Thermoplastic Polyolefin Research Articles

Effect of Cooling Press on the Optical Transmission Through Photovoltaic Encapsulants

In certain laminators for poly (ethylene-co-vinyl acetate) (EVA) encapsulation process of photovoltaic modules, cooling press (CP) is applied to the module after encapsulation. Here, the effect of CP on the optical transmission through common PV encapsulants is studied. Interestingly, CP is shown to reduce drastically the scattering of the light between 400 and 700 nm traveling through the thermoplastic polyolefin (TPO)-based encapsulant. Post-annealing tests prove this effect to be stable at the temperature up to 85°C. This work has discovered a simple solution to mitigate the milky appearance of the TPO encapsulant and hence greatly enhanced its competitiveness against EVA.

Application of Coconut Fibres as Outer Eco-insulation to Control Solar Heat Radiation on Horizontal Concrete Slab Rooftop

Many countries alongside equator will experience excessive solar radiation, regardless the top and four sides of the buildings’ surfaces. Due to the modern architectural concept and fast growing industry and economic, hundreds of rows of two-to-three-story shops and office houses have been built on the central business districts. Those buildings built are equipped with flat bare and uninsulated concrete rooftop. Only few of flat rooftops are equipped with numerous un-eco-insulation developed in the world such as asphalt roll membranes, single-ply rubber membranes, Ethylene Propylene Diene Monomer (EPDM), and Thermoplastic Polyolefin. This paper deals with the use of coconut fibres to build thermal insulation on concrete slab roofings and the experimental measurements of roof surface and indoor air temperatures derived from dynamic climatology of solar radiation. Monthly average temperatures on rooftop concrete slab and room air temperatures were conducted. Coconut fibres will be considered as natural sustainable insulator with the following aspects: practicing to respect natural materials within the built environment, promoting less harzardus roofing insulation of the material used, limiting the impacts on the urban-built atmosphere, and preserving cooling energy demand by mitigating the flat concrete rooftop thermal onto the room. The room air thermal saving covered by coconut fibres is around 2.8o – 3.1oC different, and the rooftop surface thermal saving with coconut fibres is 13oC different, compared to conventional bare concrete slab roofings. The energy consumption reduction is around 3% (average) and 9% (maximum).

A new approach to construct segregated structures in thermoplastic polyolefin elastomers towards improved conductive and mechanical properties

A novel approach for the development of conductive elastomeric composites with improved electrical performance and mechanical properties is provided.

자동차 내장재용 열가소성 폴리프로필렌에 적용되는 선처리제용 친환경 수분산 폴리우레탄-우레아의 제조 및 성질

The significance of thermoplastic polyolefin polypropylene (PP) lies in its potential to replace polyvinyl chloride (PVC), the most widely used material for automobile interiors (door trim, dash board), which discharges harmful compounds in certain conditions. Another benefit of PP (0.855 amorphous 0.946 crystalline g/cm) is its low density compared to that of PVC (1.1-1.45 g/cm), which reduces vehicle weight. Market demand for eco-friendly water-based adhesive/coating material is rising significantly as a substitute for solvent-based adhesive/coating material which emits VOC and causes harmful working conditions. 232 * To whom correspondence should be addressed. E-mail: kimhd@pusan.ac.kr http://cleantech.or.kr/ct/ doi: 10.7464/ksct.2014.20.3.232 pISSN 1598-9721 eISSN 2288-0690 This is an Open-Access article distributed under the therms of the Ceative Commens Attribution Non-Commercial License (http://creativecommons.org/licences/ by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is property cited.. 자동차 내장재용 열가소성 폴리프로필렌에 적용되는 선처리제용 친환경 수분산 폴리우레탄-우레아의 제조 및 성질 233 Under such context, in this study, a series of eco-friendly waterborne polyurethane-urea primer (a paint product that allows finishing paint to adhere much better than if it were used alone) for hydrophobic PP were prepared from different mix of DMPA content, NCO/OH molar ratio, various wt% of silicone diol and various soft segment content, among which DMPA of 21 mole %, NCO/OH molar ratio of 1.2, modified silicone diol of 5 wt% and soft segment content of 73 wt% led to good adhesion strength. Additionally, the incorporation of optimum content of additives (0.5 wt% dispersing agent, 0.5 wt% levelling agent, 1.5 wt% antifoaming agent, 3.0 wt% matting agent) into the optimum waterborne polyurethane-urea also enabled good stability, levelling, antifoaming and non-glossy.

Developing a Novel Hyperbranched Polymer-Modified PP/Clay Nanocomposite: Characteristics Investigation

Polypropylene, as a thermoplastic polyolefin, possesses advantageous physical, mechanical and thermal characteristics, but also suffers from disapproving lesser properties such as poor dye- and coat-ability. Herein, nanoclay particles and a polyester-amide-based hyperbranched polymer are utilized to improve paint-ability along with mechanical properties. XRD and SEM results rationalize the idea that maleic anhydride-modified polypropylene and hyperbranched polymer together improve the nanoclay dispersion. The corresponding idea of “molecular skateboards” is also developed via rheology measurements. DMA data demonstrate that mechanical characteristics of the hyperbranched polymer-modified samples remain intact or even improved comparing neat polypropylene and contact angle measurements reveal reduction in θ values.

Physical properties of irradiated thermoplastic elastomeric olefins based on (devulcanized rubber)/(high crystalline polypropylene) formulations

This work aims to produce thermoplastic elastomeric olefins based on devulcanized waste rubber (DR) and polypropylene (PP) compatibilized with poly(ethylene‐propylene‐diene monomer) (EPDM). The coupling of DR/PP in varying proportions with EPDM was investigated by Fourier‐transform infrared, X‐ray diffraction, and scanning electron microscopy techniques. A comparative study was established to evaluate the influence of EPDM content and radiation dose on the physical, mechanical, and thermal performance of DR/PP/EPDM composites. It was found that the synergism of EPDM incorporation and irradiation conditions up to 100 kGy remarkably decreased the PP Tm value, indicating a promotion in the PP and radiation sensitivity. J. VINYL ADDIT. TECHNOL., 21:33–41, 2015. © 2014 Society of Plastics Engineers

Modeling of Multilayered Sheets for Thermoforming Applications

During the last decades, automotive industry has to meet many environmental constraints and to reduce the cost and the energy conception. Giving their mechanical properties and low manufacturing cost, thermoplastic multilayered materials have proven to be an adequate solution for such applications. In this paper, the particular combination of Thermoplastic PolyOlefin (TPO) sheets and Polypropylene (PP) foams is considered. The mechanical behavior of each material is studied and the multilayered material response is predicted and compared to measurements at a 120°C temperature. Despite the transversely isotropic behavior of the TPO sheets and the very high stretch ranges, the obtained results are very convincing and the used models proved to be very reliable.

Evaluating different alkyl ammonium modified organoclays in preparation of TPO nanocomposites with supercritical CO2

This article examines the chemical structures of the surfactants associated with organically modified montmorillonites in order to understand how differences in the structure may influence the final properties of the nanocomposite materials. Five organically modified montmorillonites with different surfactants were examined in materials prepared using a novel technique for thermoplastic polyolefin nanocomposites, using supercritical CO2 as a processing aid. The chain length and the number of alkyl chains attached to the quaternary ammonium surfactant were the main variables of study aimed at changing the interactions of an organoclay with compatibilizer and/or polymer matrix due to the CO2 treatment. The goal of this work was to improve the exfoliation of the dispersed organoclay. The intermediate masterbatch containing organoclay and compatibilizer as well as the final TPO nanocomposites were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and rheological analysis. The results showed that of the systems tested, significant changes in the state of exfoliation after processing with the supercritical fluid occurred only for surfactants possessing dialkyl tails and exhibiting a paraffin type arrangement within the montmorillonite. POLYM. COMPOS., 35:1592–1602, 2014. © 2013 Society of Plastics Engineers

Mechanical Behavior and Fracture Toughness Evaluation of Multiphase Polymer Nanocomposites Using Impact and J-Integral via Locus Method

Fracture behaviors of fibrillar silicate clay (MMT) filled thermoplastic polyolefin (TPO) containing polypropylene (PP) blended with ethylene-propylene-diene monomer (EPDM) were systematically investigated using impact test method and J-integral by locus method. Drastic increase in impact strength is observed for all developed compositions and generally shows higher value for the selected phases containing dispersed nanoclay in PP matrix. A fracture mechanics approach has been adopted by mode I test, and the effects of specimen geometry have been investigated. Increase in interlaminar fracture energy value, Gc, and J-integral value, Jc, is marked as the crack propagated through the composite; that is, a rising “R-curve” is observed. Toughness measurements revealed that the fracture toughness increased with increasing clay content reaching maximum at 3 wt% of clay than pure PP. Moreover, enhancement of fracture toughness was more remarkable than that of stiffness. The fracture surfaces taken from different specimens were observed for exploring the fracture mechanisms using transmission electron microscopy (TEM) revealed a strong particle-matrix adhesion.

The Preparation and Properties of TPV/Organoclay Composites

Dynamic vulcanized thermoplastic olefin/ organoclay composites were prepared in this paper. The morphology of the composites is studied with WAXD, which suggest organoclay shows good dispersion in TPV. The prepared TPV/organoclay composites improved mechanical properties significantly, the thermal property were also changed when organoclay is added. Besides, the content of curing agent and the addition of oil on the influence of properties were discussed.

Effects of photodegradation and thermal ageing on the scratch behavior of uncoated thermoplastic olefin

This study examined the effects of exposure to thermal ageing and weathering conditions on the scratch resistance of an uncoated thermoplastic polyolefin system over a period of 1800h. A flatbed scanner and scanning electron microscopy were used to observe the surface characterization and morphology for the scratch-induced damage of the aged TPO systems. The number of oxygen containing polar functional groups, amount of talc, crystallinity and discoloration on the TPO surface increase with increasing ageing time. At the same time, the number of hydrocarbon groups decreases. These findings suggest that the hydrocarbon groups locally undergo oxidation on the TPO surface due to thermal ageing and weathering. The abovementioned changes lead to an increase in scratch resistance and performance.

Ageing of surface treated thermoplastic polyolefins

Thermoplastic polyolefin panels were treated with a flame, flame & water, and accelerated thermo molecular adhesion process (ATmaP) treatment. XPS, contact angle and adhesion test (pull off) results were acquired over a one year period to determine the changes in the elemental composition, surface energy and adhesion strength respectively over time. All surface-treated thermoplastic polyolefin samples showed a sharp decline in adhesion strength up to an ageing period totalling 6 months. The decline in adhesion strength was correlated with a decline in the nitrogen-containing constituents and C–O functional groups at the surface and a decline in surface energy for the flame & water-treated sample. There was no significant change in adhesion strength for all samples for ageing periods greater than 6 months. ATmaP-treated thermoplastic polyolefin outperformed the other two surface treatments in adhesion strength tests due to ATmaP retaining nitrogen-based functional groups (mainly nitrogen oxides) over the year long study. This retention of functionality allowed for a slower ageing process for ATmaP-treated surfaces in comparison to the other surface treatments.

Does long term exposure to radon gas influence the properties of polymeric waterproof materials?

The technical state of buildings and the quality of the indoor environment depend on the quality of the waterproofing course and on the properties of the insulating materials that are applied, in particular on their durability, long-term functional reliability and resistance to corrosive effects of the subsoil. Underground water chemistry and soil bacteria are well-known corrosive agents. Our investigations indicate that the ageing process of waterproof materials can be significantly accelerated by alpha particles emitted by radon and radon progenies which are present in soil gas. Materials commonly available on the building market, e.g. LDPE and HDPE of various densities, PVC, TPO (thermoplastic polyolefin), PP (polypropylene) and EPDM were selected for our experimental study. The preliminary results for 3-year exposure to radon gas show a decrease in tensile strength to 60%, elongation to 80% and hardness to 95% for samples based on PE. The diffusion coefficient of radon for samples based on PVC decreased to 20% of the initial value after 1-year exposure to radon and soil bacteria.

Gas permeability of thin dense films from polymer blend of thermoplastic elastomer and polyolefin

ABSTRACTStretched thin films composed of a thermoplastic elastomer, a polystyrene‐block‐poly(ethylene butylene)‐block‐polystyrene triblock copolymer (SEBS), and polyolefins, poly(ethylene‐co‐ethylacrylate) and poly(ethylene‐co‐propylene), were obtained by blow‐molding, uniaxial stretching, and cooling to room temperature and the gas permeability of the stretched films was investigated. When the as‐blown annealed film was subjected to uniaxial stretching in the machine direction, PO2 and PN2 increased with an increase in the stretching ratio K and approached a constant value at high stretching ratios. In addition, PO2/PN2 decreased gradually with K and approached a value of 2.95–3.0. The reason for this unique gas permeation behavior is that the molecular mobility of poly(ethylene butylene) chains in a direction normal to the film increases and reaches an equilibrium state at around K = 4.5. The change in gas permeability of the stretched films can be explained using a deformation model for the SEBS matrix. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39386.

Foaming behavior of microcellular thermoplastic olefin blends

The influence of reactive compatibilization on the foaming behavior of thermoplastic olefin blends of polypropylene and a metallocene-catalyzed ethylene octene copolymer was investigated. A batch setup was used to foam the samples using carbon dioxide as blowing agent. Solubility measurements were performed to determine the relative amount of gas concentration in the pressurized polymers before foaming. A microscopic method based on the back-scattered electron imaging technique was used to determine the respective locations of the bubbles and the dispersed elastomeric domains in the polypropylene matrix. It was shown that the bubbles are preferentially formed in the dispersed elastomeric domains. A clear relationship was established between the microstructure of the blends prepared with different levels of compatibilizer and the final cellular morphology of the microcellular thermoplastic olefin foams. The initial morphology of the blends was also altered by quiescent coarsening as well as shear-induced phase coalescence, and the impact of the morphological transitions on the cellular structure of the resulting foams was investigated. Dynamic shear and transient measurements of elongation were performed to characterize the viscoelastic behavior of the thermoplastic olefins. It was shown that the addition of a compatibilizer resulted in enhanced viscoelastic properties at low frequencies as well as increased levels of strain hardening, especially at low strain rates. The reactive compatibilization could significantly improve the melt foamability through control of the blend microstructure as well as enhancement of the melt rheological properties.

Thin dense films from polymer blend of thermoplastic elastomer and polyolefin by uniaxial stretching

AbstractThin dense films composed of a thermoplastic elastomer [polystyrene‐block‐poly(ethylene butylene)‐block‐polystyrene triblock copolymer (SEBS)] and two polyolefins, poly(ethylene‐co‐ethylacrylate) and poly(ethylene‐co‐propylene), were obtained by blow molding, uniaxial hot stretching, and cooling to room temperature. In the resulting films, the dispersed polyolefin phase formed a 3D‐network structure which constrained the elastic recovery of the SEBS matrix phase. The presence of this network structure was a key factor in forming the thin dense films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

열가소성 폴리올레핀으로 구성된 범퍼 후방 보 개발에 관한 연구

Recently, the application of the plastic material to automotive components and structures has steadily increased to satisfy demands on the saving of overall weight and the improvement of energy efficiency. The objective of this paper is to investigate the development of a bumper backbeam using a thermoplastic olefin (TPO). The bumper back-beam was designed to be manufactured from the injection molding process. In order to obtain a proper design of the bumper back-beam, three-dimensional finite element analyses were performed for various design alternatives. Stress-strain curves for different strain rates were measured by high speed tensile tests of the TPO to consider strain rate effects in the FEA. The influence of the sectional shape and the rib formation on the contact force-intrusion curves, the deflection and the energy absorption rate of the bumper back-beam was examined. From the results of the examination, a proper design of the bumper back-beam was acquired. The bumper back-beam consisting of TPO was fabricated from the injection moulding process and the vibration welding. Pendulum crash tests were carried out using the fabricated bumper back-beam. The results of the tests showed that the designed bumper back-beam can satisfy requirements of the federal motor vehicle safety standard (FMVSS). Through the comparison of the previously designed bumper back-beam with the newly designed bumper back beam, it was noted that the weight of the designed bumper back-beam is lighter than that of the previously designed bumper back beam by nearly 16 %. In addition, it was considered that the newly designed bumper back beam can improve recycling of the bumper back-beam.

Dow introduces new polyolefin elastomer for automotive TPOs

The Dow Chemical Company is introducing Engage™ XLT, a new grade of polyolefin elastomer for thermoplastic olefins (TPOs) used for automotive interior and exterior components. When compounded with polypropylene, this new material delivers a ‘combination of benefits not previously possible’ with other TPO impact modifiers, the company says.

Preparation and properties of peroxide dynamically vulcanized polypropylene/ethylene‐propylene‐diene monomer/zinc dimethacrylate thermoplastic olefin

AbstractAttempts were made to prepare the polypropylene (PP) /ethylene‐propylene‐diene monomer (EPDM) blends with zinc dimethacrylate (ZDMA) via peroxide dynamic vulcanization. PP was melt‐mixed with EPDM and ZDMA at different compositions (PP/EPDM/ZDMA, i.e., 70/30/0, 70/30/3, 70/30/6, and 70/30/9, w/w/w) using an internal mixer at 50 rpm rotor speed. The addition of ZDMA improved the rheological properties of the resulting materials in the melt state. The morphological studies revealed that the addition of ZDMA led to an improvement of size reduction and distribution uniformity for crosslinked EPDM phase. ZDMA showed a positive effect on the mechanical properties of the PP/EPDM/ZDMA composites, particularly on the toughness and extensibility. With the incorporation of ZDMA, the izod impact strength and the elongation of PP/EPDM/ZDMA composites increased from 41 kJ/m2 to 72 kJ/m2 and 110% to 495%, respectively. The crystallization behaviors analysis indicated that the addition of ZDMA promoted the nucleation process of PP but the crystallinity of the PP phase was decreased at the meantime. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

PP/EPDM-based dynamically vulcanized thermoplastic olefin with zinc dimethacrylate: Preparation, rheology, morphology, crystallization and mechanical properties

Dynamically vulcanized thermoplastic olefin (TPO) based on polypropylene (PP)/ethylene-propylene-diene (EPDM) loaded with zinc dimethacrylate (ZDMA) was prepared. The addition of ZDMA significantly improved the complex viscosity of the resulting material in the melt state, as determined from rheological analysis. Dynamic mechanical analysis (DMA), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were performed to evaluate the structure, as well as to characterize the morphology formed during dynamic vulcanization. The ZDMA improved the crosslinking of the rubber phase and resulted in crosslinked rubber particles with dimensions within 200 nm. The addition of ZDMA improved the compatibility between rubber and PP phases, which contributed to the enhanced mechanical and rheological properties. The crystallization behavior analysis indicated that the addition of ZDMA promoted the nucleation process of PP, but a higher ZDMA content showed a negative effect on the crystallinity of the PP component. Remarkable improvements in toughness and extensibility of PP/EPDM/ZDMA composites were achieved.