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
STUDY ON MORPHOLOGY, CRYSTALLINITY, BARRIER AND MECHANICAL PROPERTIES OF PET NANOCOMPOSITE FILMS
Gowrishankar Srinivasan, David Grewell,, May 2010
Polyethylene terephthalate (PET) nanocomposite films were prepared by cast extrusion followed by stretching, using chill rolls. Tensile modulus, tear and puncture resistance of the cast films were measured in the machine (MD) and transverse (TD) directions. Differential scanning calorimetry (DSC) was used to study the effect of processing conditions on crystallinity of the products. Effects of draw ratio and clay content on the mechanical properties and on the oxygen permeability of the PET nanocomposite films were also evaluated.
INVESTIGATION OF PROCESSABILITY OF ZEIN BASED PLASTICS AND COMPOSITES
Gowrishankar Srinivasan , David Grewell, May 2010
The current market viability of petroleum based plastics is strong but may drop in the future due to international oil crisis accompanied by issues associated with disposal. This has already led to a thrust to develop bio-renewable and biodegradable plastics. One of the emerging contenders are plant based protein polymers such as soy protein and zein (corn protein).The paper reports on the extrusion molding and mechanical performance of zein based plastics and natural fiber composites. Different formulations of zein plastics with plasticizers and crosslinking agents were extruded and both injection and compression molded. Samples exhibited strengths of up to 12.7 MPa and a crosshead displacement extension value of 61% for different formulations respectively. In addition zein formulations were compounded with coconut and corn-cob fibers in various filler levels via extrusion. The injection molded composite samples had strengths upto 20 MPa.
INVESTIGATION OF PROCESSABILITY OF ZEIN BASED PLASTICS AND COMPOSITES
Gowrishankar Srinivasan , David Grewell, May 2010
The current market viability of petroleum based plastics is strong, but may drop in the future due to international oil crisis accompanied by issues associated with disposal. This has already led to a thrust to develop bio-renewable and biodegradable plastics. One of the emerging contenders are plant based protein polymers such as soy protein and zein (corn protein).The paper reports on the extrusion, molding and mechanical performance of zein based plastics and natural fiber composites. Different formulations of zein plastics with plasticizers and crosslinking agents were extruded and both injection and compression molded. Samples exhibited strengths of up to 12.7 MPa and a crosshead displacement extension value of 61% for different formulations respectively. In addition zein formulations were compounded with coconut and corn-cob fibers in various filler levels via extrusion. The injection molded composite samples had strengths upto 20 MPa.
THIRTY YEARS OF PC/ABS BLENDS IN THE PLASTICS INDUSTRY
Bruce Hager , Dieter Wittmann , Eckhard Wenz, May 2010
Innovative development has made blends of polycarbonate and ABS (PC/ABS) the largest selling polycarbonate-based blends in the world. The inherent cost/performance advantages of PC/ABS blends especially excellent processability and low temperature ductility have made PC/ABS a material of choice in automotive interiors and housings for business machines.Much of this growth has come about due to improvements in ABS and flame retardant technology. Development efforts continue to push PC/ABS blends into new nontraditional areas such as extrusion where its ability to thermoform like ABS makes PC/ABS an exciting candidate to replace FRP in large part applications.
POLYMERIC FILMS FOR SELECTIVE PERMEATION OF CO2 AND O2
H. Wang , V. Pethe , B. D. Freeman , A. Hiltner , E. Baer, May 2010
Polymeric membranes with high permeationselectivity for carbon dioxide (CO2) over oxygen (O2) wereprepared by melt-blending polyethylene oxide (PEO) with ethylene-co-acrylic acid (EAA) and also by layermultiplying coextrusion. The solid state structure and thermal behavior were characterized and the permeabilityof O 2 and CO2 was measured at 23 ?§C. Comparison ofblends and microlayers revealed that the high CO 2selectivity of PEO was most effectively captured when the PEO phase was continuous as in the microlayers or in the cocontinuous 50/50 melt blend.
POLYMER CARBON NANOTUBE NANOCOMPOSITE FOAMS: SYNTHESIS, PROCESSING AND PROPERTIES
Changchun Zeng, Nemat Hossieny, Chuck Zhang, Ben Wang, May 2010
Polymeric foams are one of the most widely used materials. Incorporating nanoparticles in polymeric foams offers several distinct benefits including morphological manipulation and nanoscale reinforcement. This work focuses on poly (methyl methacrylate) (PMMA) multiwalled carbon nanotubes (MWCNTs) nanocomposite foams prepared by using carbon dioxide as the foaming agent. PMMA CNTs nanocomposites were synthesized using anti-solvent process. In combination with surface functionalization, uniform dispersion of CNTs in the polymer matrix was achieved. The CNTs profoundly influenced the foam cell morphology and mechanical properties. In the presence of 1% carbon nanotubes, microcellular nanocomposite foam was prepared under moderate temperature and pressure (120 x C and 20.68 MPa). The microcellular foam exhibited exceptionally high cell density of 3.9 x 1010 cells / cm3 , an increase of over two orders of magnitude than the pure PMMA foam under the same foaming conditions. The cell size was reduced by ~85% to 2.7 ?¬m. The microcellular nanocomposite foam showed a synergistic increase in compressive modulus (>20%), strength (>70%) and strain at yield (>300%) over the pure PMMA foams prepared under the same foaming conditions.
PIEZORESISTIVE BEHAVIOR OF POLY (HYDROXYBUTYRATE VALERATE)/MULTI-WALLED CARBON NANOTUBES CONDUCTIVE COMPOSITE
Mahesh Gupta, May 2010
In this study, piezoresistive behavior of poly(hydroxybutyrate valerate) (PHBV)/multi-walled carbon nanotoubes (MWCNTs) composite has been discussed. Melt mixing technique was used to achieve maximum possible dispersion of CNTs in polymer matrix, as this process involves very high shear forces during mixing. The prepared composite shows gauge factor value of three which is very close to gauge factor value of conductive metals like copper and aluminum. Quasi-static and time dependent piezoresistance was investigated for the prepared composite. Environmental scanning electron microscopy was performed to observe dispersion of CNT in PHBV matrix.
MECHANICAL PROPERTIES OF MODIFIED STARCH FILLED POLY(L-LACTIC ACID)
Jiwen Wang , Wenge Zheng, May 2010
Starch with surface modification by grafting with polyethylene glycol (PEG) of different molecular weight (Starch-g-PEG) was developed and blended with poly(L-lactic acid) (PLA). Tolylene diisocyanate (TDI) was used as a coupling agent. The properties of PLA/Starch-g-PEG were investigated by tensile and impact testing, Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM). Significant increase in the elongation at break and impact strength of PLA/Starch-g- PEG blends without sacrificing the tensile modulus and strength at optimum PEG molecular weight range was obtained compared to those of PLA.
STERILE BARRIERS FOR MEDICAL DEVICES: FAILURE MODES AND MITIGATION
Adriana Knapkova, Libor Friedel, Bruce Dehning2, Jiri G. Drobny, May 2010
From sterilization to use, medical device packaging must provide a microbial barrier for the devices they protect. Reliability of this packaging is of the utmost importance since packaging materials must endure folding, rubbing, and a host of other mechanical and environmental stresses that can challenge the barriersƒ?? integrity. Pouches consist of flashspun high-density polyethylene (FS-HDPE) sheeting and laminates films composed of polyolefins and nylons. Case studies regarding sterile pouch failures that occurred at various stages of qualification testing and solutions for mitigating failures are presented. Common failure modes and mechanisms are discussed in detail.
AMT INVESTMENTS: MEASURING AND STRENGTHENING OF THEIR INFLUENCE ON COMPANYƒ??S PERFORMANCE
Adriana Knapkova , Libor Friedel , Bruce Dehning , Jiri G. Drobny, May 2010
Paper discusses research in progress which is focused on performance management and measurement with regard on Advanced Manufacturing Technologies (AMT) investments. The aim of the paper is to show new combinations perspectives and potentials how to see the impact of AMT in the chain of performance effects.Based on critical literature review and experience from different performance management cases we determined several ƒ??toolsƒ? - EVA BSC ABC/M and EFQM Excellence Model as a suitable and powerful concepts which can be used mutually for measurement and management of the companyƒ??s performance. The synergic effects of the above mentioned concepts are discussed and the influence of AMT investments on companyƒ??s performance is analyzed.
COLOR MATCHING OF WEATHERABLE CO-EXTRUDED FILMS
Antonio. J. Carrillo, A. I. Isayev, May 2010
Color matching of two-layer co-extruded films was performed by color compensation in either the top layer or bottom layer. With the former approach, excellent initial color match (??E<1.0) and weathering performance ??E~2.3 at 6,000kJ/m2 exposure) were achieved; however, a large color shift due to thickness variation (??E>3.0 at 50% thickness reduction) was observed. On the contrary, with the latter approach, poor initial color match (??E>4.0) and weathering performance (??E>3.0 at 6,000kJ/m2 exposure) were experienced; nonetheless, a very small color shift due to thickness variation (??E<1.0 at 50% thickness reduction) was produced.
BIREFRINGENCE IN GAS-ASSISTED INJECTION MOLDINGS: CONTRIBUTION OF THERMAL BIREFRINGENCE
Antonio. J. Carrillo , A. I. Isayev, May 2010
Various components of birefringence in polystyrene (PS) tubular moldings obtained by gas-assisted injection molding (GAIM) were simulated considering both flowand thermally-induced stresses using linear and nonlinear viscoelastic theories respectively. Flow birefringence components were calculated using the stress optical rule while thermal birefringence components were simulated using a photoviscoelastic model. Free quenching experiments in tubular and rod samples were performed and various components of birefringence were measured. The measured values were found to be in fair agreement with predicted results. Considering thermal and flow birefringence in simulations provides a better description of experimental results indicating that in GAIM moldings the birefringence near the mold wall and inner wall were caused mainly by flow and thermal stresses respectively.
BIREFRINGENCE IN GAS-ASSISTED INJECTION MOLDINGS: CONTRIBUTION OF THERMAL BIREFRINGENCE
Antonio. J. Carrillo , A. I. Isayev, May 2010
Various components of birefringence in polystyrene(PS) tubular moldings, obtained by gas-assisted injectionmolding (GAIM), were simulated considering both flowandthermally-induced stresses using linear and nonlinearviscoelastic theories, respectively. Flow birefringencecomponents were calculated using the stress optical rule,while thermal birefringence components were simulatedusing a photoviscoelastic model. Free quenchingexperiments in tubular and rod samples were performedand various components of birefringence were measured.The measured values were found to be in fair agreementwith predicted results. Considering thermal and flowbirefringence in simulations provides a better descriptionof experimental results indicating that, in GAIM moldings,the birefringence near the mold wall and inner wall werecaused mainly by flow and thermal stresses, respectively.
OPTIMIZATION OF MATERIAL FORMULATION AND PROCESSING PARAMETERS FOR WOOD PLASTIC COMPOSITE EXTRUSION
Yasuhiro Kawaguchi, Yoshiyuki Kosaka, Takeshi Nakachi, Hiroshi Kake, Jae Kyung Kim, Haruo Shikuma, Masahiro Ohshima, May 2010
The development of wood plastic composite (WPC) has facilitated the economical extrusion of profiles for various applications. The extrusion processing can be optimized by regulating the process temperatures, use of compatibilizer, lubricants and melt flow index of polymers. In this study, a rectangular WPC profile was produced from high density polyethylene (HDPE) and wood fiber (WF) with different extrusion conditions and material formulations using lab scale twin-screw extruder profile line. The influence of HDPE melt index, lubricant contents and processing parameters on extrudate quality and mechanical properties are discussed.
THERMALLY-EXPANDABLE MICROCAPSULES FOR POLYMER FOAMING – ITS EXPANDABILITY AND VISCOELASTICITY
Yasuhiro Kawaguchi , Daichi Ito , Yoshiyuki Kosaka , Takeshi Nakachi , Hiroshi Kake , Jae Kyung Kim , Haruo Shikuma , Masahiro Ohshima, May 2010
The thermally expandable microcapsule is a new type of blowing agent for polymer foaming. It has a core and shell structure. A low boiling point hydrocarbon liquid is encapsulated by the shell of acrylonitrile co-polymer. Mixing the microcapsules with the thermoplastic polymer and letting them thermally expand in the polymer can foam the polymer. In this study we developed a new microcapsule so that it can be used at high operating temperatures over 200 oC for foaming polypropylene (PP) by injection molding and extrusion. We investigated the effect of viscoelasticity of the shell polymer on the expandability of the microcapsule as well as on the surface appearance. The visual observation of batch foaming the rheological measurement and the experiments of foam injection molding and extrusion elucidated the existence of the optimal degree of cross-linking of the shell polymer that could realize the superior expandability and appearance at PP foam injection molding and extrusion.
THERMALLY-EXPANDABLE MICROCAPSULES FOR POLYMER FOAMING – ITS EXPANDABILITY AND VISCOELASTICITY
Yasuhiro Kawaguchi , Daichi Ito , Yoshiyuki Kosaka , Takeshi Nakachi , Hiroshi Kake , Jae Kyung Kim , Haruo Shikuma , Masahiro Ohshima, May 2010
The thermally expandable microcapsule is a new type of blowing agent for polymer foaming. It has a core and shell structure. A low boiling point hydrocarbon liquid is encapsulated by the shell of acrylonitrile co-polymer. Mixing the microcapsules with the thermoplastic polymer and letting them thermally expand in the polymer can foam the polymer. In this study, we developed a new microcapsule so that it can be used at high operating temperatures over 200 oC for foaming polypropylene (PP) by injection molding and extrusion. We investigated the effect of viscoelasticity of the shell polymer on the expandability of the microcapsule as well as on the surface appearance. The visual observation of batch foaming, the rheological measurement and the experiments of foam injection molding and extrusion elucidated the existence of the optimal degree of cross-linking of the shell polymer that could realize the superior expandability and appearance at PP foam injection molding and extrusion.
THE EFFECTS OF RESIDUAL STRESS AND CRYSTALLINITY ON RCP RESISTANCE IN PE-100 POLYETHYLENES
Christos P. Argyrakis , Patrick S. Leevers, May 2010
PE-100 pipe materials owe their excellent impact and brittle rapid crack propagation (RCP) resistance to ductile regions adjoining the inside and outside pipe surfaces. Slow cooling after extrusion seems to further toughen these regions by increasing crystallinity, but slow cooling also changes the distribution and magnitude of residual strain in the pipe wall and this may reduce the RCP driving force. This paper describes an experimental technique, which decouples these two effects and shows that crystallinity has less effect than expected. The effect of residual strain, meanwhile, is analysed using a semianalytical model of RCP, which indicates that its role may have been underestimated.
STUDY OF THE THERMAL ENDURANCE AND THE THERMAL DEGRADATION KINETICS OF A POLYPROPYLENE WOOD COMPOSITE
Makoto Seino, Manabu Nomura, Masaya Kotaki, May 2010
The thermal endurance and the thermal degradation kinetics of a Polypropylene wood composite are studied. The study is done by using several kinetics analysis methodologies including the following: conventional TGA, modulated TGA, Flynn-Wall-Ozawa isoconversional analysis (ASTM E1641-07), thermal endurance (ASTM E1877-05) and Friedmad isoconvertional method. The thermal degradation of the Polypropylene wood composite is compared with the thermal degradation of pure Polypropylene and wood powder. Despite of a discoloration process, the temperature peaks of wood decomposition for the composite and for the wood power are coincident. On the other hand, the temperature peak of Polypropylene decomposition for the composite is shifted to higher temperatures.
NOVEL AROMATIC POLYKETONE BLENDS WITH A NEW SILOXANE POLYETHERIMIDE COPOLYMER
Alejandro Londoño-Hurtad, Lena Marks, Gerhard Ziegmann, Tim Osswald, May 2010
New siloxane polyetherimide copolymers (SILTEM* resin) and aromatic polyketones form compatible blends across the composition range and exhibit superior mechanical, thermal and flame resistance properties. The exceptional properties of these blends make them suitable candidates for a wide range of applications including injection molded articles and electrical wire insulation. In particular, wire coatings made from these blends show excellent tensile elongation to break, high softening temperature, flexibility and good processibility and show promise for use in high temperature, halogen-free wire coatings and tubings.
FIBER JAMMING AND FIBER-MATRIX SEPARATION DURING KNITLINE FORMATION OF FIBER REINFORCED COMPOSITES
Alejandro Londoño-Hurtado , Lena Marks , Gerhard Ziegmann , Tim Osswald, May 2010
Knitline formation in the compression molding of sheet molding compound (SMC), a defect highly influenced by Fiber-Matrix separation, was studied through experiments and computer simulations.Square plates with meeting flow fronts where compression molded varying the initial mold coverage. In order to evaluate the influence of mold coverage on knitline development, tensile and three point bending tests of specimens taken from the meeting point of the flow fronts where performed.Mechanistic computer simulations of fiber suspensions where used to validate the experiments.
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