Processibility and Miscibility Studies of Uncompatibilized Linear Low Density Polyethylene/Poly(Vinyl Alcohol) Blends (original) (raw)
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Characterization and properties of linear low density polyethylene/poly(vinyl alcohol) blends
2011
Kesan komposisi adunan, agen sambung-silang, radiasi alur elektron dan gabungan radiasi serta agen sambung silang ke atas sifat-sifat adunan polietilena linear berketumpatan rendah/poli(vinil alkohol) telah dikaji. Sambung silang disediakan menggunakan asid maleik dan 3-(trimetoksisilil)propil metakrilat sebagai agen sambung silang dan dikumil peroksida (DCP) sebagai pemula, sementara trimetilolpropana triakrilat (TMPTA) sebagai agen sambung silang yang dipilih untuk proses radiasi. The effect of blend ratio, crosslinking agent, electron beam irradiation and the combination of irradiation and crosslinking agent on the properties of linear low density polyethylene/poly(vinyl alcohol) blends were investigated. The crosslinking was prepared using maleic acid and 3-(trimethoxysilyl)propyl methacrylate as crosslinking agents and dicumyl peroxide (DCP) as initiator, while trimethylolpropane triacrylate (TMPTA) was crosslinking agent chosen for irradiation process
The compatibility of low-density polyethylene and poly(ethylene-co-vinyl acetate) containing 18 wt % vinyl acetate units (EVA-18) was studied. For this purpose, a series of different blends containing 25, 50, or 75 wt % EVA-18 were prepared by melt mixing with a single-screw extruder. For each composition, three different sets of blends were prepared, which corresponded to the three different temperatures used in the metering section and the die of the extruder (140, 160, and 180°C), at a screw rotation speed of 42 rpm. Blends that contained 25 wt % EVA-18 were also prepared through mixing at 140, 160, or 180°C but at a screw speed of 69 rpm. A study of the blends by differential scanning calorimetry showed that all the prepared blends were heterogeneous, except that containing 75 wt % EVA-18 and prepared at 180°C. However, because of the high inter-facial adhesion, a fine dispersion of the minor component in the polymer matrix was observed for all the studied blends with scanning electron microscopy. The tensile strengths and elongations at break of the blends lay between the corresponding values of the two polymers. The absence of any minimum in the mechanical properties was strong evidence that the two polymers were compatible over the whole range of composition. The thermal shrinkage of the blends at various temperatures depended mainly on the temperature and EVA-18 content.
Solution and Solid-State Blend Compatibility of Poly(vinyl alcohol) and Poly(methyl methacrylate)
The blend miscibility of poly(vinyl alcohol) and poly(methyl methacrylate) in N,N′-dimethylformamide solution was investigated by viscosity, density, ultrasonic velocity, refractive index, and UV and fluorescence spectra studies. Differential scanning calorimetry and scanning electron microscopy were used to confirm the blend miscibility in the solid state. Blends were compatible when the concentration of poly(vinyl alcohol) was greater than 60 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2415–2421, 2006
Compatibilization of regenerated low density polyethylene/poly(vinyl chloride) blends
Journal of Applied Polymer Science, 2008
The aim of this work is to study the valorization of regenerated low density polyethylene (rLDPE) by blending with PVC in the presence of chlorinated polyethylene (CPE) as compatibilizer. For this purpose, four rLDPE samples coming from neat or dirty wastes were used. They were obtained after milling, washing, and extrusion in a conventional recycling plant. They were first characterized in terms of physicochemical (density, melt flow index, water absorption, and level of oxidation by Fourier transform infrared spectroscopy) and mechanical (tensile and shore D hardness) properties. The effect of the ratio of PVC on these physical and mechanical properties was then investigated.
European Polymer Journal, 2005
Poly(vinyl alcohol) (PVA) (polymer A) and poly(N-vinylpyrrolidone) (PVP) (polymer B) are known to form a thermodynamically miscible pair. In the present study the conclusion on miscibility of PVA/PVP solid blends, confirmed qualitatively (DMTA, FTIR) and quantitatively (DSC, v AB = À 0.69 at 503 K) is compared with the miscibility investigations of PVA/PVP solution blends by the technique of dilute solution viscometry. The miscibility of the ternary (polymer A/ polymer B/ solvent) system is estimated on the basis of experimental and ideal values of the viscosity parameters k, b and [g]. It is found that the conclusions on miscibility or nonmiscibility drawn from viscosity measurements in dilute solution blends depend: (i) on the applied extrapolation method used for the determination of the viscosity interaction parameters, (ii) on the assumed definition of the ideal values and (iii) on the thermodynamic quality of the solvent, which in the case of PVA depends on its degree of hydrolysis. Hence, viscometric investigations of dilute PVA/PVP solution blends have revealed that viscometry, widely used in the literature for estimation of polymer-polymer miscibility can not be recommended as a sole method to presume the miscibility of a polymer pair.
Compatibilization of polyethylene/poly(propylene)/polystyrene blends
SUMMARY: The compatibilization of mixtures of polyolefins or of polyolefins with polystyrene using either liquid polybutadiene (l-PB)/organic peroxide or styrene-butadiene-styrene (SBS) block copolymers was investigated. Tensile impact strength was chosen as a measure of compatibility. Binary blends LDPE/high-impact polystyrene (HIPS) and LDPE/poly(propylene) (PP) as well as LDPE/HDPE/PP/HIPS blends were prepared by blending in the chamber of a Brabender Plasticorder. Composition of the blends corresponds to real commingled plastic waste. It was found that l-PB-based compatibilizer enhanced the impact strength of LDPE/HIPS blends with LDPE contents higher than 60 wt.-% only. Also SBS copolymer enhanced the impact strength of LDPE/PP blends with LDPE contents higher than 40 wt.-%. Both the compatibilizers substantially increased the toughness of LDPE/HDPE/PP/HIPS blends with composition similar to the municipal plastic waste. ZUSAMMENFASSUNG: Die Kompatibilisierung von Mischungen von Polyolefinen oder Polyolefinen mit Polystyrol unter Verwendung von entweder flüssigem Polybutadien (l-PB) und organischem Peroxid oder Styrol-Butadien-Styrol-Blockcopolymeren (SBS) wurde unterucht. Die Schlagzugzähigkeit wurde als Maß für die Verträglichkeit herangezogen. In einem Brabender-Plasticorder wurden binäre Blends aus LDPE und schlagzähem Polystyrol (HIPS) sowie LDPE und Polypropylen und LDPE/HDPE/PP/HIPS-Blends herge-stellt; die Zusammensetzung der Blends entsprach derjenigen von Kunststoff aus Hausmüll. Verträglichkeits-vermittler auf der Basis von l-PB steigerten die Schlagzähigkeit der LDPE/HIPS-Blends mit LDPE-Anteilen u ¨ber 60 Gew.-%. SBS erhöhte die Schlagzähigkeit der LDPE/PP-Blends mit LDPE-Anteilen u ¨ber 40 Gew.-%. Beide Verträglichkeitsvermittler verbesserten wesentlich die Zähigkeit der LDPE/HDPE/PP/HIPS-Blends mit einer der von Hausmüll entsprechenden Zusammensetzung.
Compatibility in Immiscible Poly(Vinyl Chloride)/Poly(Styrene) Blends
The morphology, orientation and mechanical studies of solvent cast poly (vinyl chloride) (PVC) /poly (styrene) (PS) blend films were carried out for various concentrations and draw ratios. Samples of pure PVC, PS and its blends were prepared using standard solution casting method.
Miscibility Improvement of LDPE/PVA Blends with Maleic Acid Additions
IOP Conference Series: Materials Science and Engineering
Mixing two types of polymers usually results in an immiscible blend, especially when using polymers with different polarities; therefore, a compatibilization process using suitable compatibilizers to improve miscibility is required. In this work, a low-density polyethylene (LDPE)/poly vinyl alcohol (PVA) blend was improved by adding maleic acid as compatibilizer. A twin-screw extruder was used to prepare blend samples, and the LDPE and PVA were mixed with different weight proportions. To identify the compatibility and miscibility of these blends, several tests were conducted, including Fourier transform infrared (FTIR), mechanical property observation, density testing, scanning electron microscopy (SEM), morphology examination, and differential scanning calorimetry (DSC). The results showed that mechanical properties and density were enhanced by the addition of maleic acid to the blends. SEM and Digital microscope results also showed good interaction between blend components when maleic acid was added to the blends.
Properties of Miscible Polymer Blends
1984
: The physical properties of a variety of miscible and partially miscible binary polymer blends were evaluated. Where possible, these properties were related to the intermolecular interactions responsible for blend miscibility. The properties of the miscible blends examined were found to be more strongly influenced by the blend composition and the inherent properties of the blend components than by the nature of the intermolecular interactions. For example, miscible polycarbonate/copolyester blends were found to thermally embrittle due to molecular relaxations when annealed for extended periods below the blend Tg; a phenomenon which is also observed for both pure components. For this same system, we have also demonstrated that the rate of hydrolysis of the polycarbonate component in the blend is substantially the same as is observed for pure polycarbonate. The inherently more stable polyester component can be used to produce blends with improved stability relative to polycarbonate. ...