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.
|= Members Only|
Various topics related to sustainability in plastics, including bio-related, environmental issues, green, recycling, renewal, re-use and sustainability.
The Blends of Polypropylene (PP) with Functional Polyolefin Elastomer (FPOE) for Recycling of Xerographic Toners
This paper presents experimental results on the blends of polypropylene (PP) with functional polyolefin elastomer (FPOE) for recycling of xerographic toners. All experiments were carried out in a co-rotated reactive twin screw extruder. The investigation of the mechanical properties and morphology for different blends consist of PP, xerographic black toners and functional POE (FPOE) through reactive compounding. It is of interest to note that the notched Izod impact resistance of the blends with functional POE (FPOE) is significantly improved relative to physical blends. However, tensile strength at yield (?y) and modulus of elasticity (E) of the reactive blends are reduced. The reason why the impact properties should be so is clearly shown by the stress-strain behavior of the blends. Morphology of the cryogenic fracture surfaces of the blends was studied through scanning electron microscopy (SEM). The results of morphological studies indicated that not only the domain size of the phase of black toners could be reduced but also the interfacial adhesion could be enhanced through proper functional POE (FPOE). The phase morphology of the blends also illustrated that better dispersion of black toners could be obtained through using FPOE whereas serious agglomeration of black toners was found in the physical blends. It is elucidated that the functional POE could be an excellent candidate of compatibilizer for recycling xerographic black toners.
The Carbon Dioxide Technology Platform
What if the electronics industry used specially designed photoresists that could be deposited using a spin coating process based upon liquid CO2 instead of organic solvents? Also what if this industry didn’t have to use hundreds of millions of gallons of water per day to remove sub-micron particles during the manufacture of integrated circuits and flat panel displays? Imagine polymerizing monomers in a continuous stirred tank reactor with the resulting polymers instantly dry, avoiding the trillions of BTUs needed every year to dry commercial polymers made in aqueous reaction media. Imagine an automotive industry that doesn’t expose its employees to toxic chlorinated solvents during metal degreasing processes. Imagine a textile industry that doesn’t need to use 100 lbs of water for every 1 lb of yarn that was dyed. Imagine local dry cleaners that don’t need to clean garments in perchloroethylene and local businesses that don’t need to pay exorbitant, newly enacted taxes on solvent use or carry newly mandated liability insurance policies. What if the demands on municipal water systems and municipal waste water systems could be dramatically reduced by changes in manufacturing technology? Imagine an educational environment where students become grounded in the fundamentals of their core disciplines, are exposed to cutting-edge, multidisciplinary science, and can experience the satisfaction and excitement that comes from doing research that makes a difference to society. The discussion will focus on the latest developments from the NSF Science & Technology Center for Environmentally Responsible Solvents and Processes. In particular, the detailed synthesis and CO2 solution properties of fluorinated and siloxanebased homopolymers and block copolymers will be discussed. The utility of such macromolecules will also be demonstrated for use in coatings (photoresists and textiles), separations, stabilizers for polymerizations, and scaffolds for catalysis. Particular attention w
The Effect of Residual Impurities on the Rheological and Mechanical Properties of Engineering Polymers Separated from Mixed Plastics
This paper reports the results of an investigation of the effects of purity level and nature of impurities on the properties of recycled polycarbonate and recycled acrylonitrile-butadiene-styrene polymers blended with the corresponding virgin resins. The relevant thermal, mechanical and flow properties were measured. It is concluded that properties of recycled polymers depend not only on the amount of impurity present but also on the kind of impurities and contaminants that are present. The latter factor even plays an important part in relation to compatibility of polymers. However, polymer melt rheology seems less sensitive to impurities than some mechanical properties such as impact strength. More than 99% purity is needed for recycling these polymers back into their original, high-value applications.
The Role of Testing in the Failure Analysis of Plastics
Failure analysis (FA) of products and materials always requires careful observation of the general circumstances involved. The product failure analyst never overlooks external causes or environmental effects. All FA also requires a healthy dose of common sense and a 'Sherlock Holmes' investigatory sense. However, specialized material and product tests are also essential components of successful FA including: material mechanical properties, tests for composition and uniformity, residual stress tests, tests for contamination, identification and quantification of residual solvents, microstructural examination, and many more. An overview of general FA techniques will be presented, followed by specific examples of plastic FA. These specific examples will be discussed in detail, with special emphasis on the key findings derived from specialized laboratory testing. Examples will include plastic piping systems, consumer products, industrial equipment, and sporting equipment. Techniques discussed will include residual solvent identification by GC/MS, various spectroscopic techniques, optical and electron microscopy, thermal analysis, and mechanical properties testing.
Thermal Analysis of Blends of Recycled HDPE and Virgin Polyolefins
This paper investigates the melting point and crystallinity behaviour of blends of recycled milk bottle HDPE with injection moulding and film blowing grade high density polyethylene (HDPE), linear low density polyethylene (LLDPE) and low density polyethylene (LDPE) as part of a larger investigation into blends of recycled HDPE and virgin polyolefins. The variation in melting points and crystallinity levels for blends of recycled HDPE with either HDPE or LLDPE were linear with composition, and displayed only one melting point, while recycled HDPE with LDPE displayed separate melting points for each compositional component.
Vibration-Assisted Injection Molding Applied to Recycled General Purpose Polystyrene
Because of their previous thermal and shear history, recycled plastic materials have properties that are significantly inferior to those of their unrecycled counterparts. Thus, the applications of these materials are limited. With the aid of Vibration-Assisted Injection Molding (VAIM) technology, during the present study the properties of products made from recycled polymeric materials were improved. In this paper, the property enhancements realized with recycled polystyrene are presented compared with those obtained through the convention injection molding of virgin material. Also, a potential theoretical basis for the phenomena is discussed.
VOCs Emissions and Structural Changes of Polypropylene during Multiple Melt Processing
Polypropylene, as a commodity recyclable thermoplastic, is studied in this research to evaluate the potential environmental impact resulting from volatile organic compounds (VOCs) emitted during multiple reprocessing. Unstabilized commercial polypropylene (PP) grade was processed several times by injection molding. Samples were examined after each cycle for total VOCs emissions with a flame ionization detector (FID) and cumulative VOCs emissions were obtained after each processing step. Corresponding structural changes were investigated with Fourier Transform Infrared (FTIR) Spectroscopy and results were correlated with rheological data that showed decreasing viscosity particularly after the 7th processing cycle.
Waste Management of PET Bottles in Croatia
Waste management is gradually becoming a priority within an integrated approach to nature conservation. Croatia has taken a number of good steps during the recent years. The first life-cycle and economy analyses in Croatia were made for managing of glass waste in 1997, but no serious study of plastic waste was made until recently. Among all types of plastic waste, only PET-bottles are collected in Zagreb (within the OHO system - Croatian Recycling System), so it was logical to make the first life-cycle analysis of PET-bottle. The results have shown the evaluation of PET-bottles' impact on the environment and the critical points" of PET-recycling were pointed out."
Weathering Effects on Mechanical Properties of Recycled HDPE Based Plastic Lumber
Commingled recycled plastic lumber (RPL) decking was exposed to the environment for eleven years. The weathering effect is examined by performing mechanical property tests on the full size deck boards before and after the exposure. Flexural tests on the weathered deck boards were conducted with the exposed side and the unexposed side tested in tension. The flexural properties after weathering are compared to the original flexural properties. These data show the effect of weathering on recycled high-density polyethylene based RPL. A life cycle cost analysis (LCCA) is also presented to compare the cost of a wood deck versus an all RPL deck. The purchase, maintenance, and disposal costs are included.
Bio-Composite Materials as Alternatives to Petroleum-Based Composites for Automotive Applications
Natural/Bio-fiber composites (Bio-Composites) are emerging as a viable alternative to glass fiber reinforced composites especially in automotive applications. Natural fibers which traditionally were used as fillers for thermosets are now becoming one of the fastest growing performance additives for thermoplastics. Advantages of natural fibers over man-made glass fiber are: low cost low density competitive specific mechanical properties reduced energy consumption carbon dioxide sequesterization and biodegradability. Natural fibers offer a possibility to developing countries to use their own natural resources in their composite processing industries. The combination of bio-fibers like Kenaf Hemp Flax Jute Henequen Pineapple leaf fiber and Sisal with polymer matrices from both non-renewable and renewable resources to produce composite materials that are competitive with synthetic composites requires special attention i.e. biofiber- matrix interface and novel processing. Natural fiber reinforced polypropylene (PP) composites have attained commercial attraction in automotive industries. Needle punching techniques as well as extrusion followed by injection molding for natural fiber–PP composites as presently adopted in the industry need a “greener” technology-- powder impregnation technology. Natural fiber–PP or natural fiber–polyester composites are not sufficiently eco-friendly due to the petro-based source as well as non-biodegradable nature of the polymer matrix. Sustainability industrial ecology eco-efficiency and green chemistry are forcing the automotive industry to seek alternative more Eco-friendly materials for automotive interior applications. Using natural fibers with polymers (plastics) based on renewable resources will allow many environmental issues to be solved. By embedding bio-fibers with renewable resource based bio-polymers such as cellulosic plastic corn-based plastic starch plastic and soy-based plastic are continuously being developed at Michigan S
Polyester Resin System Utilizing Renewable Sources - Soybean and Corn
A resin that utilizes 25% grain-derived organics has been developed. Ethanol and soybean oil are reacted with other materials to produce a durable polyester resin capable of equal or better performance than current polyester resin systems. Utilizing the sheet molding compound (SMC) molding process this unique renewable-source polyester resin has successfully produced large combine parts for use in the agriculture industry. The transportation industry is investigating this resin for use on upcoming vehicles.
Development of Low Density GMT Composites for Automotive Applications
The development in the field of composites has been spurred by the need for lightweight fuel-efficient automobile that is environmentally friendly and affordable. A low density light weight GMT composite containing long chopped fiber strands was developed by AZDEL Inc. for use in headliner and other automotive applications. The low density GMT (LD-GMT) is available in grades ranging in basis weight of 600 to 2000 g/m2. This paper presents development of this LD-GMT material for automotive interior and structural applications. This thermoformable material has several advantages over other traditional materials like steel and thermoset composites. The LD-GMT offers design flexibility low weight high rigidity excellent energy absorption characteristics faster cycle times and an environmentally friendly manufacturing process. The design flexibility and application of these LD-GMT composites in automotives and the advantages of applying these composites over the other materials in interior structural and modular applications will be discussed.
A Plasticating Screw Design for the Reprocessing of Multi-Layer or Multi-Material Plastic Formulations
Recycling or reprocessing of “multi-layer” or “multi-material” plastic products is a particular problem for plastic compounders or recyclers. Examples of multi-layer plastic products include painted or coated plastic items, such as automotive body panels, or multi-layer plastic packaging, such as that used in high barrier applications. In each of these cases, the coating or multi-layer structure is utilized to enhance either the product's overall performance or appearance. Unfortunately, the presence of other material layers will generally have a negative impact on the recyclability of the primary thermoplastic material as they often act as incompatible contamination. For example, most of the paints or coatings used in the automotive industry are thermosetting in nature and act as solid particulate inclusions in the recycled matrix material. Methods to remove coatings from coated plastic parts have been developed, but are not always cost effective. As an alternative, these complex material constructions can sometimes be effectively recycled if the contaminating layers can be reduced in particle size and effectively mixed into the continuous thermoplastic matrix material. A single screw mixing or “grating” section has been designed and evaluated experimentally in this study. Experimental trials were conducted using reground, painted thermoplastic olefin automobile bumpers. The reground bumper scrap was extruded using a single screw equipped with this grating sections, and several more conventional extrusion screw designs. The paint flake size distribution of the extrudate, and the physical properties of samples molded from the extrudate were evaluated for each screw design, both with and without melt filtration.
Application of Thermoplastic Elastomer Material Testing Data for Automotive Body Seal Analysis
Material recycling requirement gradually opens the automotive body sealing market to thermoplastic elastomers (TPE), which is primarily dominated by EPDM thermosetting elastomers. Due to special material behaviors of elastomers, careful attentions should be taken when analyzing the body seal performance using material testing data, especially for TPE materials. This paper will address some of the issues by analyzing body seal products using TPE materials. The general guidelines for body seal analysis and result evaluation will also be discussed.
Acrylate Elastomer Modified Polyolefinic TPEs
Soft polyolefinic TPEs are increasingly being favored over PVC based TPEs for automotive interiors. The major drivers for this change are the recycling and environmental aspects of PVC. Some strengths of polyolefinic TPEs are good low temperature performance, retention of properties after exposure to sunlight and high temperatures, low fogging, and little or no odor. The challenges in switching from PVC to polyolefinic TPEs involve attaining the desired melt processing characteristics and the mechanical and aesthetic properties at a relatively low cost. This paper will discuss Eliokem's use of a specialty acrylate elastomeric modifier in designing polyolefinic TPEs for automotive interiors and other applications
Analysis of Carpet Recycle Streams Using Differential Scanning Calorimetry, Thermogravimetric Analysis and Gas Chromatography
In order to make an injection moldable product with consistent properties from recycled carpeting, quantitation of the polymeric and non-polymeric components of the carpet feed stream is required. Feed mixtures containing nylons, polypropylene and PET as well as latex and calcium carbonate from backing material have been studied. A combination of DSC and TGA measurements is shown to provide compositional data on both polymeric and non-polymeric components in a rapid and inexpensive manner. More exact determination of polyamide components is accomplished using hydrolysis and derivatization to prepare samples for gas chromatography.
Analysis of Silicone Polymers at Trace Levels by Pyrolysis Gas Chromatography/Mass Spectroscopy
Silicone polymer release liner surfaces on paper, for self stick stamps and labels, become contaminants in paper recycling. Low print adhesion is one major problem limiting the inclusion of silicone release liners in recycling feed stock. A very sensitive method of analysis of silicone polymer during and after recycling employs pyrolysis GC/MS. The analysis provides a measure of siloxanes, ignoring inorganic silicon compounds such as silicates. The method also distinguishes between linear and branched polysiloxanes by different pyrolysis products. High sensitivity, to ppb, may be possible using single ion monitoring or selected ion data collection of mass spectra.
CAPE-VIT - A Different View of Education in Plastics Design
Education for the growing needs of the plastics industry is recognized as needing a different approach that will enable a quicker integration of the graduates in the working world. Under the auspices of the EU programme Leonardo da Vinci a group of universities and institutions developed a course programme and structure for preparing engineers with skills for plastics design and processing with a sound awareness of the environmental issues. Specific characteristics of the course are the project driven methodology and the integration of training periods in the industry as from the first year of the four-year long course.
Characterization of Molecular Weight Degradation of Polyamides by Gel Permeation Chromatography
Polyamides are susceptible to attack by environmental pollutants. The surface layer is degraded and the development of a critical thickness of this layer results in a catastrophic loss of mechanical properties. In this work nylon was exposed to nitrogen oxides and the fracture strength was measured. After a period of no change the fracture strength decreased dramatically. Exposed samples were microtomed and the molecular weight distribution of nylon was determined, as a function of depth from the surface, by Gel Permeation Chromatography (GPC). A critical depth for degradation was established beyond which the specimen exhibited unacceptably low fracture strength.
Investigation of Applicability of Two Biodegradable Polymers for Mechanical Applications
Three types of specimens of a polyester-amide and a poly-hydroxybutyrate have been tensile and tensile-impact tested. These specimens represent different geometric characteristics; one specimen has a cold weld line. The influence of injection molding settings on tensile behavior was in agreement with tensile-impact results. Embrittlement was found for all specimen types and both materials after 20 months of storage. The beneficial effect of annealing on toughness was shown for poly-hydroxybutyrate specimens without weld line.
We're sorry, but your current web site security status does not grant you access to the resource you are attempting to view.