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.
The SPE Library is just one of the great benefits of being an SPE member! Are you taking advantage of all of your SPE Benefits?
Andras Szucs, Andrea Adamne, Karoly Belina, Nick Schott, Dezso Csongor, May 2011
In our research we focus on thermoplastic composites of multiwall carbon nanotubes. Different composition of multiwall carbon nanotube and polymers were produced by a special mixing unit called Infinitely Variable Dynamic Shear Mixer (IDMX). ABS and polycarbonate polymers were used as matrix materials. Concentration series were manufactured and investigated. The prepared materials were characterized by scanning electron microscopy, mechanical and thermal properties of the materials were also determined. Correlation was found between the yield stress and the nanotube content.
Recycling of unfilled and reinforced poly (phenylene ether) (PPE) based thermoplastic elastomers (TPEs) was studied in detail. Improvement in mechanical properties upon recycling of the unfilled quaternary blend comprising of styrene-ethylene-butyllene-styrene (SEBS)/ethylene vinyl acetate (EVA)/PPE-PS (polystyrene) was correlated with the formation of crosslinked network. PPE based TPEs have been reinforced by incorporating nanofillers and with the formation of crosslinkinked TPEs or thermoplastic vulcanizates (TPVs). This study also provided an in-depth conceptual understanding of the recycle behavior PPE based TPE behavior upon reinforcement with silica nanoparticles and silica sol-gel precursors.
In integrated circuit (IC) packaging encapsulation, epoxy molding compound (EMC) adheres to mold surface after curing process. This phenomenon is called mold adhesion effect and it happens not only to thermosetting material but also to thermoplastic material. In this study, a mechanism designed with a mold that could measure normal adhesion force in injection molding process was successfully developed. The apparatus quantified the normal adhesion force. So engineers can use the measured adhesion force to understand the effectiveness of mold release agent and adhesion release coating.
Samik Gupta, Anil Bhowmick, Ashok Menon, Tapan Chandra, May 2011
The present work describes the thermo and photo-oxidative behavior of a series of novel thermoplastic elastomers (TPEs) from styrene-ethylene-butylene-styrene (SEBS), ethylene vinyl acetate (EVA) and poly (phenylene ether) PPE polystyrene (PS). A representative composition (based on the mechanical performance) of the quaternary blend was exposed at different temperatures for 2000 hours. Thermal degradation profiles of change in tensile strength and percent elongation at break of blends were monitored and half-life temperature was estimated based upon tensile strength. Photo-oxidative degradation was monitored through optical and mechanical measurements on the injection molded TPE. Change in chemical functionalities was monitored using ATR-FTIR.
Polycarbonate (PC) and poly(butylenes adipate-co-therephthalate) (PBAT) were melt blended using twin screw extruder. The phase morphology of PC/PBAT blends were observed by scanning electronic microscopy (SEM), indicated a homogeneous phase structure. The dynamic mechanical analysis revealed that there is shift of two tan ?? toward each other. It is thought that this is result from transesterification occurred in molten state. Also, thermogravimetric analysis showed that the thermal stability of PC/PBAT blends increases as PC contents increases. It suggests that PC can improve the thermal properties of PBAT in overall compositions.
Polylactide, polyester derived from renewable resources, can be synthesized using either L-lactide or D-lactide. A unique crystallization behavior of poly(L-lactide) (PLLA)/poly(D-lactide) (PDLA) stereocomplex(SC) was observed when a PLLA/PDLA blend was subjected to the specific melting conditions. Therefore, we tried to blend PLLA and PDLA at overall compositions to form PLA stereocomplexes. Moreover, impact modifier was added to enhance the mechanical properties such as impact strength. The presence of the SC in the PLLA matrix was verified by differential scanning calorimetry (DSC). Thermal and mechanical property of stereocomplexes were investigated by DSC, HDT, Izod impact tester, UTM.
Andrea Siebert-Raths, Hans-Josef Endres, Sicco de Vos, Gerald Schennik, May 2011
Next to the established packaging market the interest for biopolymers in technical application increases more and more. Especially automotive industry is interested in substituting oil-based polymers with biopolymers. In view of that, the focus of the work described here was on optimization of injection molding of polylactide (PLA) in order to improve material performance for technical applications. Furthermore, the effects of poly-D-lactide (PDLA) as nucleating agent, fibers and modifiers on material properties (e.g. heat resistance, mechanical properties) are reported.
New and innovative production systems are required in order to withstand the growing pressure of costs and competition in the plastics processing industry. Changeable manufacturing systems are one potential solution. These enable companies to adjust to repeatedly changing market conditions by themselves. At the University of Kassel's Institute of Materials Engineering, a changeable production system has been developed which is specially tailored to the requirements of plastics processing. The potential and limits of a changeable system for plastics processing are to be established on the basis of the pilot plant that is currently under construction.
Shia-Chung Chen, Jen-An Chang, Yu-Tseng Lin, Wen-Yang Shen, May 2011
The purpose of this study is to use externally wrapped coil induction heating to determine the practicality of its application in mold temperature control. A simulation was performed using the ANSYS software by the integration of both thermal and electromagnetic analysis modules. By experiment, the heating efficiency of coils in series was found to be 8.26C/s, while for parallel coils, it was 1.88C/s. Coils in series offers a much faster heating process. Both the simulation and experimental results are quite similar.
A compression molding system was custom built to impart directional flow properties in Wood plastic composites (WPC). Wood fiber (WF) and glass fiber (GF) of two different fiber lengths and HDPE of two different melt flow index (MFI) was used as matrix polymer to study their effect on mechanical properties of WPC. Tensile strength and flexural strength of the composites were determined. Experiments were also carried out to compare flexural strength of profile extruded and compression molded WPC with various WF contents to understand changes in mechanical property. The paper presents these results and compares with each other.
Fabian Beilharz, Christian Bonten, Peter Eyerer, May 2011
The quality of semi-finished products, as they are used in thermoforming, highly depends on the raw material used and their processing history. As a consequence, variations in sheet quality are often observed with their influence on processibility and product properties. Currently, there is no standard test for thermoforming sheet materials available, which means it is not possible to accurately predict how a material will behave in thermoforming. This study deals with the prediction of the thermoformability of sheet materials. A novel test method (Thermoforming Material Characterization TMC) to predict thermoformability is presented.
This study evaluates the in vitro degradation of scaffolds and films prepared from lactide based polymers and copolymers. The materials studied were poly(L-lactide)(PLLA), poly(DL-lactide)(PDLLA), a poly(L-lactide/æ-caprolactone) copolymer (PLCL) and a poly(DL-lactide/glycolide) copolymer (PLGA). The effect of the addition of bioactive particles such as hydroxyapatite and bioglass in the degradation kinetics was also investigated. It was found that the degradation in cast films was faster than the degradation in porous scaffolds; in addition, bioactive particles delayed the degradation of polymers studied.
Christoph Burgstaller, Bastian Priller, Wolfgang Stadbauer, May 2011
The aim of this work was to improve the interfacial adhesion between the matrix and the wood particles in polypropylene based wood plastic composites with the addition of chemical agents at the wood particle surface. We found, that with the addition of rather small, linear molecules, e.g. e-Caprolactone, interfacial adhesion, and therefore tensile strength, was improved up to 10% additionally to the benefits of a common maleic anhydride based compatibilizer. Furthermore, we found that also the chemical composition of the molecules added at the surface shows an influence at the extent of the improvement.
Poly(L-lactide/æ-caprolactone) (PLCL) was physically aged at 36§C and 40% of relative humidity (RH) to study the evolution of its structure and mechanical properties with time. Samples with an initial amorphous PLCL matrix, obtained by fast quenching from the melt were characterized before and during aging. The changes in structure and mechanical properties were studied using differential scanning calorimetry (DSC), X-Ray diffraction (WAXS) and tensile tests. As a result of aging, PLLA crystals were formed within the multiblock copolymer prompting to an increase in stiffness and to a loss of its elastomer-thermoplastic behavior of PLCL.
In this work, we consider the effect of the addition of functionalized silica to a series of poly (tetramethylene oxide) (PTMO) based polyurethanes. We have synthesized urethanes with different molecular weight soft segments (PTMO) and evaluated both structural and mechanical properties.
The mechanical data show a reinforcing effect occurs when the urethanes is filled. The FT-IR spectra show that the hard domain hydrogen bonding is unaffected by incorporation of silica. However, at elevated silica levels, the silica appears to attach onto the free carbonyls. These effects are dependent on the MW of the PTMO soft segments.
Jose-Ramon Sarasua, Erlantz Lizundia, Purificacion Landa, May 2011
The effects of temperature on crystallizations of Poly (L-lactide) (PLLA) have been studied by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and atomic force microscopy (AFM). The quantification of both ñ and ñ crystal structures into the crystallized PLLA samples was determined for 90 ?§C < Tc < 150 §C. The shortest crystallization times were achieved at Tc =107.1 §C, where both ñ and ñ crystal develop in the same proportion. The crystal structure changes have also been observed by WAXD . AFM images show a crystallization temperature dependence of surface roughness, spherulite diameter and nucleation density.
Gaurav Mediratta, Yaming Niu, Xiaoyu Sun, Srinivas Siripurapu, May 2011
Applications such as certain lighting components and face shields require clear materials that offer a combination of high heat resistance and low flammability. The flame performance of a new class of polycarbonates, ranging in Tg from 165?§C to 185?§C, was evaluated to understand their suitability for such applications. The new high heat polycarbonates showed superior flame performance in comparison to conventional and other high heat polycarbonates. Further, the flame performance was maintained in presence of pigments. The improvements in flame retardant properties did not adversely affect the use temperature with respect to color or molecular weight retention at elevated temperatures.
The effect of a multifunctional epoxy-acrylic-styrene copolymer as chain extender (CE) on the properties of PLA/Thermoplastic Starch (PLA/TPS) blends was investigated and its effect on the processing of blown films was clarified. The PLA/TPS blends were prepared by twin-screw extrusion, which comprised 27%TPS in the PLA matrix and 36% sorbitol/glycerol mixtures as plasticizers in TPS. The viscosity of the blends was dramatically increased by adding a small amount of CE. This is of great interest for film-blowing since this process requires materials with high melt strength, which has been demonstrated by the successful lab-scale film blown trials.
Nathalie Chapleau, Hongbo Li, Michel Huneault, May 2011
The biaxial stretchability of polylactide/thermoplastic starch blends was investigated. Blends were prepared via twin-screw extrusion. Water, glycerol and sorbitol were used as plasticizers. Interfacial modification was performed by grafting the PLA with maleic anhydride. A chain extender was also used. The addition of the grafted PLA yielded a finer TPS dispersed phase. These blends were drawn using a laboratory biaxial stretcher. The addition of TPS, grafted PLA and chain extender affected the biaxial stretchability of the neat PLA. Adding TPS to PLA resulted in a decrease of the tensile modulus but increased the elongation at break in some cases.
Ultrasonic cutting systems are employed with materials that are difficult to cut with standard mechanical systems. The cutting knife/edge typically vibrates at a frequency of 20-60 kHz, heating the substrate during the cutting and simultaneously sealing the cut edges. Polylactic acid (PLA), a biodegradable thermoplastic material derived from starch and sugar, is relatively brittle compared to polyethylene terephthalate (PET), which has similar mechanical properties. This brittleness is problematic during mechanical cutting, which produces micro-cracks that further embrittle the material.
84 countries and 60k+ stakeholders strong, SPE
unites
plastics professionals worldwide – helping them succeed and strengthening their skills
through
networking, events, training, and knowledge sharing.
No matter where you work in the plastics industry
value
chain-whether you're a scientist, engineer, technical personnel or a senior executive-nor
what your
background is, education, gender, culture or age-we are here to serve you.
Our members needs are our passion. We work hard so
that we
can ensure that everyone has the tools necessary to meet her or his personal & professional
goals.
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.