SPE Library

Rice husk is a major biomass that is abundant, renewable and thus is promising material for the development of biodegradable polymers. The physical structure of rice husks between two different varieties of long grain rice has been evaluated in this study. The results show that the wall of the rice husk consists of 3 different layers with full and hollow fibers with different orientations. The fibers consist predominantly of cellulose and hemicellulose. Rice husk also contains about 10% moisture and about 20- 25% silica. The different varieties of rice husk have a similar structure, but different thicknesses of various layer and different diameters for the fibers. Silica is concentrated mostly in the outer layer and is the main reason why rice husks need to be modified before they can be used to develop biodegradable polymers or employed as reinforcing agents in other polymers.

The use of elastomer components in technical fields is enormously increasing. Elastomers can be used in a wide spectrum of applications including automotive-, machin-ery- and plant engineering, as well as in marine and civil engineering areas. Due to their properties regarding form-ability, workability, flexibility and adhesion, also the research activities are increasingly rising. In particular, the exploration of the aging behavior of polymers is getting more and more attention. With respect to literature, only a few experimental studies are dealing with the aging behavior of elastomers. Experience has shown that the properties of rubber materials can change significantly over time. The field of chemical aging is of particular importance due to the changes of the molecular structure and the cross-linking of the material during the aging process. These changes may in fluence a variety of properties such as weight, tensile and flexural strength. For more accurate predictions regarding the life time of an elastomeric component, all environmental factors need to be thoroughly experimentally investigated. In the light of these statements, more research activities concerning the long-term behavior of elastomers are nec- essary. This is the point where the present contribution attaches. We investigate natural rubber under different environmen-tal conditions. Therefore, we use air, seawater, distilled water, freshwater and salt solutions of 6%, 12% and 24%. The elastomer specimensare exposed to the medium and then aged by using different isothermal temperatures of 23°C, 60°C and 80°C. At predetermined aging times the samples are taken out of the medium and are experimen-tally investigated. Therefore, mechanical, calorimetrical and optical experiments are performed. The evaluated data is pointing out that the material is changing its properties during the aging time. Both soften-ing and stiffening effects can be observed relating to the environmental condition.

Modern injection mold manufacturing technologies allow internal cooling channels to be made to any shape that follow the precise geometry of the part in the mold. This aids in creating a uniform temperature distribution in the part by targeting hot spots on the part surface with arbitrary shaped cooling channels in the mold. Ultimately these result in better quality parts, shortened cycle times, reduced waste and cost reductions. Simulation of these processes requires a fully transient, three- dimensional (3-D), time dependent computational fluid dynamics (CFD) solution in these conformal cooling channels. This paper presents the further development of a (3-D) finite element based transient mold cooling simulation capability to include a solution for solving the 3-D flow in cooling channels. This new capability forms part of a future release of Autodesk Moldflow Simulation.

As we work to make our companies more sustainable, it’s necessary to evaluate not only ourselves but also those we select to help us achieve an improved “triple bottom line”. Our vendors and suppliers today will need to be collaborative partners tomorrow if we want to achieve more impactful financial, societal and environmental results. To evaluate a potential sustainable collaborator, consider a teachable, measurable and repeatable process that outlines the questions and judges the responses; then look for potential suppliers that have an observable culture of sustainable development and continuous improvement. You should be able to witness their culture in action when dealing with company officials and representatives. There are clear signs for companies with sustainable development cultures. When they are combined with a set of stewardship behaviors that drive sustainability, they make great suppliers. We have identified seven distinct stewardship behaviors that can be broken down into contributors to the Triple Bottom Line aspirations of every company focused on their on sustainable growth. For the environmental bottom line, consider “touch”; for societal goals, consider the behaviors such as “teach, treat and tout”; and for the profit driver, focus on behavior resources such as “time, talent and treasure”. These seven behaviors have attributes that can, and should be evaluated and measured as we chose our suppliers. In our presentation, we take a look at each separately to give us insight into the complete value a supplier can deliver.

Crosslinked plastic parts demonstrate prominent performance advantages over the non-crosslinked articles for a wide array of applications. New crosslinkable polyethylene compositions were recently developed which showed outstanding processibility and excellent thermal and mechanical properties, such as increased impact strength, high modulus, and enhanced environmental stress cracking resistance (ESCR). The advancement in balance of melt processibility and solid properties is ideally suited for the rotational molding process, opening opportunities to produce high-performance end-use products, including sporting boat, large agricultural and chemical containers, all-plastic cars, and other outdoor products.

ANTEC 2013 Technical Paper - Biodegradable and biomass base polymers are gaining attention from the view of environmental concern. In this report, novel poly (lactic acid) based multibranched polymers self-emulsified in 100 % water are described.

Due to the growing worldwide interest in tasks such as environment preservation and recycling, a model of float-valve system for domestic water tanks has been proposed. It considers in its design, the use of an urban waste product such as PET bottles, as the floating device of the mentioned mechanism, having as main idea to contribute with environment care. If the new design is compared with known commercial models, it could be considered as innovative due the reutilization of plastics wastes. At the same time, the system functionality is preserved, and the final parts are easy to fabricate at low cost. Also, the estimation of the Life Cycle Assessment (LCA) for the system shows that the proposed design could be catalogued as environmental friendly.

In recent years, the solar photovoltaic system has been attracted rising attention as an important power source in the viewpoint of environmental problems and other global issues. However, there are some problems in terms of durability of the each part. The back-sheet consisted of PET multi-layer films plays an important role to prevent moisture from outside into the main-board of the solar photovoltaic system. It is very important to investigate the durability of the back-sheet in order to maintain the usage of this system. In this research, we tried to evaluate the mechanical properties of PET films by applying the accelerated deterioration test. The durability was discussed on the basis of the results of the tensile test, the FT-IR measurement, and the SEM observation.

Biodegradable polymers are used to fabricate porous scaffolds for tissue engineering. Among different scaffold fabrication techniques, thermally induced phase separation (TIPS) is valuable because of producing highly porous scaffolds with interconnected structures. The effect of adding hydroxyapatite (HA) to poly (lactic-co-glycolic acid) (PLGA) scaffolds as well as other TIPS parameters was investigated in this study. The ultimate goal is to fabricate porous scaffolds that are mechanically functional, while they provide the desired porosity and pore interconnectivity for cell migration, cell growth, and transport of oxygen and nutrients.

There are some bio-based plastic films however some properties of the films should be modified to use as adhesive tape film and adhesive compound materials should be designed. We improved film properties by adjusting the sheeting process. Regarding the film, it was confirmed that poly lactic acid (PLA) film, which has good heat resistance and tear strength, was obtained by using the calendar sheeting process. On the other side, low glass transition temperature materials and crosslinking materials were selected and formulated for adhesive polymers. Developed bio-based adhesive tape was evaluated and compared to conventional acrylic adhesive tape, and comparable properties were obtained. In addition, in the case of surface protection tape, it indicated enhanced properties. We can introduce Eco-friendly Bio-based Adhesive Tape made from biomass materials.

The pressure-volume-temperature (PVT) behavior of Poly Latcic Acid (PLA) with dissolution of CO2 was investigated using an in-house visualization device; experiments were carried out at 453 K and 473 K, and pressure was varied from 6.894 MPa to 20.684 MPa. The results indicate that as the temperature increases, the swelling decreases, whereas an increase in pressure results in an increase in swelling. The effect of molecular weight (Mw) on swelling volume was also investigated by experimenting on different grades of PLA with varying Mw. The result is that molecular weight does not have a pronounced effect on swelling volume. The effect of talc on swelling ratio was observed by the addition of 5% talc content in PLA 3001D. A comparison was made between theoretical and experimental swelling volume ratios; the theoretical data was obtained using SS-EOS and SL-EOS.

Low density polyethylene (LDPE) was exposed to one hundred (100) consecutive extrusion cycles to simulate the process of mechanical recycling. Collected samples were characterized by means of melt flow index measurements and small amplitude oscillatory measurements to investigate flow properties. The results suggest that thermal degradation and gelation of LDPE occur after extensive extrusion which leads to simultaneous chain scission and crosslinking of the polymer chains. However, after 40 extrusions crosslinking is more dominant than chain scission. Rheological observations were confirmed by solubility studies that showed a pronounced increase in insoluble fraction after 40 extrusion cycles. This indicates that the technological parameters should be modified when processing recycled LDPE, particularly after 40 extrusion cycles.

Thermoplastic immiscible polymer blends were prepared from polytrimethylene terephthalate [PTT] and polyamide 6,10 [PA6,10] by melt processing in a Brabender mixer to assess morphology developed between the immiscible domains. PTT and PA6,10 were selected as a pair of engineering polymers with complementary properties and as a blend prepared to significant extent from bio-based precursors. Overall, a 50/50 blend of these polymers has a renewable content of nearly 50%. The overall objective is to develop an engineering blend with good stiffness, strength, and dimensional stability while simultaneously being easy to process. In the present phase of the work, blend homogeneity was studied as a function of mixing time and temperature in the range of t=0-25 minutes and T=240-260 C. Results are presented in terms of torque versus time and temperature curves that are interpreted in terms of domain formation and SEM micrographs are used to define domain size and overall morphology.

Jute fiber is of not only low density and good mechanical property but also natural and degradable property. On the other hand, recyclable Polypropylene (PP) was also good choice for environmental friendly material. Injection molding is one of the most important processes to manufacture plastic composites because it is of high quality products with low cost. However, weld lines are unavoidable when two separate melt fronts rejoin during injection molding. The presence of weld lines not only detracts from the surface quality but also significantly reduces the mechanical strength of injection- molded parts. Although it is not always easy to completely eliminate weld lines, the weld line strength could be improved through suitable adjustment of molding conditions such as melt temperature, mold temperature, hold pressure, injection speed, and so on. Therefore, in this paper the weld line property of injection molded jute/PP dumbbell shape specimen was investigated. Pultrusion technique was adopted to fabricate jute/PP long fiber pellets (LFT) and the re-compound pellets of LFT, i.e. RP was made to improve the fiber distribution. Then LFT, RP were used to mold dumbbell shape specimens with or without weld line. In particular, the influence of back pressure and holding pressure on weld line strength of injection molded jute/PP dumbbell shape specimens was discussed based on tensile test and SEM observation.

The effect of poly(butylene adipate-co-terephthalate) (PBAT) contents on crystallization and mechanical properties of poly(lactic acid) (PLA) and poly(butylene succinate-co-adipate) (PBSA) blend was studied. PLA and PBSA were blended in a twin screw extruder, which incorporated PBAT as a ternary component in PLA/PBSA blend. The ratio of PLA/PBSA was set at 80/20. The contents of PBAT were varied from 0 to 50 wt%. The thermal properties and crystallization behavior of PLA/PBSA/PBAT blends were analyzed by differential scanning calorimetry. The effect of PBAT contents on non-isothermal crystallization kinetic of the composites was investigated by using Avrami equation. Tensile modulus and tensile strength of the PLA/PBSA blends decreased when increasing PBAT contents. It can be noted that the addition of 20 wt% PBAT showed the maximum impact performance of the PLA/PBSA blends.

The packaging materials are spoiled in a short cycle. An environment packaging materials are demanded. The economic cost is one of problems to substitute general plastics for bio-resource sustainable plastics. In this study the potential of rice flour as compounding filler for sealant polymer was examined. Poly(butylene succinate)(PBS) / rice flour composite biodegradable film was processed directly by twin-screw extruder equipped with T-die. Heat seal property of the biodegradable film was investigated. As compounding filler material, the potential of rice flour on heat seal property was studied. At 100 ºC of heat seal temperature, the PBS / rice flour composite film showed high heat seal strength comparing with neat PBS film. By scanning electron microscopy observation, bled out rice flour grains at film surface affected heat seal property. The PBS / rice flour composite film could keep more than 80% tensile strength comparing with neat PBS. However heat seal strength for HDPE / rice flour composite film dropped. To attain high seal strength it needed longer dwell time. The compounded rice flour prevented heat seal property for HDPE. The exposed rice flour particles worked effectively for PBS / rice flour composite film.

Isothermal crystallization behaviors of poly (L-lactic acid) (PLLA) blended with different contents of Poly (D-lactic acid) (PDLA) were studied by wide-angle X-ray diffraction, differential scanning calorimetry and polarized optical microscopy. PDLA molecules added to PLLA formed stereocomplex crystallites in the PLLA matrix. The stereocomplex crystallites stayed unmelted at 190 °C and embedded in the PLLA molten matrix. Isothermal crystallization measurement at 100 °C revealed that the crystal radius growth rate decreased with an increase in the isothermal crystallization temperature. The spherulite growth rate has a peculiar PDLA concentration dependence. PLLA crystallization behavior might be affected by network structure and homogeneous dispersibility of stereocomplex crystal.

Recycled PET (RPET) is known to exhibit brittle behavior in the presence of notches. Therefore, we tried to improve the toughness and other properties of RPET by incorporating E-GMA, talc filler and engineering plastics as an impact modifier and talc to increase the rigidity and heat distortion temperature of RPET. As a result, these blends with E-GMA exhibited significantly higher stiffness and strength especially with increasing E-GMA content. In addition, these blends with talc filler indicated the high heat distortion temperature due to increase the crystalinity of RPET blends. Therefore, it was found that talc played an important role in enhancing the heat resistance of RPET. Some injection molding parts, i.e. tray, chopstick, and so on, were produced from these compound materials.

In this study, open cell foams were fabricated from blends of bio-based polymers to be used as sound absorbers. Different blends of Polylactide (PLA) with two grades of Polyhydroxyalkanoates (PHA) where foamed and characterized based on acoustic and mechanical performance. Rheological properties of pure polymers as well as their blends were studied to investigate the effect of material elasticity on the acoustic absorption of the resulting foams.

Conductive thermoplastic composite foams are a novel class of materials that can be an excellent candidate for producing cost-effective and lightweight products. In this work, electrically conductive polypropylene (PP) foams of various densities filled with varying contents of long stainless steel fibers (SSF) were successfully fabricated. The foaming of composites was achieved using a batch process and supercritical CO2 as the environmentally benign physical blowing agent. The PP-SSF foams maintained high level of electrical conductivity over a wide range of density reduction, depending on the initial loading of SSF. To better understand the conductivity behavior of solid and foamed composites, statistical percolation analysis was conducted. The analysis showed that the conductivity change with the foam density followed the percolation power law. The critical SSF concentration, calculated based on the sample’s final volume was 0.37 and 0.28 vol.% for the solid and foamed composites, respectively. In the current PP-SSF system, foaming decreased the weight up to ~70-80 % and lowered the percolation threshold by about 25%.