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
MECHANICAL PROPERTIES OF INJECTION MOLDED THERMOPLASTIC POLYOLEFIN (TPO) CELLULAR FOAMS
Steven Wong , John Lee , Hani E. Naguib , C. B. Park, May 2010
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
Agustín Torres, Joel Bohórquez, Willian Noriega, May 2010
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
Agustín Torres , Joel Bohórquez , Willian Noriega, May 2010
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
Agustín Torres , Joel Bohórquez , Willian Noriega, May 2010
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
Penwisa Pisitsak, Rathanawan Magaraphan, Sadhan C. Jana, May 2010
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
Koffi L. Dagnon, Clark Robinson, Hua H. Chen, Nandika A. D’Souza, May 2010
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
Gheorghe Cojocariu , Chris Blubaugh , Douglas G. Hamilton, May 2010
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
Juan D. Sierra , María Noriega , Silvio Ospina , Elkin Cardona, May 2010
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
S. Sanchez , R. Ibarra , F. Solis , L. Cordoba, May 2010
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
Michael Heinzer , Myoungbae Lee , Rachel VanHouten , Ozma Lane , James E. McGrath , Donald G. Baird, May 2010
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
Shailesh Vidhate , Jaycee Chung , Nandika D’Souza, May 2010
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
Shailesh Vidhate , Jaycee Chung , Nandika D’Souza, May 2010
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
Koffi L. Dagnon , Nandika A. D’Souza, May 2010
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
Jun Tae Kang, Seong Hun Kim, Seung Goo Lee, May 2010
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.
THE EFFECT OF INJECTION MOLDING PARAMETERS ON THE PROPERTIES OF CARBON NANOTUBES FILLED THERMOPLASTICS
Fabian Rios, Amos Ophir, Samuel Kenig, May 2010
The electrical and mechanical properties of Polycarbonate and Polybutylene Terephthalate carbon nanotubes (CNT) nanocomposites were studied with respect to injection molding processing parameters, by means of design of experiments (DOE). Results demonstrated that the injection molding parameters had a significant effect on the properties of polymer/CNT nanocomposites. While the melt temperature had the most significant effect on the resulting volume resistivity, combination of parameters affected the mechanical properties of each polymer/CNT nanocomposite.
MULTI-COMPONENT TECHNIQUE: HYBRID PRIMARY FORMING OF PLASTICS PARTS WITH ELECTRICALLY CONDUCTIVE TRACKS
Walter Michaeli , Andreas Schreiber, May 2010
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
Walter Michaeli , Andreas Neuss, May 2010
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.
A SYNERGISTIC APPROACH TO IMPROVING ADHESIVE ADHESION TO STYRENIC COPOLYMERS AND THERMOPLASTIC ELASTOMERS
Walter Michaeli, Bernd Rothe, May 2010
Applications in the automotive, medical and electronics industries continue to drive improvements in polymer performance. Specifically, greater UV resistance, greater chemical resistance, higher service temperature, and processing stability are becoming more essential for consumer product components. Styrene-ethylenebutylene-styrene (SEBS) copolymer rubbers, SEBS/polypropylene blends, TPEs and polypropylenes are emerging as high performance materials integral to handles, grips, elastic components, oil gels for telecommunications, medical parts, automotive gaskets and hoses. TPEs in particular are being employed to replace plasticized low durometer PVC due to safety concerns as a component material for medical devices. The bond strengths of these polymers with specially formulated adhesives with and without atmospheric plasma surface modification were investigated. The results of bond strength improvement tests are presented.
POLYAMIDE 6-NANOCOMPOUNDS MADE VIA IN-SITU POLYMERISATION FROM CLAY AND CAPROLACTAM IN A TWIN SCREW EXTRUDER
Walter Michaeli , Bernd Rothe, May 2010
Layered silicates used as nano filler are suitable for improving the mechanical properties of polymers. As an alternative to melt compounding an in-situ polymerisation process for the production of PA6-nanocompounds is investigated. During the in-situ process the layered silicates are dispersed in the monomer caprolactam leading to an intercalation process. The following anionic activated polymerisation process itself takes place in corotating twin screw extruder. The production of a polyamide compound containing 0 2 and 4 wt.-% nano-scaled silicates was successful. The in-situ produced compounds were injection moulded and their mechanical properties were analysed.
Polyamide 6-Nanocompounds Made Via In-Situ Polymerisation From Clay And Caprolactam In A Twin Screw Extruder
Walter Michaeli , Bernd Rothe, May 2010
Layered silicates used as nano filler are suitable for improving the mechanical properties of polymers. As an alternative to melt compounding, an in-situ polymerisation process for the production of PA6-nanocompounds is investigated. During the in-situ process, the layered silicates are dispersed in the monomer caprolactam, leading to an intercalation process. The following anionic activated polymerisation process itself takes place in corotating twin screw extruder. The production of a polyamide compound containing 0, 2 and 4 wt.-% nano-scaled silicates was successful. The in-situ produced compounds were injection moulded and their mechanical properties were analysed.
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