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.
CPVC Sprinkler Pipe in Contact with Suspected off-Ratio Urethane Foams
This paper discusses failures in a residential fire sprinkler system using CPVC pipe surrounded by sprayed urethane foam insulation. The pipe had multiple circumferential cracks. The external surface had a brown coloration in cracked areas. Chemical analysis showed presence of chemicals in the polymer consistent with components that may have been present in the foam. These chemicals had solubility parameters and boiling temperatures consistent with causation of Environmental Stress Cracking of CPVC. Accelerated exposure of strained CPVC pipe sections to three of these chemicals showed rapid formation of suspected environmental stress cracks.
Crystallization Characteristic and Heat Seal Properties of Biodegradable Films
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 and PLA/TPS blend films were heat sealed at heat sealed temperature of 90 and 100 °C. The heat seal time was varied from 0.5 to 2.0 s with a pressure of 0.2 MPa. The effect of heat sealed conditions on heat seal properties of PLA and PLA/TPS films was investigated. Heat sealed strength of PLA/TPS blend films decreased when increasing the heat sealed times. PLA/TPS heat sealed films exhibited greater crystallinity than the PLA heat sealed film, which characterized by crystallization kinetic study.
Curing Study of a Green" Thermosetting Resin"
A series of green" thermosetting resins oligomers of bis(hydroxyalkylene)-2-mercaptosuccinate has been reported recently . Curing in these thermosetting resins results from crosslinking via pendant thiol groups. As part of an effort to realize and assess the potential of these resins as sustainable materialsthe curing process was investigated using differential scanning calorimetry (DSC) and rheology. The progression of physical and mechanical properties such as the glass transition temperature (Tg) and the shear moduluswas monitored as a function of time and temperature. Tg of the resin was found to increase with curing and the averaged Tg of the fully cured resin was found to be 72.6 K ± 1.2 K higher than uncured resin. The increase in Tg corresponded with the change in rheological properties. The shear modulus obtained for fully cured samples reached a high modulus of 6.5 × 106 Pa at 200 °C. Additionallythe gel point was measured from the crossover of the storage and loss moduli. Based on the gel points the apparent activation energy of curing also was determined."
New Isosorbide-Polycarbonate via Interfacial Polymerization
Polymers based on aliphatic diols derived from bio-sources are of great interest in the plastics industry for the preparation of bio-derived products. Such products may show noticeable advantages compared to their oil-based counterpart such as biodegradability, biocompatibility and a low net environmental impact. The present paper discloses the synthesis and basic characterization of a new class of isosorbide-containing polyester carbonates.
Peelable - Resealable Films: FTIR Characterisation and Peel Strength
In the last decade, smart packaging has been an emerging field, which focuses on improving safety, ease of use and sustainability of food products. In this paper, enhancement in the ease of use is sought through the tailoring of a novel peelable-resealable structure. Therefore, multiple pressure sensitive adhesive (PSA) resins were first screened through by measurement of their peel strength. In light of the Fourier transform infrared spectrums, key properties of the peelable-resealable structure are discussed and material properties correlated to peel strength behavior.
Developing an Integrated Crash Simulation for Automotive Parts Produced from Natural Fiber Reinforced Plastics (NFC-Simulation)
The interest in renewable materials in car industry is growing dramatically. Natural fiber reinforced plastics (NFC) are an attractive solution, because of their interesting mechanical properties in combination to a good eco balance. One of the main obstacles to being used on a large scale in the car development process is the requirement that all components must proof that they meet product safety requirements and are fit for purpose through using CAE methods. The usage of CAE is a fixed established procedure in the automotive industry to meet today's challenging development times. The project NFC-Simulation, which is described in this paper, established a complete and integrated solution for the simulation of NFC components, from processing to crash simulation. In order to achieve these capabilities, many technical and scientific problems had to be solved in detail and the results integrated to a complete solution.
Poly (Lactic Acid)/Polyamide11/Cellulose Multiphase Systems
Nano crystalline cellulose (NCC) / PLA/bio-Polyamide11 (PA11) blends were prepared at different compositions by melt blending. A homogenous nano-scale NCC dispersion in PLA/PA11 blends was achieved. Both Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) reveal the localization of NCCs in both phases and at the interface. Also, the images show no significant changes in the morphology of the PLA/PA11 blends for up to 2 wt% NCC.
Development and Characterization of Bio-Based PA Composites for Electronic Packaging Applications Using Micro Fillers
Since electronic devices are constantly becoming smaller and more powerful [1,3], heat dissipation plays a very important role in electronic packaging applications. By using highly thermal conductive materials, it is possible to manage the heat dissipation on electronics to improve their efficiency. In addition, it is possible to avoid the use of mechanical fans by avoiding the heat sink cooling method. Thus, electronics can be made cheaper, lighter, and more compact [4-8]. Recycling of electronics is also another concern because millions of devices are used and produced every day. This research is aimed at making a polymeric composite that has high thermal conductivity, is electrically isolative, and is bio-based: a suitable as a replacement candidate for current electronic packaging materials. In this study, Polyamide (PA) with at least 60% bio-based content in composite with hexagonal boron nitride (hBN) was studied. Significant improvement in thermal conductivity was found relating to the size of conductive network, which has direct relationship with numbers, length, and direction of thermal pathways, rather than amount of filler particles.
Development of Hybrid Magnetic Nanoparticles Aimed to Collect Crude Oil in Aqueous Environments
Well-defined, magnetic shell crosslinked knedel-like nanoparticles (MSCKs) with hydrodynamic diameters ca. 70 nm were constructed through the co-assembly of amphiphilic block copolymers of PAA20-b-PS280 and oleic acid-stabilized magnetic iron oxide nanoparticles. These hybrid nanomaterials were designed as sequestering agents for hydrocarbons present in crude oil. Their combination of amphiphilic organic domains, for aqueous solution dispersibility and capture of hydrophobic guest molecules, with inorganic core particles for magnetic responsivity, make these nanomaterials uniquely qualified for oil spill remediation. The employment of these MSCKs in contaminated water resulted in the successful removal of the hydrophobic pollutants at a ratio of 10 mg of oil per 1 mg of MSCK. Using a magnet, the loaded nanoparticles were isolated and through “rinsing” in an ethanol sonicating bath, they were regenerated for reuse with no loss of their loading capacity.
Production of Bio-Based Polyethylene from Sugar Beets
A 22% solution of sucrose derived purely from sugar beets was dissolved in water and hydrolyzed with an invertase enzyme to produce glucose. This glucose was fed to champagne yeast and fermented to produce ethanol in yields of approximately 15 %. The ethanol was catalytically dehydrated to ethylene with a HZSM-5 catalyst in a small batch reactor. The ethylene was converted to poly(ethylene) using a Ziegler-Natta type catalyst. This poly(ethylene) should be suitable for use in plastic products like plastic bottles, containers, and grocery bags.
Properties of Co-Extruded Multilayer Packaging Films from Biopolyethylene and Milled Soy Flour
Multilayer packaging films from bio-polyethylene/soy flour composites were produced via co-extrusion processing through feedblock technology. Three layer films were produced containing up to 20% milled soy flour in the core layer, with neat polyethylene skins. Oxygen permeability of the films decreased by as much as 38% with the addition of soy flour to the core layer, but tensile strength values decreased by 29% in comparison to the neat multilayer control.
Reaction Extrusion of Polyurethane Based on Renewable Sources
This manuscript studies the reaction extrusion of polyurethanes based on both polytetramethylene ether glycol (C4) and polytrimethylene ether glycol (C3) polyols using a twin screw extruder. Polyurethanes (TPU) with hardness of 70A, 85A and 50D were fabricated. The two polyols showed comparable reaction kinetics with methylene diphenyl 4,4'-diisocyanate (MDI). C3 polyol polyurethanes showed slightly lower tensile stress at the same hardness level. But they showed comparable tear strength. C3 polyol TPUs needed slightly higher hard block to obtain the same hardness.
Recycled Polymers in Injection Molded PP Ridge Vents
Injection molded accessory products are widely used in residential and commercial roofing systems. These products generally require complex polymeric formulations to meet roofing functionality. With the growth of polymeric accessory products, significant post-consumer recycled streams are available. The goal of this paper is to discuss performance of several post-consumer recycled PP streams in injection molded PP formulations while maintaining performance attributes.
Effect of Nanoclay and Compatibilizer Content on Oxygen Permeability of LLDPE Nanocomposite Membranes
Layered-silicate-based nanocomposites offer great potential for improving barrier properties of polymer membranes for applications in packaging, protective clothing, geotechnical and environmental engineering, etc. In this study, organo-modified montmorillonite / linear low density polyethylene (LLDPE) nanocomposite samples with various percentages of nanoclay and maleic anhydride compatibilizer were prepared by twin-screw melt-extrusion followed by compression molding. Barrier properties are characterized through oxygen permeability measured according to ASTM D3985 standard test method. A linear relationship is observed between oxygen transmission rate and nanoclay percentage. Results reveal that both the nanoclay and compatibilizer individually contribute to the LLDPE nanocomposites oxygen permeability.
Effect of Nanoplatelets and Polymer Crystallinity on Moisture Diffusion through Polylactic Acid
Polylactic acid (PLA), a bio-derived biodegradable polymer, is being considered as substitute for conventional non-biodegradable polymers in packaging applications, among other uses. However, it has low barrier properties for gases and water vapor. In this work, the effect of nanoplatelets of nanoclay and graphene has been evaluated on the water vapor permeability through PLA films. In addition, the effect of PLA crystallinity has also been studied. It was found that while both nanoclay and graphene have a significant effect on the water vapor permeability, PLA crystallinity has only a smaller effect.
Effect of Photo-Oxidative Degradation on Environment Stress Cracking Behavior of Polycarbonate
The combined effect of two major causes of polymer failure, photo-oxidative degradation and environment stress cracking (ESC), have been investigated in this paper. Polycarbonate (PC) injection molded specimens were aged for 168 hours at 50 °C in an ultraviolet (UV) weatherable chamber. Then the stress relaxation and tensile tests were carried out in the ethanol environment to examine ESC behavior of PC. The results show that the tensile yield stress and stress relaxation resistance of PC improve slightly due to photo-oxidative degradation, while the ethanol will accelerate the failure of undegraded PC. When the previous degraded specimens were tested under the presence of ethanol, the stress relaxation rate increases significantly and the surface cracks appear to be more intensive in comparison with other ones. This indicates that there is a synergistic effect between photooxidative degradation and environmental stress cracking for PC injection molded parts.
Electrospun Protein and Polysaccharide Nanostructures to Improve Barrier Properties of Multilayer Systems Based on Polyhydroxyalcanoates and Biopolyesters
This work studies de effect of incorporating high barrier se lf-adhesive nanostructured interlayers of zein, pullulan and whey protein isolate between of polyhydroxyalkanoate (PHA) materials. Oxygen and water vapour barrier properties were greatly influenced by the morphology, thickness and inherent barrier of the electrospun interlayer materials. Thus, zein (in agreement with previous works) and pullulan formed fibrillar structures which significantly contributed to improve barrier properties of the multilayer systems. On the other hand, electrospun WPI formed bead microstructures and did not improve oxygen and water barrier properties of these multilayer systems. While the oxygen barrier properties was significantly improved by the presence of a zein nanostructured interlayer, the water vapour permeability of this multilayer system was seem to vary among materials since the zein interlayer was only efficient as a barrier element in the PHA materials as compared to polylactic acid (PLA).
Evaluating the Effects of Using Post Consumer Polyamide 6 (PCR-PA6) Resin for Automotive Component Application
Plastics consumption into various products has substantially grown over the years. Increasing resin prices and escalating environmental legislatives towards landfills are encouraging recycling of plastics. Recyclability of thermoplastic materials facilitates innovative application established on their residual contents. The plastic scrap thus is classified into predominant categories as postindustrial resin (PIR) and postconsumer resin (PCR). Postconsumer resin (PCR) is recovered from recycled products such as disposable packaging containers, bottles, and commodities in landfills. Discarded carpets are becoming a compelling source of PCR- Nylon resins. This paper evaluates the use of PCR-PA6 resin for automotive component application. The lifetime performance of these formulations was estimated through prolonged heat aging and testing at various intervals.
Evaluation of Natural Fiber Reinforced Recycled Polypropylene Composites
This paper examines the tensile strength and Izod impact behavior of natural fibers and wood particles in recycled polypropylene composites for injection molding. The initial round of testing compares the performance of the straight recycled polypropylene resin versus non-compatibilized natural fiber or particle composites, and then the different composite performance was indicated through the addition of a compatibilizer. The mechanical properties of natural fiber or wood particle and recycled PP composites without a compatibilizer were firstly compared with those of only recycled PP. Then, some natural fiber or wood particle and recycled PP composites using various compatibilizers were investigated. It was found that the elongation at break and the Izod impact strength of some natural fiber or wood particle and recycled PP composites using specific compatibilizer were indicated for high flexibility and adhesive formation as compared with some natural fiber or wood particle and recycled PP composites without a compatibilizer. The difference between natural fibers and wood particle was also discussed.
Experimental Analysis of the Material Degradation of PET on a Co-Rotating Twin-Screw Extruder
Plastics, starting from inexpensive mass-produced articles to technical high-end applications, are being used in ever more areas of life. The main drivers are their flexible product properties and the resultant broad application possibilities. To be able to offer plastic products inexpensively and conserve the environment at the same time, more and more attention is being paid to plastics recycling. Polyethylene terephthalate – in short PET – is of particular significance here because of its frequent application in the film and packaging industry and its special material properties. The recycling of PET, however, can only be carried out a limited number of times because it’s processing necessarily results in both thermal and mechanical stresses on the material. This is the basis for the reactions at molecular level, which result in a shortening of the molecule chains (material degradation) and exert a negative effect on the product properties. The aim of this study is to identify the factors that influence the material degradation of PET in twin-screw extrusion. To do this, various screw configurations and different speed and throughput conditions are examined in a series of experiments. Furthermore, material specimens are removed along the length of the screw in order to evaluate the influence of individual screw sections. By determining the intrinsic viscosity of the specimens, it is possible to measure the mean molecular weight and thus the material damage. Based on the test results, guidelines are drawn up for the compounding of PET so as to ensure as little damage as possible to the material.
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