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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KINETIC, THERMODYNAMIC AND STRUCTURAL FACTORS GOVERNING THE DISPERSION OF NANOCLAYS IN POLYMER MELTS
Polymer nanocomposites offer a potential solution to improve, while maintaining, multiple, incompatible properties, such as mechanical and optical performance. In order to demonstrate significant property enhancements, a well-controlled dispersion of a nano-scale filler into a polymer matrix is required. Melt processing represents the most economical and flexible route to producing thermoplastic nanocomposites. This paper describes a set of melt compounding experiments to help establish the kinetic and thermodynamic factors that govern the dispersion of layered silicates in ionomers. The results show that the stress imparted during the melt blending influences dispersion. However, the thermodynamic compatibility between the filler surface, organic modifier and matrix polymer plays a dominant role in the exfoliation process.
DETERMINATION OF KINETIC CURE PARAMETERS CONSIDERING SPECIFIC HEAT TEMPERATURE DEPENDENCE
In this work, an algebraic-differential equations (EAD) system is applied to estimate parameters using both isothermal and non- isothermal data. Temperature dependence of the specific heat is considered inside the EAD as an algebraic restriction. The estimation procedure is based on the use of a mass and energy balance in DSC furnace. The approach found all kinetic parameters by using deterministic and heuristic algorithms. The results show that the use of an energy balance is a good methodology to estimate cure kinetic parameters of both isothermal and non-isothermal experiments.
ANALYSIS OF THE PROPERTIES AS CONTENT OF END-GROUP FOR POLYCARBONATE (PC)IN MELT POLYMERIZATION PROCES
There are two processes to polymerize polycarbonate in the petrochemical industry: One is interfacial polymerization(interfacial PC) and the other is melt polymerization(melt PC). Recently, the latter is mostly used in that it is eco-friendly process. The most difference of product produced by two systems is the content of specific end-group. It is detected to a little bit value in interfacial polymerization, while it generally has more content in melt polymerization. It is supposed that the more content of the end-group is, the bigger change of the property induce as surrounding environment. In order to analyze an effect of the end-group, polycarbonate substituted to other end-group was made from melt PC using a suitable end-capping agent. And then, several properties were examined like melt index, viscosity and color. As the result, the end-capped PC showed less change of the properties than general melt PC, and it is similar to interfacial PC. It was verified that the properties of melt PC is adversely affected by the specific end-group.
DEVELOPMENT OF LIGNIN-BASED THERMOPLASTICS FOR COMPOSITE APPLICATIONS
Current trends in renewable resin systems for composite applications will be presented in this talk. Our recent efforts on synthesis of lignin-based bio-thermoplastics show significant promise. Various methods of establishing chemical synthetic routes for producing lignin-based thermoplastics that can increase the value of lignin by-products will be discussed. Compatibilization of blends of lignin with different polymeric matrices results good thermoplastic for certain lignin loadings. These routes would provide a low-cost alternative, recyclable resins for future composite applications.
POLYESTER DEVELOPMENT PROGRESS FOR EXTRUSION BLOW MOLDING APPLICATIONS
This work highlights three decades of polyester resin development for the extrusion blow molding (EBM) process. The optimal formulation for a clear EBM material must fulfill three main requirements: process efficiently on existing equipment, produce bottles with robust drop impact performance, and have an acceptable recyclability story. Balancing these criteria in a single formulation is challenging, since obtaining compatibility in the PET recycle stream inherently causes drawbacks to processing and bottle performance. Nevertheless, significant innovation has enabled Eastman to provide the market with a comprehensive portfolio of copolyester technology, suitable for a variety of needs.
DIBENZOATE PLASTICIZER PLATFORM DEVELOPMENT FOR PVC APPLICATIONS
Dibenzoates plasticizers are well established and are used in PVC applications. Chemically these plasticizers are non-phthalates and dibenzoates function well as high solvating type plasticizers. In the past, new benzoates, dibenzoate blends and grades were developed to keep pace with formulators’ needs. A new generation dibenzoate triblend platform has been developed to offer formulators an improved high solvator to complement general purpose plasticizer performance. A basic plastisol evaluation protocol was utilized to help determine how to formulate with these new blends. In addition to the basic data developed, examples of performance in starting plastisols will be shown.
EXPERIMENTAL INVESTIGATIONS ON VANE EXTRUDER FOR POLYMER SHORT THERMO-MECHANICAL HISTORY PROCESSING
The screw extruder is one of the mostly used equipment for polymer processing and its conveying mechanism is based on the shear flow. This leads to the materials experiencing a long thermo-mechanical history. Vane extruder is an innovative equipment which totally alters the shear conveying mechanism of screw extruder. The solid compacting and conveying section, the establishment of pressure section and the melting section simultaneously occur in the vane extruder which is different from the screw extruder. This results in the short thermo-mechanical history in the vane extruder. And the crushing of solid-bed and the elongational flow are generated in the vane extruder. Therefore, it does not decrease the plasticating and mixing effects even though it has shorter thermo-mechanical history than the screw extruder. The plasticating and mixing effects are found better in the vane extruder compared to the screw extruder through the experimental investigations.
STUDY OF THE INTERFACIAL PROPERTIES OF FIQUE FIBER REINFORCED POLYETHYLENE ALUMINIUM
By using a pull-out test the mechanical bonding at the interface fique fiber-Low Density Polyethylene- Aluminum (LDPE- Al) matrix was measured. Experimental results of the shear stress at the interface point out that a critical length of 21 mm optimally transfers the stresses from the matrix to the fiber. In addition, a volume of 50% fique fiber showed better mechanical strength when compared to volumes of 10 and 30%. Optimization of the critical length and volume ratio (fique fiber/matrix) allowed the manufacturing of boards using a hot plate machine.
POLYHEDRAL OLIGOMERIC SILSESQUIOXANE SURFACE MODIFICATION AND NANODISPERSION
The dispersion of nanoscale reinforcements in polymer matrices remains a significant challenge in achieving desired properties in nanocomposite materials. Polyhedral oligomeric silsesquioxane (POSS) nanostructured chemicals, consisting of an inorganic cage structure with an organic corona, provide a unique opportunity to control nanoscale dispersion by tuning the organic substituents to allow interaction with specific substrates. The structure can also be tailored to provide preferential surface segregation in a polymer melt to achieve desired modification of surface properties. The estimation of POSS solubility in polymer matrices through calculated solubility parameters and molecular dynamic simulations will be discussed in relation to experimental results. The dispersion of POSS and POSS-modified nanoparticles in selected systems will be reviewed.
PRECISION CONTROL OF MORPHOLOGY,ORIENTATION AND FUNCTION WITH FIELD ASSISTED ALIGNMENT TECHNIQUES ON NOVEL ROLL TO ROLL MANUFACTURING PLATFORMS
There is a significant excitement brewing in the application of polymers for functional films for new applications such as transparent conductive flexible electrodes for flexible electronics, high throughput high selectivity separation membranes and ultrahigh density storage devices. These are enabled by the recent developments in roll to roll manufacturing that combines multiple functions in one machine to add desired properties. For example, at National Polymer Innovation Center at University of Akron, we developed a hybrid roll to roll manufacturing line that facilitate incorporation of continuous conductive nanofibers into polymer solutions/or photocurable monomers to produce flexible transparent conductive electrodes to enable flexible displays, photovoltaics and OLEDs. This was possible by integrating a large farm of nanofiber generators to single and multilayer casting system to produce pilot scale films that can be flexed many hundreds of time around sharp radius without loss of initial conductivities and transparencies. We will illustrate the utility of this R2R line in producing die sensitized flexible PV devices. In traditional polymer processes involving flow, the anisotropic phases inevitably oriented with details of the flow field and rarely if at all these phases/nanoparticles are oriented normal to the surfaces of the products in particular films. In order to achieve this “Z-orientation” or phases/and or particles normal to the film plane, we also developed a brand new 70ft long machine to orient and organize polymer phases, nanoparticles normal to the film plane. This is achieved by application one or more of following external force fields: electric, Magnetic and thermal gradient fields. These are incorporated in this pilot scale line. In this presentation, we will show illustrations of the use of this line in anisotropic nanoparticle alignment, block copolymer phase alignment in the Z-direction.
EFFECT OF TYPICAL MELT TEMPERATURE NON-UNIFORMITY ON FLOW DISTRIBUTION IN FLAT DIES
In this study, the influence of non-uniform incoming melt temperature profiles on the flow in a flat die is evaluated. Flat film die flow channels are typically designed to provide uniform flow distribution at the die exit assuming uniform incoming melt temperature profiles. However, in real extrusion conditions, it can be challenging to obtain an ideally uniform melt temperature delivery to the die. There are many reasons why the melt temperature non- uniformity is obtained. Two typical scenarios are evaluated; (i) the temperature profiles generated by an incorrect melt pipe design will be calculated and input in a die flow model as inlet boundary condition and (ii) the influence of a polymer subject to excessive viscous dissipation in the extruder. This work uses 3D computational fluid dynamics (CFD) models.
A SINGLE MACHINE SCHEDULING STRATEGY FOR ENERGY SAVING IN INJECTION MOLDING PROCESS
A single machine scheduling strategy is proposed for minimizing the global energy consumption of an injection molding machine with multiple products. The total energy consumption contains three parts: switchover energy, transitional energy and stable operation energy. The transitional energy consumption model is developed. The scheduling problem is formulated as a typical travelling salesman (TSP) problem, which will be solved by a GA-based lexicographic optimization framework. Experimental results show the feasibility and effectiveness of the proposed energy-saving-oriented single machine scheduling strategy.
EFFECT OF EPOXIDIZED SOYBEAN OIL ON MECHANICAL PROPERTIES OF POLYLACTIC ACID BLENDS
Epoxidized soybean oil (ESO), as a plasticizer, was melt blended with polylactic acid (PLA) in an internal mixer. The effects of ESO on the mechanical properties of the PLA/ESO blends were studied by means of the tensile, flexural, and impact tests. The elongation at break for the PLA/ESO blends was obviously improved with an increase in ESO loading, and was 16.8 times than that for pure PLA when the ESO loading was 5 wt %. Compared with pure PLA, the blends appeared lower tensile strength, tensile modulus, flexural strength, and flexural modulus. However, ESO improved impact strength for PLA matrix. Impact strength for the blends increased at first and then decreased as the ESO loading increased, which arrived a maximum of 2.9 times than that for pure PLA when the ESO loading was 10 wt %.
REAL-TIME TRACKING OF BIREFRINGENCE, WEIGHT AND THICKNESS DURING DRYING/CURING OF SOLUTION CAST POLYMER COATINGS AND FILMS
This paper describes the design and performance of a new instrument to follow the drying behavior of polymer solutions and monomers during drying/photocuring. This real-time multisensory instrument follows the in-plane and out-of-plane birefringence, weight, thickness and surface temperature during the course of drying of coatings and films in a controlled atmosphere. It is specifically designed to simulate the behavior of polymer solutions inside an industrial size, continuous roll-to-roll solution casting line and other coating operations that are typically used in manufacturing of functional films including flexible electronics and membranes. Processing variables including air speed and temperature, initial cast thickness, solvent type and solute concentration are controlled to study the effect of each parameter on the real-time drying behavior of polymer solutions and their final properties. The instrument can also be modified to investigate the UV curing of non-solvent systems. Several polymer solution systems were tested and the data will be presented during the presentation
DESIGN AND DEVELOPMENT OF THERMOPLASTIC HAND HOLDS FOR PASSENGER SAFETY IN MASS TRANSPORT SYSTEM
Hand holds are the safety devices used in mass transport vehicles to provide support for the standing passengers to hold. The conventional handles are manufactured by metal fabrication process involving lot of secodary operations. The metal handles generally have problems such as poor product consistency, lower productivity, higher cost and weight etc. Engineering thermoplastics is the right choice of material for this application as it offer design flexibility and better aesthetics but the challenge is to ensure long term performance requirements. Designed Innovative thermoplastic handle with finger grip impressions for better comfort. Manufactured using Gas assisted injection molding technology to maintain product consistency, improved productivity, reduced weight and cost. Extensive part testing and validations were done to ensure performance before commercialization. The objective of this paper is to cover in detail the application development process starting from concept to reality meeting all the technical requirements. This successful application development opened up new market space for SABIC Innovative Plastics business and there is huge translation opertunities in Global Mass Transportation market space.
VISCOELASTIC PROPERTIES OF CNT-PC COMPOUNDS: EFFECT OF COMPOUNDING METHOD, CNT-TYPE AND TESTING PROTOCOL
Frequency-dependent viscoelastic properties are used to elucidate the relationships among the method of compounding, the types of CNT used within the CNT-PC composite and the changes in structure (CNT-PC interaction) and molecular weight of the base PC. CNT-PC interaction increases increasing CNT content and CNT aspect ratio. Addition of the CNT to a TSE at entry ports after attainment of a PC melt provides higher CNT-PC interaction. Increasing TSE residence time by using multiple passes, significantly decreases the molecular weight of the PC within the CNT-PC composite that is attributed to chain-scission that is intensified by the presence of the CNT-PC interaction.
DETERMINATION OF ENVIRONMENTAL STRESS CRACKING FAILURE MODE IN INVESTIGATIONS OF CPVC FIRE-SUPPRESSION SPRINKLER PIPE FAILURES
This paper discusses three separate failure analysis case studies involving Chlorinated Polyvinylchloride (CPVC) fire suppression sprinkler pipe(s) alleged to have failed due to Environmental Stress Cracking (ESC) from exposure to an incompatible chemical. The investigations highlight the importance of the interpretation of fracture surface morphology, review of background information regarding service history, performing material characterization testing, as well as developing an understanding of the interaction of various chemicals with CPVC material when attributing a failure of CPVC sprinkler pipe to ESC. The case studies discussed are helpful in understanding the ESC mechanism in CPVC sprinkler pipes, which is a complex failure mode. This paper discusses the technical issues that should be addressed in determining whether ESC is the primary cause of failure in a CPVC fire suppression sprinkler pipe system.
TRANSCRYSTALLIZATION OF IN-SITU MICROFIBRILLAR PP/SAN BLEND PARTS MOLDED VIA WATER-ASSISTED INJECTION MOLDING
In this work, the crystal morphology of water-assisted injection molded (WAIM) parts of in-situ microfibrillar polypropylene/acrylonitrile–styrene copolymer (PP/SAN) blends with four weight ratios were studied. The results showed that transcrystalline structures formed in the inner layers of the WAIM PP/SAN blend parts at the SAN contents of 4, 6, and 8 wt%, but were absent at an SAN content of 2 wt%. The formation mechanism of the transcrystalline structures was interpreted with the aid of stress and temperature ?elds of the melt within the mold cavity under high-pressure water penetration during the WAIM. It was found that the high shear stress and cooling rate in the inner layer were responsible for the formation of the transcrystalline structures.
EFFECT OF POLYMER VISCOSITY ON POST-DIE EXTRUDATE SHAPE CHANGE IN COEXTRUDED PROFILES
Bi-layer flow in a profile coextrusion die was simulated. Prediction of post-die changes in extrudate profile was included in the simulation. Mesh partitioning technique was used to allow the coextrusion simulation without modifying the finite element mesh in the profile die. Effect of polymer viscosities on the change in profile shape after the polymers leave the die is analyzed. It is found that a difference in the viscosities of the coextruded polymers can lead to a highly non-uniform velocity distribution at die exit. Accordingly, post-die changes in extrudate shape were found to be widely different when the polymers in the two coextruded layers were changed.
INVESTIGATION OF HIGH POWER ULTRASONICS FOR DEPOLYMERIZATION OF POLYLACTIC ACID
This research work explores the feasibility of ultrasonics to recycle lactic acid by depolymerizing. Post consumer PLA chopped up to 1mm2 was exposed to high power ultrasonics with water or methanol as the suspension media. The treatments were carried out in the presence of organic and ionic salts of alkali metals such a potassium carbonate and zinc chloride as the catalysts. The treatments were replicated by replacing ultrasonics with Hot water bath as the energy source. Analysis with HPLC indicated PLA to Lactic acid conversion was achieved with yields up to 90% utilizing ultrasonics. Energy calculations indicated that Ultrasonics used 30% less energy to achieve the same yield levels as achieve with hot bath technique
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