particles were prepared by evaporation of the solvent from a polymer solution cast onto silica. The structure of the particles and aggregates were controlled by the rate of solvent evaporation. The surface morphologies were consistent with spinodal decomposition mechanism where the surface first existed as a percolated-like structure and then ripened into droplets. The SPS particles resisted deformation after annealing at 140C for one week. Water droplets stuck to surfaces even when tilted 90 degrees, making them candidates for applications requiring high adhesive forces, such as cleaning robots.
PHENOMENON-ORIENTED PROCESS AND PART OPTIMISATION OF COMPLEX INJECTION MOULDED PARTS WITH THIN-WALLED MOULDED-ON HOLLOW AREAS (GITBLOW), TAKING INTO ACCOUNT THE RESIDUAL WALL THICK-NESS DISTRIBUTION
Elmar Moritzer, Thorsten Plugge, May 2011
In the GITBlow-process it is possible in a second stage to further inflate the hollow-area produced by gas-injection molding (GIT). In recent years, specific GITBlow-process-pheno-mena relating to the inflation of moulded-on hollow areas have been identified. On the basis of these findings, and with the help of developed methods, it is now possible to draw wide-ranging conclusions about the residual wall-thickness-distribution in the final part. Aim of this paper is to assign these process-phenomena relating to wall-thickness-distribution to their respective influencing parameters. By developing an analysis-methodology, this project sets out to derive and describe part-optimising principles concerning the result-ing wall-thickness-homogeneity.
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