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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Various topics related to sustainability in plastics, including bio-related, environmental issues, green, recycling, renewal, re-use and sustainability.
Fracture Behavior and Mechanical Property of Jute-Glass Hybrid Composite
Jute fiber has gained extensive use in recent years due to its advantage in environmental protection, low cost and low density. However, the limitation of its low mechanical property affects its application. Because of this reason, jute-glass hybrid fiber configuration was considered as an improvement. In this study, 2 kinds of jute-glass hybrid fiber configuration were employed to investigate the mechanical property and fracture behavior in different configuration. At the same time, different plies and different angle of the composite were analyzed. It was found the composite fabricated by B type fabric expressed better properties both on tensile and bending test. Scanning electron microscope observation was also found excellent matching between jute fiber and glass fiber in B type composite.
Halogen Free Polyphenylene Sulfide for Consumer Electronics Applications
The recent push for environmentally friendly halogen?free products has resulted in significant changes in the of polymer materials used in consumer electronics industry. A series of halogen free polyphenylene sulfide (PPS) products were developed to enable consumer electronics original equipment manufacturers and their suppliers to design and make products that will comply with halogen?free industry standards. These halogen free PPS products offer inherent flame retardancy (UL-94 V0), high flow suitable for small connectors, and high dimensional stability for metal over molding parts without loss of superior mechanical properties.
Heat Seal Characteristic of Environmental Friendly Films From Thermoplastic Rice Starch Filled Poly(Lactic Acid)
An environmental friendly biodegradable polymer film was prepared from poly(lactic acid)/thermoplastic starch (PLA/TPS) blend by cast film process at 0, 5 and 10 wt% of TPS. The PLA/TPS blend films were heat sealed by a heat seal tester at a heat bar temperature of 90 and 100 °C. The heat seal time was varied from 0.5 to 2.0 s with a constant seal pressure of 0.2 MPa. The effect of heat seal conditions on heat seal properties of PLA/TPS films was investigated. Heat sealed strength was carried out by peel testing. Differential scanning calorimetry was used to analyze thermal properties and crystallinity of the heat sealed PLA/TPS films. From the results, heat sealed strength of PLA/TPS blend films decreased when increasing the heat sealed times. PLA films was peelable at the heat sealed temperature of 90 °C. PLA/TPS heat sealed films exhibited greater crystallinity than the PLA heat sealed film.
High Performance Thermoplastic Vulcanizates Based on Natural Rubber by Electron Induced Reactive Processing
Electron induced reactive processing (EIReP) – an eco-friendly and sustainable reactive processing method based on the use of high energy electrons - was used for cross-linking of the elastomeric domain during melt mixing in order to prepare natural rubber (NR) and polypropylene (PP) based thermoplastic vulcanizates (TPVs). The electron treatment with various absorbed dose values showed a prominent effect on mechanical, rheological, and morphological characteristics of the PP/NR TPV. SEM and TEM studies confirmed that these TPVs can exist across the co-continuous or discrete phase morphology. The maximum set of mechanical properties (tensile strength of 15 MPa and elongation at break of more than 500 %) were obtained at an absorbed dose of 100 kGy for a 50/50 blend ratio of NR and PP without any addition of compatibilizer or chemicals. At higher absorbed dose values the degradation of polypropylene showed a negative impact on the mechanical properties of the TPVs. Depending on the morphology and the results of tensile test a structure-property co-relationship is drawn on the basis of common phenomenological understanding of the TPVs.
High Recycle Content PBT/PC Product Development
PBT/PC blends provide an excellent balance of chemical resistance, mechanical strength (especially at low temperature), and processability for a wide range of applications. Recently, appliance applications started to demand more sustainable, environmentally-friendly and green materials without sacrificing any properties for their new generation products. To respond to this market requirement, a high recycle content PBT/PC blend with excellent chemical resistance properties, good FR performance, and great mechanical properties was developed. The use of a high recycle based PBT/PC blend is the key to opening a new door to the more sustainable and green world for future appliance applications.
Impact Modification of PLA Using Biobased, Biodegradable Mirel PHB Copolymers
This work will focus on an approach to improve the impact toughness of poly (lactic acid) or PLA without compromising the biobased carbon content and compostability of PLA. Specifically, low-crystallinity and amorphous PHB copolymers were demonstrated to be very effective in improving the toughness of PLA at modest loading levels of 10-20 weight percent. This presentation will also compare the above approach with urethane, butadiene and acrylic impact modifiers along with the impact modification provided by other compostable polymers such as PBS and PBAT. Of particular significance is the extent of impact modification provided by an amorphous PHB copolymer (M4300 @ 10-20% loading) wherein the blend demonstrates a combination of mechanical properties that rival those of some engineering thermoplastics. Morphological considerations for the observed improvement in impact performance will also be highlighted.
Impact Of Crystallization On Performance Properties And Biodegradability Of Poly(Lactic Acid)
Polylactic Acid (PLA) is the most widely available, renewable and compostable polymer with several unique features. However, PLA is poor in its ability to withstand elevated use temperatures above 55 °C. As such it is common practice to either compound PLA with additives that improve its heat deflection temperature or increase its crystallinity in mold or in an extra annealing step for use in injection molded applications. The objective of this research was to study the crystallization of three PLA grades and its effect on thermal properties including compostability. Crystallization was studied using DSC and Talc was used as a nucleating agent. Crystallinity was found to vary from 25% to 60% for the various grades. The PLA was converted into test bars and cutlery and its heat distortion temperature was tested before and after annealing. Additionally, the crystallized cutlery was sent to a local composting facility and was found to disintegrate within 4 weeks, which is much sooner than the requirements of the ASTM D6400 standard of 12 weeks.
In Mold Coating of Thermoplastic Parts: Electrical Conductivity Versus Injection Pressure
In Mold Coating (IMC) has been applied to Sheet Molding Compound (SMC) as an environmentally friendly alternative to make the surface conductive; for subsequent electrostatic painting operations. Due to its successful application to exterior body panels made from compression molded SMC, the application of In Mold Coating for injection molded thermoplastic parts is being developed. In order to make the coating conductive, the filler used in IMC is carbon black (CB). However, the injection pressure needed to coat the part is significantly affected by the amount of CB in the coating material. Predicting injection pressures for IMC of thermoplastic parts is more critical than for IMC of SMC. To predict the coating pressures we need to measure the effect of CB on the IMC viscosity. In the present work, we studied the effect of CB on electrical conductivity and viscosity. The pressures needed for coating a typical IMC part with the required conductivity level are estimated.
Influence of Cooling Condition on Recycled PET Pellets
In this study we have developed “dry-less pellets”, which absorbs less moisture and do not require additional drying prior to molding. The developing technique namely “Hot Air cooling System” involves coolinging the strands slowly with hot air on a metal conveyor. This study was carried out to clarify a relationship between moisture absorption fraction and crystalline structure of dry-less recycled poly(ethylene terephthalate) (RPET) pellets. Two diffent cooling systems of extrusion processes were performed including water cooling method and hot air cooling syatem. The effect of hot air cooling temperature on properties of RPET pellets was investigated. Karl Fischer moisture titration, differential scanning calorimetry (DSC) and density measurement were used to characterize the pellets to determine the structures of the dry-less pellets. From the results, we have succeeded for preparing the “dry-less pellets” by controlling the hot air cooling temperature condition in the extrusion process. The crystallization process of RPET pellets is an important characteristic for the “dry-less RPET pellets”.
Investigation of Fracture in Polymers Using a Cohesive Zone Model
Polymers are increasingly being used for engineering structures and medical devices because of their excellent corrosion resistance and low cost compared with metals. However, the lifetime of plastics used in severe environments is significantly reduced due to environmental stress cracking (ESC). Current understanding of ESC in polymers is mostly empirical. In this paper, a methodology for investigating ESC in polymers is presented. The proposed approach, based on the cohesive zone model (CZM), is capable to characterize the degradation in the fracture zone explicitly, independent from the bulk material. In our preliminary investigation, the fracture on an elastic-plastic material was simulated, and the results were compared to a published paper. The simulation outcome indicates that the CZM is an effective tool to study fracture propagation in polymers under ESC.
Life Cycle Analysis of Various Paint Products Used In The Production Of Consume Products
In the Beckers organization sustainability has become a very important topic. It is a broad topic and from here we have been deriving areas of focus for our sustainability program. One vital step towards the pursuit of sustainable development would involve an in-depth look into the carbon exposure of the organizations’ value chain and operation. The Beckers organization undertook this activity by completing a life cycle analysis of our 4 major paint products that are commonly used in the production of mobile consumer products. This investigation was part of an initiative that was take with the support of The Natural Step, a nonprofit organization that provides support to organization committed towards sustainable development. The life cycle analysis was conducted within defined boundary conditions and had revealed that various paint technologies appear to contribute to varied levels of equivalent CO2 emissions.
Low Percolation Threshold and Improved Electromagnetic Interference Shielding Effectiveness of Polypropylene/Carbon Fiber Composites Through Foaming
Injection molding of solid and foamed polypropylene/carbon fiber (PP-CF) composites with different carbon fiber contents (0-20 wt. %) was conducted. ~ 25% void fraction in the foamed composites was achieved using supercritical N2 as the environmentally benign physical blowing agent. The effects of foaming on the percolation threshold, through-plane electrical conductivity, permittivity and electromagnetic interference shielding effectiveness (EMI SE) were investigated. Compared to the solid composites, in addition to the reduced weight of the polymer matrix (25%), introduction of foaming lowered the electrical percolation threshold from 17 wt. % to 11 wt. %. The relationship between the structure and electrical properties was explained in terms of the changes in the fiber orientation and skin layer thickness. At 15 wt. % CF content, the foamed composites yielded an EMI SE of about 25 dB, significantly higher than that of the solid composite (13 dB) with the same CF content. In both solid and foamed composites, the dominant EM attenuation mechanism was found to be wave absorption not reflection. The results reveal the application of injection foam molding technology to manufacture lightweight conductive products with lower fiber content and enhanced EMI SE.
Manufacturing of Polypropylene/Ground Tire Rubber Thermoplastic Elastomers by Ultrasonically Aided Extrusion
Compounding ground tire rubber (GTR) with thermoplastic polyolefins, such as polypropylene (PP), is a possible way to manufacture thermoplastic elastomers and also to recycle waste tires, thus solving a major environmental problem. The effect of ultrasonic treatment on the mechanical, rheological and morphological properties of PP and PP/GTR (ground tire rubber) blends in an ultrasonic single screw extruder (SSE) and an ultrasonic twin screw extruder (TSE) were investigated. PP and GTR was fixed at a ratio of 50:50. The treatment was carried out under amplitude of 5, 7.5 and 10 ?m, and at a flow rate of 2 lbs/hr. Pressure and ultrasonic power consumption were measured. Mechanical and rheological properties of untreated and ultrasonically treated PP indicated that TSE provided more degradation than in SSE. For 40 mesh blends from SSE, the mechanical properties improved with increasing ultrasonic amplitude. The viscosity indicated very little dependence on ultrasonic amplitude, which is evidence a formation of covalent bonds between PP and GTR. Viscosity of 140 mesh blends was lower than that of 40 mesh blends from both SSE and TSE, indicating a larger degree of degradation of blends with smaller rubber particle size. In addition, with smaller rubber particle size, much better elongation at break is obtained which indicates better adhesion between PP and GTR.
Material Optimization and Performance Evaluation of PolyVinyl Alcohol (PVOH) Films in Fresh and Salt Water for Decelerator Applications
Material optimization of biodegradable and water soluble polymers along with the influence of fresh and salt water conditions on the performance of polyvinyl alcohol-based films was examined for a U.S. Naval sonobuoy decelerator application. PVOH films of various thicknesses were produced on a manufacturing-scale lamination line using a solvent-based adhesive. Salt water and its temperature significantly influenced dissolution properties of the films. Mechanical properties of the as-received and laminated films were also examined and reported.
Mechanical Properties and Crystallization of Talc Filled Poly(Lactic Acid)/Poly(Butylene Succinate) Blend Composites
Poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) were blended in a twin screw extruder at various contents of PBS from 0-30 wt% with 0-20 wt% of talc by the extrusion process. The effects of PBS and talc contents on crystallization behavior and mechanical performances of PLA/PBS talc composites were investigated. The non-isothermal crystallization of the PLA/PBS/talc composites was carried out by a differential scanning calorimetry. The mechanical performances of the composites were investigated by tensile and impact testing. The incorporation of talc increase tensile modulus and perform constantly impact strength of the composites. In this study, the relationship between crystallization behavior and mechanical property was also elucidated.
Mechanical Properties of High Density Polyethylene - Pennycresss Press Cake Composites
Pennycress press cake (PPC) is evaluated as a bio-based fiber reinforcement. PPC is a by-product of crop seed oil extraction. Composites with a high density polyethylene (HDPE) matrix are created by twin screw compounding of 25% by weight of PPC and either 0% or 5% by weight of maleated polyethylene (MAPE). Tensile, flexural, and impact properties are assessed from injection molded test specimens. An improved PPC bio-filler was produced by solvent treating PPC (STPPC). Composite blends composed of STPPC were superior to their PPC counterparts. Composites made with STPPC and MAPE had significantly improved tensile and flexural properties compared to neat HDPE.
Melt Compounding of Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) / Nanofibrillated Cellulose (NFC) Nanocomposites: Properties and Solubility of Carbon Dioxide
Biodegradable nanocomposites were prepared using nanofibrillated cellulose (NFC) as the reinforcement and poly (3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV) as the polymer matrix. PHBV powder was dispersed in water, mixed with an aqueous suspension of NFC fiber, and freeze dried. The resulting PHBV/15 wt% NFC was then used as a masterbatch in a subsequent melt compounding process to produce nanocomposites of various formulations. Its properties, such as mechanical properties, crystallization behavior and solubility of carbon dioxide (CO2), were evaluated. Scanning electron microscopy (SEM) images revealed that individual fibers with diameters less than 1 ?m were still clearly distinguishable even though some of the NFC agglomerated. Adding NFC increased the tensile modulus of the PHBV/NFC nanocomposites nearly twofold. Differential scanning calorimetry (DSC) analysis showed that the NFC served as a nucleating agent, promoting the early onset of crystallization. However, high NFC content also led to greater thermal degradation of the PHBV matrix. The solubility of CO2 in the PHBV/NFC nanocomposites decreased and the desorption diffusivity increased as more NFC was added.
Modification of PVC with bio-based PHA rubber. Part 2.
Blends of biobased polyhydroxyalkanoates (PHAs) with PVC have been developed and demonstrated very unique properties when added between 5 and 30 phr. These blends promise to improve both mechanical and environmental performance of PVC. The breakthrough is based on the miscibility of PHA and PVC resins and similar processing windows. Based on the miscibility and performance requirements, specific compositions of PHA copolymers were created to improve plasticization, impact and processing modification. In impact modification, PHA rubber copolymers outperform the best available MBS core/shell impact modifiers and do not compromise PVC transparency and UV stability. In plasticization, PHA copolymers perform as high molecular weight, readily dispersible plasticizers and enable formulation of compounds with low additive migration, low extractables, volatile loss and staining. As a processing aid, the metal adhering properties of PHA copolyesters promote homogeneous shear melting of PVC particles and prevent overheating and degradation. It will be shown that due to their multifunctional performance, the PHA modifiers could significantly simplify the formulation of PVC compounds and reduce the overall amount of required additives. The PHA rubber copolymers are commercially biosynthesized by fermentation technology from renewable resources. They satisfy requirements on sustainability and biodegradability.
Molecular Structure and Thermal Properties of Recycled and Virgin Nylong and Their glass Fiber Reinforced Composites
The effects of molecular weight and molecular structure on non-isothermal crystallization behavior of recycled and virgin nylon and their composites with glass fiber (GF) were studied. Two different recycled nylon resins,namely post-industrial waste (PIW) and post-consumer waste (PCW) were used. The former was obtained from a fiber manufacturer and the latter was recycled from used carpets. Intrinsic viscosity (IV) measurements and 13carbon nuclear magnetic resonance (13C-NMR) were used to characterize the molecular weight and the structure of the resins. Non-isothermal crystallization of the resins was studied using differential scanning calorimetry (DSC). The molecular weights of recycled materials (without glass fiber) were found to be higher than that of virgin PA6, but their crystallization rates (implied by the reciprocal of t1/2) were faster. It is due to their higher cis conformer content and consequently advanced segmental mobility. Recycled materials contain TiO2 which can act as heterogeneous nucleating agent.
Natural fiber Composites for low cost automotive systems
The objective of this study is to develop a polymer matrix based composite technology for its use in low cost mass transit (automotive) System, considering the matrix/fiber compatibility, stiffness, strength, hardness, damping and moisture absorbance characteristics of Natural fiber Composites. This objective is achieved through formulation of a low cost composite material which meets the required demands for mass transit system and identifying the most economic manufacturing/fabricating process to produce components to be used in mass transit systems as the next crucial step. For manufacturing continuous laminate, commonly used reinforcement materials such as glass fiber as well as new materials such as natural fibers including, grass, bamboo and jute will be investigated in this study. Both hand layup and RTM method using unsaturated polyester resin matrix were used to fabricate continuous fiber laminate. The mechanical properties are measured and compared with respect to the reference material glass fiber composites manufactured through compression molding process. The investigation shows that Natural fiber Composites have mechanical properties as high as glass fiber composites or even higher in some cases. The effect of water absorbance in the case of natural fibers on their mechanical properties was also determined. Such good mechanical properties in combination with light weight and lower cost, makes the use of these natural fiber composites very attractive for low cost mass transit (automotive) industry. The composite performance is analyzed in terms of constituent properties and product quality.
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