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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Milton O. Vázquez , César Gómez , Sergio Gómez-Salazar , R. González-Núñez, May 2010
Composites of post-consumer high density polyethylene (HDPE) with agave fibre were prepared by extrusion and coated with chitosan. A chemical pretreatment was applied to the composite to enhance chitosan gel compatibility. The adsorption capacity of the composite coated with chitosan was evaluated for Cd(II) and Cu(II). The coated composites were characterized by SEM, ATR-IR and XPS. Atomic Absorption Spectroscopy (AA) was used to measure metal uptake in batch studies. Adsorption Isotherms were obtained at three different pH values. The results of this study demonstrate the composite's ability to immobilize chitosan on its surface and its capacity to adsorb metal ions.
Daniel E. Ramírez-Arreola, Guillermo Sandoval-Hernández, Martín Arellano, Cesar Gomez, Rubén González-Núñez, Denis Rodrigue, May 2010
Demoulding components without damage to either the components or tool is critical to successful replication processes. Accurate demoulding force prediction prior to tool fabrication helps designers optimize replication tools to minimize the demoulding force and resultant stress on replicated parts. Various models have been proposed to predict demoulding forces. One such model, the stair-step model, was developed by Colton et al for stereolithographic moulding tools. This paper investigates applying the model to other periodic surfaces with validation using published experimental data. In addition validity of the model for application to micro mould surfaces produced by micro milling is discussed.
Daniel E. Ramírez-Arreola , Guillermo Sandoval-Hernández , Martín Arellano , Cesar Gomez , Rubén González-Núñez , Denis Rodrigue, May 2010
Injected molded nanocomposite blends based on PCL/TPS and Cloisite 15A (C15A) were prepared and its mechanical properties were studied. The injected samples were exposed to the environment in order to analyze the influence of exposure time and moisture uptake over mechanical properties. The results showed that samples tested right after molding exhibit low mechanical resistance to impact and high Young modulus, while increasing the environmental exposure time reduced the Young modulus and substantially increased the medium failure energy. On the other hand, using C15A increases the medium failure energy, and an important interaction between TPS, moisture and clay was observed.
Lubomír Benícek, Lenka Chvátalová, Roman Cermák, Vincent Verney, May 2010
Three different polyethylene pipe grades and three different lots of one PE pipe material were investigated with fracture mechanics procedures under cyclic and impact loads. The cyclic tests with Cracked Round Bars allowed a ranking of the different PE pipe grades and lots concerning crack resistance as a function of failure time as well as of crack initiation time. The ranking corresponded to the expectations based on the molecular and morphological properties of the materials. Concerning lot-to-lot variations, in particular, a correlation to crystallization kinetics, melt flow rate and density measurements could be established.
Lubomír Benícek , Lenka Chvátalová , Roman Cermák , Vincent Verney, May 2010
The work directs attention towards the influence of annealing temperature on transformation of polymorphic composition and mechanical properties of isotactic polybutene-1 (PB-1). For these purposes three different commercial-available grades of PB-1 were chosen.Specimens prepared by injection molding were annealed at given temperature (-22 +6 +22 +40 and +60 ?øC) in the interval from 0 to 48 days. The changes in structure and properties were followed by tensile testing. A nonmonotonic evolution of tensile properties was observed.
Incorporation of multi wall carbon nanotube (CNT) into the thermotropic liquid crystal polymer matrix (TLCP) obtained high performance polymer nanocomposites. For fabrication of high performance polymer nanocomposites, major challenge is to improve the dispersion of CNT in the TLCP matrix and the interfacial adhesion between CNT and the TLCP matrix. In this study, Multi-wall carbon nanotube (MWCNT) reinforced TLCP nanocomposites were prepared by a melt compounding using twin-screw extruder. The CNT was functionalized with chemical surface modification to introduce carboxyl groups onto the surfaces of CNT for uniform dispersion and induce excellent interfacial adhesion. The rheological, mechanical, morphological, and thermal properties of TLCP/CNT nanocomposites were investigated.
It is known industry wide that polypropylene (PP)
resins plasticate at reduced rates compared to other
olefins. While many causes have been suggested for this
problem a solution was not. A simple spiral fluted
extensional mixer (SFEM) was first introduced for the
single screw extruder (SSE) for its superior compounding.
[1 2 3 4 5]. A variation the Elongator II hereafter SFEM
II was tested against a control screw for output. A 100%
increase in output was found over a conventional screw—
more than making up for PP’s historically low rate.
Because the SFEM series is noted for its ability to
compound like a twin we investigated mixing on the SFEM
II. The investigation compares the flow to a simple
computer model. A color concentrate of just 0.5% was
used with frozen pullouts or carcasses showing the mixing
during operation. The extrudate is examined and even
when magnified to 100X does not show striation lines.
It is known, industry wide, that polypropylene (PP) resins plasticate at reduced rates compared to other olefins. While many causes have been suggested for this problem, a solution was not. A simple, spiral fluted extensional mixer (SFEM) was first introduced for the single screw extruder (SSE) for its superior compounding. A variation, the Elongator II, hereafter SFEM II, was tested against a control screw for output. A 100% increase in output was found over a conventional screwƒ?? more than making up for PPƒ??s historically low rate.Because the SFEM series is noted for its ability to compound like a twin, we investigated mixing on the SFEM II. The investigation compares the flow to a simple computer model. A color concentrate of just 0.5% was used with frozen pullouts or carcasses showing the mixing during operation. The extrudate is examined and, even when magnified to 100X, does not show striation lines.
This paper attempts to show through case studies how plastic product failures could be prevented. Failures of plastic products manufactured from HDPE, PBT, and glass-filled nylon material are discussed. In each case study, the root-cause of the plastic product failure has been identified through a failure analysis investigation. The corrective action during the material selection process, the part design process, or the manufacturing process that would have prevented the failure has been suggested. The discussion of these case studies will enhance the understanding of the common errors occurring during the plastic product cycle. This paper should foster further discussion and reporting with focus on prevention of plastic product failures.
Rajendra K. Krishnaswamy, Supicha Kridaratikorn, Yelena Kann, Renuka Bhoyar, Stephen McCarthy, Douglass S. Kalika, Patrick Smith, May 2010
The mechanical properties of bio-based, biodegradable poly (hydroxy butanoic acid) or PHB copolymers are known to change considerably over a period of time after their parts are fabricated. This study will focus on the changes in semi-crystalline morphology during this aging process. The semi-crystalline morphology is characterized using the three-phase model (crystalline, mobile amorphous and rigid amorphous phases) and through a variety of experimental probes including thermal analysis, refractometry, x-ray diffraction and solid-state NMR.
S. Ramaswami , D. A. Zumbrunnen , G. M. Harrison, May 2010
An in situ structuring rheometer (ISSR) has been developed that allows simultaneous controlled formation of structure in polymer blends and composites and measurements of rheological properties. Multi-layer, interpenetrating, and platelet polymer blend morphologies are examples of structure types producible. Networks among solid particles and dispersions can also be formed.The ISSR is modular for installation into existing rheometer platforms. In situ structuring in the melt occurs by chaotic advection which recursively stretches and folds melt domains. Characteristic structure sizes in the melt can reduce to nano-scales so the ISSR also has application to nanocomposites.
A new range of polycarbonate copolymers derived from bisphenol-A (BPA) and specific bio-sourced monomer derived from castor bean oil is presented. These copolymers, designated LEXAN* HFD resins, offer an improved melt flow and ductility balance compared to standard polycarbonate yet offer similar high optical clarity and light transmission properties. Lower temperature processing capability, longer injection molding flow lengths, improved low temperature ductility, and superior mold release performance are all advantages for these new copolymers versus a standard polycarbonate material. Glass fiber-filled formulations of the HFD copolymer show comparable mechanical and impact properties compared to glass-filled polycarbonate materials but show nearly 50% higher surface gloss in injection molded plaques.
A. R. Kamdar , P.S. Dias , Y.J. Lin , B.C. Poon , P. Ansems , A. Hiltner , E. Baer1, May 2010
The effectiveness of elastomeric copolymers as adhesives for polypropylene and polyethylene was studied using coextruded microlayered tapes. The olefinic and styrenic block copolymers were the most effective adhesives of all the elastomeric copolymers used in this study and they delaminated adhesively from the polypropylene-tie-layer interface during T-peel experiments. The effect of tie-layer thickness peel temperature and peel rate on the adhesive properties were probed. Relationships between tie-layer deformation damage zone structure interfacial morphology and delamination toughness were established and a structural mechanism is provided.
Kevin P Menard , Andrew Salamon , Enrique Lazano Diz , Richard Spragg, May 2010
DSC is widely used to investigate phase changes of materials as their temperature is changed, or isothermally.However the information obtained is essentially quantitative as this is a univariate technique that simply measures heat flows. Vibrational spectroscopy can provide complementary information, giving insight at molecular level.into the changes accompanying thermal events or reactions. In addition the multivariate nature of Raman spectra means that it is possible to monitor simultaneous events with different spectral signatures that cannot be distinguished by DSC. A hyphenated system is described, evaluated and applied to some polymer systems
Liang Fang , Ming Wei , Yingrui Shang , Jun S.Lee , Carol Barry , David Kazmer , Joey Mead, May 2010
The surface phase morphology of thermoplastic elastomers can be affected by injection molding parameters. In this paper the influence of mold temperature on the phase morphology of SEBS triblock copolymer was studied through tapping mode atomic force microscope (AFM) and 2D-Fast Fourier Transformation (2D-FFT) analysis. It was found that more orientation was present in the materials prepared using high mold temperatures.The orientation direction of the morphologies could be predicted by computer simulation.2D-FFT analysis can be used to study the domain orientation and structure.
This study presents a new approach which involves
melt-blending a low molecular weight additive and a
polymer at a process temperature where the additive
reduces the process viscosity. Upon cooling, the additive
forms crystalline reinforcing domains. Emphasis is given
to reinforce isotactic-polypropylene (iPP) with calcium
stearate (CaSt). The changes in yield strength and
modulus suggest a synergy between the CaSt and iPP.
Addition of 10% CaSt increases the fracture energy by 5
fold without a loss in modulus and with an apparent
reduction in shear viscosity. CaSt is the only additive
commencing simultaneous improvements.
Ken Miyata , Taku Ozama , Keiji Katsuno , Akihiro Nishioka , Tomonori Koda , Go Murasawa, May 2010
Effect of molecular structure on heat seal properties
for high density polyethylene (HDPE) film was
investigated in this study. Polyolefin is usually adopted as
a sealant material for general packaging system. Melting
temperature of the HDPE film used in this study was 126
oC. The heat seal temperature was controlled and varied at
around melting temperature of HDPE precisely. The
mechanical property of the sealed films was measured by
a T-shape peeling test. Development molecular structure
at film interface for sealing was evaluated in a wide angle
x-ray diffraction pattern and changing of molecular
orientation relaxation corresponding with the mechanical
peeling property. Thermal property was also analyzed by
a differential scanning calorimetry (DSC). The weight
fraction of melting region in heat seal process was
estimated from the DSC thermograms. We discussed that
the amount of melting region is related to the major factor
to decide peeling properties of heat sealed HDPE film.
Ken Miyata , Taku Ozama , Keiji Katsuno , Akihiro Nishioka , Tomonori Koda , Go Murasawa, May 2010
Effect of molecular structure on heat seal properties for high density polyethylene (HDPE) film was investigated in this study. Polyolefin is usually adopted as a sealant material for general packaging system. Melting temperature of the HDPE film used in this study was 126oC. The heat seal temperature was controlled and varied at around melting temperature of HDPE precisely. The mechanical property of the sealed films was measured by a T-shape peeling test. Development molecular structure at film interface for sealing was evaluated in a wide angle x-ray diffraction pattern and changing of molecular orientation relaxation corresponding with the mechanical peeling property. Thermal property was also analyzed by a differential scanning calorimetry (DSC). The weight fraction of melting region in heat seal process was estimated from the DSC thermograms. We discussed that the amount of melting region is related to the major factor to decide peeling properties of heat sealed HDPE film.
Charles J. O’Neil , Tony Listro , Amar S Nilajkar , Lawrence A. Acquarulo Jr., May 2010
An attempt was made to combine two existing technologies ƒ??nanocompositesƒ? and ƒ??crosslinkingƒ?. The goal of this work was to study the combined effects of nanoclay and crosslinking on the physical properties of polyamides. Tensile and flexural properties have been studied and reported. The effect of radiation dosage level on these properties has been looked at as well.The approach was to melt blend polyamide based polymers used in the medical industry with nanoclay and a crosslinking agent. The different polyamide based polymers used were nylon 12 and a polyether-block amide copolymer. The nanoclay used was Closite from Southern clay.
Polyphenylene ether is an engineering thermoplastic known for its excellent water resistance, dimensional stability and inherent flame retardancy. A triblock copolymer of polyphenylene ether-polysiloxane is produced by the oxidative coupling polymerization of 2,6-xylenol and eugenol-capped polysiloxane. This method of producing the copolymer is simpler than prior methods of preparing related copolymers by linking preformed polyphenylene ether and polysiloxane blocks. This paper describes the copolymer structure and the significant improvements in key properties such as impact resistance, flame retardancy and smoke generation obtained with the copolymer as compared to the polyphenylene ether homopolymer.
Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
Available: www.4spe.org.
Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.
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