SPE Library

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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Recycling

Various topics related to sustainability in plastics, including bio-related, environmental issues, green, recycling, renewal, re-use and sustainability.

SUBSTITUTION OF POLYLACTICACID (PLA) IN PLACE OF POLYVINYLCHLORIDE (PVC) IN TRANSPARENT SIGNAGE FOR RETAIL USE

Daniel Brittingham , Nicole Larson, May 2010

This project aims to investigate the material properties of Polylactic acid (PLA) and to compare them with Polyvinyl chloride (PVC) which is currently used in retail signage. There problems inherent in changing a process from an established material to a biodegradable polymer. The mechanical properties of PLA are under scrutiny to determine if it can be a reasonable substitute for PVC a non biodegradable plastic that must be land-filled or recycled at considerable cost after its post-consumer use. Many environmentalists suggest that biodegradable plastics can be substituted to fill the same roles as conventional polymers. PLA is a biodegradable polymer that is available in grades that are transparent and are manufacturable in most common thermoplastic processing methods including extrusion. PLAƒ??s substitution for PVC in this application can help to eliminate landfill and reduce overall pollution.

SYNTHESIS AND PHYSICAL CHARACTERIZATION OF BIODEGRADABLE PLA/PHBV FOAMS

Esther Richards , Reza Rizvi , Andrew Chow , Hani Naguib, May 2010

This paper examines the effect that blending two biodegradable polymers has on the thermal properties and morphology of the resultant foams blown with carbon dioxide (CO2). Polylactic acid (PLA) Polyhydroxybutyrate-co-valerate (PHBV) and blends of both were foamed and characterized in terms of thermal characteristics relative density cell size and foam morphology. The results indicate that although PLA and PHBV are immiscible the presence of small quantities of PHBV could lead to low density foams with finer more uniform cells.

THERMAL AND RHEOLOGICAL PROPERTIES OF PHB SYNTHESIZED WITH VARIOUS HYDROXYVALERATE CONTENT FOR POTENTIAL USE IN FOOD PACKAGING

Sunny Modi , Kurt koelling , Yael Vodovotz, May 2010

PHB (Poly (3-hydroxybutyrate) families of naturally occurring polymers are extracted from micro-organisms.PHB behaves similarly to conventional thermoplastics, yet are fully biodegradable in common composting conditions.To improve flexibility for potential food packaging applications, PHB can be synthesized with various copolymers such as 3-hydroxyvalerate (HV). The objective of this study was to characterize the thermal and rheological properties of PHB synthesized with various valerate contents and relate these findings to potential food packaging applications.

THERMAL STABILIZATION OF BIODEGRADABLE POLY-HYDROXYBUTYRATE (PHB) IN MELT EXTRUSION PART 1: POLY-OLIGOMERIC-SILSESQUIOXANE

Y. Shaked , H. Dodiuk , S. Kenig , C. Schwier , S. McCarthy, May 2010

Poly-Oligomeric-Silsesquioxane POSS nano modifier was examined as a thermal stabilizer for PHB.Melt compounding of Poly-Hydroxy-Butyrate PHB copolymers with different POSS moieties was performed.Reactive and non-reactive POSS nano modifiers were used. The effect of modification on PHB thermal stability was evaluated by changes in rheology and molecular weight. POSS modifiers with unique core-shell structures were found to significantly reduce the loss in molecular weight during melt mixing possibly by decreasing viscous-heating effects.

UNSATURATED POLYESTER RESIN FROM CHEMICAL RECYCLING OF OFF-GRADE POLYETYHYLENE TEREPHTHALATE

Ali R. Zahedi, May 2010

Poly(ethylene terephthalate) [PET] from off-gradesof industrial manufacturer was depolymerised usingexcess ethylene glycol [EG] in the presence of metalacetate. Influences of the reaction time volume of EG and catalysts concentrations on the yield of theglycolysis products were investigated. In this study wehad three 3-level factors for reaction time volume ofEG and catalysts concentrations on the basis ofTaguchi's statistical method. The optimal conditionsare reaction time of 3 h molar ratio (EG to PET) of 5 weight ratio (catalyst to PET) of 0.25 wt%. Theglycolysis products were analysed for hydroxyl valueand identified by DSC and VPO. The optimum samplewas used to produce unsaturated polyester resin [UPR]by maleic anhydride [MA]. The samples alsocharacterized well by FT-IR 1HNMR and 13CNMR.

WEATHERING PERFORMANCE OF A SCRATCH RESISTANT WEATHERING PERFORMANCE OF A SCRATCH RESISTANT

T. M. Lewis, A. I. Isayev, J. Keum, May 2010

The weathering performance of a Lexan* copolycarbonate resin was studied against a benchmark PC resin. Known ISO, ASTM and SAE weathering protocols were used and observed differences explained. Lexan* copolycarbonate resin offers a scratch resistant polycarbonate solution that opens up new possibilities in terms of part performance. Key applications range from mobile phones to interior automotive trims and benefit from the elimination of secondary operations due to the increased hardness of the material. This can lead to costout opportunities and environmentally friendlier solutions where conventional protective hard coatings or painted surfaces are considered.

WELDABILITY OF BIOPLASTICS

S.B. Tan, P.R. Hornsby, M. McAfee, M.P. Kearns, M. McCourt, P.R. Hanna, May 2010

The cooling process in conventional rotational moulding has a relatively long cycle time. It is normally accomplished by external forced air convection and external water spray cooling. In some instances, an evaporative cooler is employed to create atomised fog external to the mould during the cooling cycle. Internal water spray cooling is an attractive approach to reduce the cycle time and enhance the product properties in rotational moulding. It is shown that water spray cooling of polymers is affected by water droplet size and water droplet velocity. This paper outlines an introduction to the characterisation of water droplets. The effects of these parameters on water spray cooling of polymers are also presented, using a purpose built experimental test rig. With the growing demand for environmentally friendly biorenewable resources, there has been a parallel growth in the development of bioplastics. These include commercially available starch-derived plastics and plastics derived from renewable oil and proteins. As with any plastic, these new materials must often be joined to produce final products. This paper reviews impulse and ultrasonic welding of PLA as well as friction welding of plant protein-based plastics. It was found that each of these plastics can be welded with weld strengths matching the parent material strengths.

Using low-cost waste for polyhydroxybutyrate bioplastics

Marysilvia Ferreira da Costa, Carolina Carvalho de Mello, Jeremias de Souza Macedo, Rossana M. S. M. Thire, April 2010

Biopolymer-based composites reinforced with a byproduct of coconut-fiber processing were made successfully using compression molding.

Microcellular processing of biobased, biodegradable polymer blends

Shaoqin Gong, Srikanth Pilla, Lih-Sheng Turng, Jungjoo Lee, Alireza Javadi, Adam J. Kramschuster, April 2010

Using microcellular injection molding to prepare renewable polymer composites could lead to components with lower cost, improved material properties, and an extended range of applications.

Optical Sorting in High-Definition – New Exciting Applications for Plastics Separation

Felix A. Hottenstein, March 2010

This paper presents the latest MSS optical sorting technology that can be used for an exciting array of new application due to new high-resolution NIR, color and metal sensors. From post-consumer to durable engineering plastics and electronic scrap this new high-resolution technology will advance the separation of even highly complex mixtures to the next level. A series of different applications will be discussed in detail.

Enabling Recycled TPO for Automotive Applications Using Scratch and Mar Additives

Nikolas Kaprinidis, Hung Pham and Johanne Wilson, March 2010

Very often plastics manufacturers utilize scratch and mar additives to reduce the occurrence of surface defects. This paper shows that a scratch additive SM1 can be used in a talc filled 100% recycled TPO in order to enable it to meet these stringent scratch standards and therefore be implemented into automotive applications.

Opportunities for Bio-polymer Resource Conservation through Closed Loop Recycling

J.A. Colwill, E.I. Wright, A.J. Clegg, S. Rahimifard1, N.L.Thomas, B. Haworth, March 2010

Oil-derived plastics have become well established as a packaging material over the past 75 years due to their many technical and commercial advantages. However, the disposal of plastic packaging waste, a large proportion of which still goes to landfill, continues to raise increasing environmental concerns. Meanwhile, the price of oil continues to rise as demand outstrips supply. In response, biodegradable polymers made from renewable resources have risen to greater prominence, with a variety of materials currently being developed from plant starch, cellulose, sugars and proteins. Whilst the polymer science continues apace, the real ecological impacts and benefits of these materials remain uncertain. Although life cycle assessment (LCA) has been used to provide comparisons with oil-derived plastics, published studies are often limited in scope, allowing the validity of their conclusions to be challenged. The literature appears to support the popular assumption that the end-of-life management of these materials requires little consideration, since their biodegradable properties provide inherent ecological benefits. Opportunities for conserving resources through the recycling of biopolymers are rarely addressed. Through a review of current academic, industrial and commercial progress in the field of biopolymers, a number of LCA case studies are proposed which will address this weakness in existing research, related to the recycling of biopolymers. These, or similar, studies are required to provide a more complete picture of the potential effects of a transition from non-renewable to renewable polymers, thus allowing material selection decisions to be made with greater confidence throughout the packaging supply chain.

FOAMING OF PLA – THE USE OF MELT STRENGTH ENHANCERS TO ACHIEVE LOWER DENSITY FOAMS PRODUCED BY CHEMICAL BLOWING AGENTS

Elizabeth GRIMES, March 2010

Many factors influence the ability to produce a good quality, low density foam. Physical factors include proper cell nucleation; melt strength, viscosity, molecular weight and solubility of the gases generated by the chemical blowing agent in the polymer to name a few. There are also outside limiting factors that include regulations around some physical blowing agents’ global warming potential, which can lead to expensive equipment retrofits. Foaming PLA is particularly challenging due to its poor melt strength. The addition of low percentages of an acrylic melt strength enhancer increases the extensional viscosity of the PLA allowing the gases generated by the chemical blowing agents to form a more uniform foam structure. Chemical blowing agents were chosen as an option to reduce global warming potential without the need for changes to the existing equipment. This paper focuses on the optimum levels of melt strength enhancers in conjunction with various chemical blowing agents to achieve a low density foam with fine cell structure.

Polymer Blends and Composites Derived From Biopolymers

Sharma Suraj, March 2010

Fabrication and evaluation of biodegradable materials from natural resources have attracted significant attention because of sustainability and dwindling petroleum reserves. This research focused on fabricating biodegradable composites from natural polymers such as proteins and describing the properties of plastics made from these biopolymers. Specifically, plastic samples from partially denatured, animal co-product proteins, such as feathermeal and bloodmeal, were successfully produced through the compression molding process. The molded bioplastics demonstrated modulus (stiffness) comparable to commercial synthetic plastics such as polystyrene, but lacked toughness, which is common among plastics produced from natural feedstock and/or their byproducts. Therefore, this research used blends of undenatured and partially denatured proteins to improve toughness. Plastic molding conditions for undenatured animal proteins, such as chicken egg white albumin and whey, and animal co-product proteins, such as feathermeal and bloodmeal were experimentally identified in order to prepare their blends. Plastic samples from these biomacromolecular blends demonstrated improved mechanical properties. Properties such as modulus, tensile strength, and elongation were also predicted using theoretical models known for polymer blends and composites.

Comparison of Carbon Footprint of Standard Thermoplastic Urethane (TPU) and TPU from Renewable Resources

Kenneth Hughes, March 2010

Merquinsa has developed Pearlthane® ECO, based upon polyols derived from various plant sources. The driving force to develop this bio TPU was our interest in creating a more sustainable product offering for companies and brands to choose from. These products, with very similar thermal, mechanical and rheological behaviour to standard TPU’s, have been widely accepted in the marketplace and are affording design engineers performance with sustainability. Although conceptually it is believed that producing TPU parts from bio based products is more environmentally friendly, Merquinsa will quantify and compare the greenhouse gas (GHG) emissions to validate this belief with hard science. The quantification of greenhouse gas (GHG) emissions associated with the production of a product is commonly referred to as the “carbon footprint”. PAS 2050 is a method prepared by the BSI British Standards for assessing the product life cycle GHG. For the purpose of this comparison, the lifecycle is defined as beginning with raw material manufacture, either from agricultural or petrochemical inputs, through to the delivery at our customer’s facility. This is commonly referred to as the cradle-to-gate approach. Any process at customers beyond this point will be similar for the Pearlthane® ECO and standard Pearlthane® TPU materials.

Sustainability & Regulatory Requirements

Naeem Mady, March 2010

What is Sustainability Industry Sustainability is related to the quality of life in a community, where the economic, social and environmental systems that make up the community provide a healthy, productive, and meaningful life for all community residents, present and future. EPA “Create and maintain conditions under which [humans] and nature can exist in productive harmony, and fulfill social, economic and other requirements of present and future generations of Americans." The most widely quoted definition internationally is the "Brundtland definition" “Meeting the needs of the present without compromising the ability of future generations to meet their own needs." Common Approach to Packaging Sustainability • Materials substitution • Recyclable, reusable, biodegradable • Broader view of packaging sustainability • Cost reduction opportunity • Greater impact in supply chain Industry Commitments- The Sustainable Packaging Coalition Committed to as an inspirational vision for packaging where: • Material is sourced responsibly • It is effective and safe through its lifecycle • Packaging meets market criteria for performance and cost • It is made entirely using renewable energy • Once used, it is recycled efficiently To provide a valuable resource for subsequent generations

Comparison of Life Cycle Greenhouse Gas and Energy profiles of bio-plastics and petroleum based plastics

David Grewell, Ph.D., Robert Anex, Ph.D., Julius Vogel, March 2010

While the first man-made plastics were derived from biomass resources, they were progressively replaced as of the 1930‟s by petrochemical polymers. Plastic production and consumption reached approximately 245 million metric tons in 2008 worldwide and is expected to increase with economic growth in developing and emerging countries. With an estimated per capita plastic consumption of up to 140 kg annually in 2015, Europe and North America will remain the top positions, while packaging is the largest end use of thermoplastic resins (32%), followed by building and construction applications (14%), consumer and institutional products (13%) and other application that include medical and recreational products (14%) in the U.S. [1, 2]. However, these conventional plastics have the disadvantage that they are produced from diminishing fossil petroleum resources such as gas and petroleum and once they are produced and manufactured into consumable products they are very resistant to degradation processes which leads to litter problems, injury to wildlife and disposal may cause environmental damage due to emissions from combustion. Due to these concerns, there has been increasing interest in bio-based plastics. In principle, biodegradable polymers and plastics can also be manufactured from petrochemical raw materials. However, bio-based plastics, are defined here as plastics that are fully or partially produced from renewable feedstock. Biodegradable bio-based plastics in particular have the potential to replace traditional plastics in applications ranging from packaging, to disposable road signs, to drug delivery, while they do not significantly impact the environment. However, because plastic waste significantly contributes to pollution and consumes landfill space, removal and disposal is an important step in the lifecycle of plastic products. The disposal costs of plastic material include the costs to remove the final product from the consumer and the costs of waste abatement. This paper will present all commonly used end product treatment options of plastic waste and introduce a method to calculate their beneficial as well as non beneficial effects in terms of energy consumption, emissions generation and financial costs.

Packaging as a Waste Reducer

Rachael Hopkins, March 2010

Too often, we think of packaging as waste and as something that we need to eliminate altogether. In a global society, where we are becoming more efficient with our food and goods production, we need to broaden our view of packaging and understand how it, if carefully designed, can reduce waste. There are more and more choices on the type of packaging for consumer products including bio-based plastic packaging, recycled content packaging and compostable materials. How do we then decide what type of packaging to use for our products and how do we make the best choice for our brands? This discussion will introduce the idea that packaging can be a waste reducer and present the idea that, in order to truly reduce waste, we must have a more rigorous understanding of the function of packaging. It will also delve into alternative end-of-life options that are complimentary to recycling.

Landfill Biodegradation of Conventional Synthetic Polymer Using BIOchem Organometallic Additives

J. Schleicher, Jr., March 2010

A variety of anaerobic landfill microbes are shown to be able to metabolize conventional synthetic polymer compositions such as PVC plastisol signage film, EVA sheets, and expanded polystyrene and polyvinyl chloride foam containing BIOchem organotitanate or organozirconate additives that provide hydrophilic points of attack, but do not catalyze degradation during service in an aerobic environment. What is claimed is that ordinary commodity plastics such as PVC, PS, PP and EVA can be rendered landfill biodegradable with as little as 1 phr of the subject additive under anaerobic landfill conditions while performing equal or better than controls under normal use having aerobic conditions such as oxygen and light. The technology will be shown to make it possible to render synthetic polymers sustainable while having inherently more robust properties than biobased polymers. Application considerations will be presented as to recommended dosages, various additive forms, optimal extrusion conditions, and possible interference mechanisms with other additives such as zinc based stabilizers that interfere with the efficiency of the anaerobic microbe’s ability to eat the plastic.

Recycling Post Consumer Plastic Automotive Fascia

Ananda Ponnusamy, Barry Watson, Dean Eberhardt and Jayme Dood, March 2010

In this World we are facing many environmental issues and one of the most visible is plastic solid waste pollution going into our landfills. Contained in this plastic solid waste feed-stream are automobile fascias that are not repairable or useable by the primary or secondary markets. These unusable fascias are presently being collected by MRC Polymers. The Fascias are processed to reclaim the thermoplastic raw material. The thermoplastic is then compounded into pellets to meet the customer’s requirement for various applications. The process includes sorting where the material is segregated into different types of plastics. Then the sorted parts are reduced in size through a shredding and grinding process. Following the size reduction, the material is passed through a non-chemical washing process to remove paint from the fascia regrind. Then the washed regrind is transferred to be compounded into various products. In the compounding process, the properties of the product are improved by utilizing additives when necessary. The final compounded plastic resin enables molders to produce first quality products. This recycled product replaces virgin thermoplastic resin providing a cost savings, reducing the use of energy, and lowering the landfill waste. MRC will present an overview of this process of Sorting, Grinding, Washing and Compounding and its application in automotive industry. MRC will also show the property improvement throughout the process that meets the customer requirement for a specific application.