8:00 am – 11:30 am:
M3-Engineering Properties and Structure: Innovations in Polyolefins and Plastics
(Moderators: Teresa Karjala and Rajen Patel)-Room S320B
8:00 am – 8:30 am:
KEYNOTE: Innovation in Mature Markets: Understanding Global Trends across the Value Chain Key and Accelerating Development
Narayan Ramesh, Dow Chemical
Markets trends of cost reduction, sustainability & down-gaging drive the need for new and improved products. Development of such products requires a look across the entire value chain – an Asset to Market look. An emerging trend in the materials space is related to collection and management of data that enables knowledge creation. Management of this data and the knowledge generated is critical to accelerating research. This talk will focus on what is required for rapid product development, launch and knowledge transfer across a global organization to sustain market leadership. Key examples will be presented and will cover these trends.
8:30 am – 9:00 am:
Melt-mastication of Isotactic Polypropylene for Improved Thermal and Physical Properties
Brian Cromer, R&D, Arkema
A new polymer processing technique called Melt-Mastication (MM) is presented as a useful method to fabricate isotactic polypropylene (iPP) with improved thermal and mechanical properties. Melt-Mastication is a low temperature mixing technique that subjects molten iPP to chaotic flow at temperatures between the melting and crystallization transitions thereby promoting flow induced crystallization. The resulting iPP assumes an unusual morphology that is highly crystalline (57% crystal volume fraction), melts at a temperature 10.3 K higher than conventionally processed iPP, and demonstrates melt memory after annealing at 200 °C. The crystal morphology by polarized optical microscopy and atomic force microscopy appears to be comprised of largely disorganized lamellae, with possible ordering in local regions. Melt-Masticated iPP demonstrates greatly improved compressive modulus (+77%) and strength (+40%). The enhanced thermal and mechanical properties are attributed to aspects of the crystal morphology produced by MM.
9:00 am – 9:30 am:
Techniques to Measure Impact Properties of Polymers
Sean Teller, Veryst Engineering
Commercial applications of polymers have always included circumstances of impact, but it has been consistently difficult to measure the high rate response of thermoplastics, thermosets, elastomers, and foams. Designers require this information to properly prototype and ensure the impact resistance of products, yet the suite of characterization techniques remains incomplete. This paper presents various methodologies to evaluate the high strain rate (impact) properties of polymeric materials. The discussion examines the applicable range of strain rates by material and methodology, and discusses which techniques provide information within constraints of accuracy, repeatability, and ease of testing.
9:30 am – 10:00 am:
Ways to Enhance Thermoelectric Properties of Melt Mixed Polypropylene-carbon Nanotube Composites
Petra Pötschke, IPF Dresden
Melt-mixed polypropylene (PP) composites with singlewalled carbon nanotubes (SWCNTs ) were used as thermoelectric materials which can convert a temperature difference between the two sides of the material into a thermovoltage. The effect of SWCNT content on Seebeck coefficient (S), electrical conductivity, and power factor was studied. In order to enhance these values for p-type composites, several strategies were applied. These involve (a) variation of the SWCNT modification, (b) incorporation of a high S copper oxide, (c) variation of melt-mixing conditions, and (d) addition of an ionic liquid. To generate n-type composites, additives like polyethylene glycol (PEG) and a non-ionic surfactant polyoxyethylene 20 cetyl ether were simply added during the melt-mixing procedure, inducing a switching from positive to negative S values in the pressed films. Finally, two prototype thermoelectric generators using both, p- and n-type PP based materials, could be manufactured.
10:00 am – 10:30 am:
Analysis of Newly-Developed Textured PTFE Gaskets Subjected to Creep Relaxation
Ali Gordon, University of Central Florida
The ability of a gasket to maintain sealability over a long period of time is the primary consideration for pressure vessel and piping designers. While service conditions such as temperature, internal pressure, gasket stress, and the caustic nature of the transport media are all important parameters, factors such as the gasket material, gasket dimensions, and flange torque procedure have generally been viewed as the most influential. Viscoelastic gaskets are attractive as intermediate layers between bolted flanges because they conform to the inherent imperfections between mating flange faces. They display time-sensitive relaxation responses over the long term. Next generation gaskets, termed EPX and manufactured by Garlock, have been designed with a dual-face, raised honeycomb pattern to confer more rapid stabilization compared to existing non-textured products. Historically, a re-torque is conducted at approximately 24 hours after initial torqueing. The consequence of the secondary load is a significant boost in the load retention response, especially for more compliant materials. Preliminary studies reveal that the viscoelastic properties exhibited by ceramic-filled PTFE materials can achieve a nearly identical post-re-torque response with a one hour dwell in place of the day-long dwell. The gaskets having a textured-style (i.e., EPX), however, were found to require no re-torque whatsoever. Gasket efficiency, %, defined in earlier studies, is used to measure both stress relaxation and load carrying capability of gaskets. A design of experiments (DoE) approach is applied to characterize the factors that influence load relaxation response of the both candidate (EPX) and existing (Legacy) gasket styles. Experimental data are used to develop modeling constants associated with the Burger viscoelasticity model. With the use of finite element modeling, stress distributions within the gasket are revealed. The collection of efficiency measurement methods, approach to re-torque optimization, and modeling convey a novel framework that designers can invoke to facilitate improved flange performance.
10:30 am – 11:00 am:
Composition Dependent Charge Storage and EMI Shielding Performance of Thermoplastic Elastomer Nanocomposits Containing MWNTS
Shital Pawar, University of Calgary
This study demonstrates the charge storage and electromagnetic interference (EMI) shielding performance of thermoplastic polyurethane (TPU) based nanocomposites containing various amounts of conducting multiwall carbon nanotubes (MWNTs). The functional properties of TPU nanocomposites were systematically designed by generating various degrees of interconnected networks of MWNTs in the TPU matrix. The dispersion and interconnected networks of MWNTs were assessed using rheology and direct current (DC) conductivity measurements. An enhanced charge storage (i.e., high real permittivity) and extremely small loss (i.e., loss tangent) were achieved at a low fraction of MWNTs (5.0wt%) in X-band frequency, whereas, large elimination of incoming microwave radiation was achieved via highly interconnected networks of dielectrically lossy MWNTs.