Effects of europium (III) acetylacetonate doping on the miscibility and photoluminescent properties of polycarbonate and poly(methyl methacrylate) blends

Blends stand out as simple and cheap materials with unique properties. The miscibility of blends formed by bisphenol-A polycarbonate (PC) with poly(methyl methacrylate) (PMMA) doped with europium (III) acetylacetonate have been studied by differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and photoluminescent (PL) spectroscopy. DSC studies demonstrated that undoped PC/PMMA blends obtained by precipitation method present one glass transition temperature, evidencing their apparent miscibility. FTIR spectra revealed synergic effects in the PC/PMMA system as well as the incorporation of the Eu³⁺ complex. TGA analysis suggested that the Eu³⁺ complex remains preferably in the PC micro-phase. SEM analysis showed that europium (III) acetylacetonate is homogeneously distributed within the blend and PL spectra evidenced the photoluminescence of Eu³⁺ incorporated into the blend.     

Single-Phase blends of polycarbonate and poly(phenyl methacrylate)

Miscibility studies on blends of polycarbonate (PC) and poly(phenyl methacrylate) (PPMA) were undertaken by means of differential scanning calorimetry (DSC), dynamic mechanical, and dielectric relaxation methods. PC and PPMA were mixed by dissolving in tetrahydrofuran (THE) and subsequently coprecipitated in methanol. DSC studies showed a single glass transition (T_g) that shifts systematically with composition. These T_gs are reproducible in repeated DSC heating cycles, suggesting true miscibility of the pair. The dry PC and PPMA pellets were melt mixed in a Mini-Mixer/Molder. The extrudates were compression molded. These melt-mixed PC/PPMA blends exhibited glass like transparency and also showed a single T_g in the DSC scans. The true miscibility of PC and PPMA was further confirmed by dynamic mechnaical and dielectric relaxation methods. The net birefringence has been reduced substantially because of the opposite sign of the itrinsic birefringence of PC and PPMA molecules. At the 12/88 PC/PPMA, the birefringence remains zero at all draw ratios, indicating the achievement of birefringence free polymer alloys.     

Blends of polycarbonate with poly(methyl methacrylate): Miscibility,phase continuity,and interfacial adhesion

Dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) concurrently show that polycarbonate (PC)/poly(methyl methacrylate) (PMMA) blends have a two-phase structure. The differences between the T_gs of parent polymers and the T_gs of conjugate phases, determined by both DMTA and DSC, indicate a limited miscibility of components and allow the approximate composition of conjugate phases to be calculated. The Flory-Huggins interaction parameter calculated by using these data assumes values about 0.035 ± 0.010. Phase inversion occurs in an interval close to the 50/50 composition, though the molar masses and melt viscosities of the polymers were rather different. Partial miscibility of components ensures interfacial adhesion capable of sustaining the stress transfer between phases up to fracture. Yield stress of the blends is very close to values foreseen by the rule of mixtures. A specific feature of the blends studied is that the addition of 10 to 20 vol% of PMMA to PC increases the strain at break and work to fracture, which are rather low for the PC used. The enhanced capability of the blends to absorb mechanical energy is probably linked to plastic deformation of the dispersed PMMA.     

Miscibility,phase behavior,and mechanical properties of ternary blends of poly(vinyl chloride)/polystyrene/chlorinated polyethylene-graft-polystyrene

The effectiveness of chlorinated polyethylene-graft-polystyrene (CPE-g-PS) as a polymeric compatibilizer for immiscible poly(vinyl chloride)/polystyrene (PVC/PS) blends was investigated. The miscibility, phase behavior, and mechanical properties were studied using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Izod impact tests, tensile tests, and scanning electron microscopy (SEM). DSC and DMA studies showed that PVC is immiscible with chlorinated polyethylene (CPE) in CPE-g-PS, whereas the PS homopolymer is miscible with PS in CPE-g-PS. The PVC/PS/CPE-g-PS ternary blends exhibit a three-phase structure: PVC phase, CPE phase, and PS phase that consisted of a PS homopolymer and PS in CPE-g-PS. The mechanical properties showed that CPE-g-PS interacts well with both PVC and PS and can be used as a polymeric compatibilizer for PVC/PS blends. CPE-g-PS can also be used as an impact modifier for both PVC and PS. SEM observations confirmed, after the addition of CPE-g-PS, improvement of the interfacial adhesion between the phases of the PVC/PS blends. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 995–1003, 1998     

Miscibility and mechanical properties of tetrafunctional epoxy resin/phenolphthalein poly(ether ether ketone) blends

Phenolphthalein poly(ether ether ketone) (PEK‐C) was found to be miscible with uncured tetraglycidyl 4,4′‐diaminodiphenylmethane (TGDDM), which is a type of tetrafunctional epoxy resin (ER), as shown by the existence of a single glass transition temperature (T_g) within the whole composition range. The miscibility between PEK‐C and TGDDM is considered to be due mainly to entropy contribution. Furthermore, blends of PEK‐C and TGDDM cured with 4,4′‐diaminodiphenylmethane (DDM) were studied using dynamic mechanical analysis (DMA), Fourier‐transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). DMA studies show that the DDM‐cured TGDDM/PEK‐C blends have only one T_g. SEM observation also confirmed that the blends were homogeneous. FTIR studies showed that the curing reaction is incomplete due to the high viscosity of PEK‐C. As the PEK‐C content increased, the tensile properties of the blends decreased slightly and the fracture toughness factor also showed a slight decreasing tendency, presumably due to the reduced crosslink density of the epoxy network. SEM observation of the fracture surfaces of fracture toughness test specimens showed the brittle nature of the fracture for the pure ER and its blends with PEK‐C. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 598–607, 2001     

Mechanical properties of recycled PVC blends with styrenic polymers

The aim of this study is to improve the performance of blends made from recycled polyvinyl chloride (PVC), coming from credit card waste, so that these blends can be used for those applications that must fulfil some requirements with regard to mechanical properties and stability with temperature alterations. With this aim in mind, two polymers of styrenic origin have been combined: styrene acrylonitrile (SAN) and acrylonitrile butadiene styrene (ABS). These polymers are characterized by a satisfactory balance of mechanical properties and thermal stability. PVC blends with both virgin and recycled styrenic polymers have been studied throughout the entire range of compositions. The prior degradation of the recycled materials has been studied by means of Fourier transformed infrared spectroscopy (FTIR).The behavior of the observed T_g values has been analyzed using differential scanning calorimetry (DSC), and the existence of partial miscibility between the different components has been studied. The mechanical properties have been determined using tensile and Charpy impact tests. The thermal stability of the PVC blends with temperature changes has been determined using the Vicat softening temperature (VST). Finally, the fracture surface of the various blends has been analyzed using scanning electron microscopy (SEM). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2464–2471, 2006     

Blends of poly(hydroxyether of bisphenol A) and polycarbonate: in situ polymerization preparation,miscibility, and transreaction

In the presence of polycarbonate (PC), the polymerization of diglycidyl ether of bisphenol A (DGEBA) and bisphenol A in the melt was initiated to prepare blends of poly(hydroxyether of bisphenol A) (phenoxy) and PC. The polymerization reaction started from the initially homogeneous ternary mixture consisting of DGEBA, bisphenol A, and PC; phenoxy/PC blends with PC content up to 20 wt % were obtained. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were employed to characterize the miscibility of the as-polymerized blends. All the blends displayed separate glass transition temperatures (T_g's), that is, the blends were phase-separated. The formation of a two-phase structure is considered to result from phase separation induced by polymerization. This result is consistent with the immiscibility established through solution- and melt-blending approaches. The insolubility of the as-polymerized blends showed that crosslinking between the components occurred. Both Fourier-transform infrared (FTIR) and solid ¹³C-nuclear magnetic resonance (¹³C-NMR) spectroscopic studies demonstrated a transreaction between the components and in situ polymerization of DGEBA and bisphenol A in the presence of PC, which yielded a phase-separated, transreacted material. The results of this work provide a contrast to those of the transreacted phenoxy/PC blends based on conventional blending methods; however, the transreaction in the present case occurred at a much lower temperature (180^oC), at which polymerization blending was carried out. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1181–1190, 1999     

Thermal and morphological properties of SA/HPMC blends

Sodium alginate (SA) was blended with varying amounts of hydroxypropyl methylcellulose (HPMC) viz., 10, 20, and 30 wt % by solution casting process. Thus, the obtained blends were characterized by using different analytical techniques such as differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microcopy (SEM). FTIR studies reveal the hydrogen bond formation between hydroxyl groups of SA and HPMC polymer chains. DSC analysis shows single glass transition temperature (T_g) for SA/HPMC blends indicating compatibility and physical interaction between SA and HPMC polymer chains. TGA analysis indicates variation of thermal stability of SA with change in compositions of HPMC. SEM studies reveal uniform distribution of second phase in the blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Ternary blends of acrylic rubber,poly(butylene terephthalate), and liquid crystalline polymer: Influence of interactions on thermal and dynamic mechanical properties

The ternary blends of acrylate rubber (ACM), poly(butylene terephthalate) (PBT), and liquid crystalline polymer (LCP) were prepared by varying the amount of LCP but fixing the ratio of ACM and PBT, using melt mixing procedure. The influence of interactions on thermal and dynamic mechanical properties of the blends was investigated over the complete composition range. The techniques applied were Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetry (TG), and dynamic mechanical analysis (DMA). The FTIR spectroscopy analysis showed reduction in the intensity of the peak corresponding to epoxy groups of ACM with increasing heating time at 290°C. This implies that there is a chemical reaction between the epoxy and end groups of PBT and LCP. Glass transition temperature (T_g) and melting temperature (T_m) of the blends were affected depending on the LCP weight percent in the ACM/PBT blend, respectively. This further suggests the strong interfacial interactions between the blend components. In presence of ACM, the nucleating effect of LCP was more pronounced for the PBT phase. The thermogravimetric study showed improved thermal stability for the blends with the increasing LCP content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3904–3912, 2006     

Compatibility study of chlorinated polyethylene/ethylene methacrylate copolymer blends using thermal,mechanical, and chemical analysis

Blends of chlorinated polyethylene (CPE) elastomer and ethylene methacrylate copolymer (EMA) in various compositions were studied for their compatibility using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and Fourier transform infrared (FTIR) spectroscopy techniques. Irrespective of measurement techniques used, all blends showed a single glass transition temperature (T_g) lying in between the T_g of control polymers in both DSC and DMA. Glass transition temperatures of blends obtained from DSC were in consistency with Couchman–Karasz equation. Also, the T_g obtained from both DSC and DMA are above the “rule of mixing” line of the two control polymers. These results from thermal analysis clearly indicate some compatibility between the two polymers. Furthermore, compatibility of CPE/EMA blends were also been investigated by FTIR spectroscopy and scanning electron microscopic analysis. A shifting of characteristic C? Cl stretching peak of CPE and C?O stretching peak of EMA toward lower wave number indicate the presence of specific interaction between the two polymers. Mechanical properties like tensile strength, modulus at 100% elongation, elongation at break, and hardness were observed above the line of additivity drawn between the two control polymers, which corroborate compatibility between CPE and EMA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40316.     

The effect of graft copolymers of maleic anhydride and epoxy resin on the mechanical properties and morphology of PP/ABS blends

In this work, maleic anhydride‐grafted polypropylene (PP‐g‐MAH) and maleic anhydride‐grafted poly(acrylonitrile‐butadiene‐styrene) (ABS‐g‐MAH) at 2 : 1 mass ratio were added as a compatibilizer in the PP/ABS blends. The compatibilizing effect was evaluated by adding the graft copolymers together with epoxy resin/imidazole curing agent (E51/2E4MZ). The reaction in reactive extrusion, morphological structure, and properties of PP and ABS blends were investigated by using infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X‐ray spectrum, transmission electron microscope (TEM), dynamic thermomechanical analysis (DMA), differential scanning calorimetry (DSC), and mechanical properties tests. The results showed that the compatibilizing effect was greatly improved because of the addition of the graft copolymers together with epoxy resin/imidazole curing agent (E51/2E4MZ) because the link structure of PP‐g‐MAH and ABS‐g‐MAH was formed by the reaction of anhydride group with epoxy group catalyzed by the imidazole. The size of the dispersed phase decreased dramatically, the interfacial adhesion between ABS particles and PP matrix was improved, and the tensile strength and flexural modulus of the PP/ABS blends increased further. The optimizing properties were obtained at 3 phr E51/2E4MZ. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40898.     

Artificial weathering effect on the structure and properties of polypropylene/polyamide‐6 blends compatibilized with PP‐g‐MA

The degradation of uncompatibilized and compatibilized PP/PA‐6 (70/30 wt %) with PP‐g‐MA under accelerated UV light was investigated using Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, melt flow index (MFI) tester, tensile test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). FTIR analysis of the structure of the compatibilized and uncompatibilized blends after exposure to UV light showed the formation of photoproducts corresponding to both components. The MFI and mechanical results obtained revealed that photooxidation started primarily in PA‐6 rather than PP. In addition, the uncompatibilized blends exhibited a higher degradation rate compared to neat polymers for long exposure time, and the addition of PP‐g‐MA increased slightly their ageing rate in accordance with TGA data. Further, DSC analysis showed an increase in the crystallinity index and a decrease in the melting temperature of PP and PA‐6 after UV exposure either as neat polymers or as blend components. SEM micrographs of the cryo‐fractured surfaces of the samples illustrated the formation of cracks and fractures after UV irradiation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41722.     

Miscibility behaviour of bisphenol-A polycarbonate and poly(para-chlorostyrene)

The miscibility behaviour of bisphenol-A polycarbonate (PC) and poly(para-chlorostyrene) (PpCIS) has been investigated. Special attention has been paid to the influence of the molar mass of PpCIS. Molar masses varying from 10 to > 1,000 kg/mol were used. The blends were studied by differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and scanning and transmission electron microscopy (SEM and TEM). It was concluded that the blends of all three PpCIS grades and PC phase separate. In the low concentration region, some intermixing was found, especially for the blend with the low molar mass PpCIS. The most important effect of lowering the molar mass of PpCIS was an acceleration of the phase separation. The combination of SEM with electron probe X-ray microanalysis (EPMA) gave qualitative information on the miscibility behaviour and was found to be a useful extension of routine microscopy techniques used in blend studies.     

Miscibility enhancement of PP/PBT blends with a side‐chain liquid crystalline ionomer

Side‐chain liquid crystalline ionomer (SLCI) containing sulfonic acid groups with a polymethylhydrosiloxane main‐chain was used in the blends of polypropylene (PP) and polybutylene terephthalate (PBT) as a compatibilizer. The crystalline behavior, morphological, and mechanical properties of the blends were investigated in detail by differential scanning calorimetry (DSC), polarizing optical microscope (POM), Fourier transforms infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Revealed by the shift of T_m in DSC thermogram and the shift of the absorbed peak in FTIR spectra, specific interaction led to stronger interfacial adhesion between these phases, which resulted in much finer dispersion of the minor PBT phase in PP matrix. The SLCI containing sulfonate acid groups acted as physical crosslinking agent along the interface, which compatibilized PP/PBT blends. The mechanical property of the blends including 4 wt % SLCI contents was better than that of other SLCI contents in the blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Study on the properties of polyethylene–octene elastomer/wood flour blends

In the present study, the properties of metallocene polyethylene–octene elastomer (POE) and wood flour (WF) blends were examined by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), an Instron mechanical tester, and scanning electron microscopy (SEM). The results showed that the mechanical properties of POE were obviously lowered, due to the poor compatibility between the two phases, when it was blended with WFs. A fine dispersion and homogeneity of WF in the polymer matrix could be obtained when acrylic acid‐grafted POE (POE‐g‐AA) was used to replace POE for manufacture of the blends. This better dispersion is due to the formation of branched and crosslinked macromolecules since the POE‐g‐AA copolymer had carboxyl groups to react with the hydroxyls. This is reflected in the mechanical and thermal properties of the blends. In comparison with a pure POE/WF blend, the increase in tensile strength at break was remarkable for the POE‐g‐AA/WF blend. The POE‐g‐AA/WF blends are more easily processed than are the POE/WF blends, since the former had a lower melt viscosity than that of the latter. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1919–1924, 2003     

Novel strategy for ternary polymer blend compatibilization

A novel strategy for compatibilization of ternary polymer blends was described. PP (polyolefins)/PA6 (engineering plastics)/PS (styrene polymers) was selected as a model ternary blend system, and the compatibilization effect was investigated by means of SEM, rheometer, dynamic mechanical thermal analysis and mechanical testing. The results indicated that, as a ternary polymer blend compatibilizer, styrene and maleic anhydride dual monomers melt grafted polypropylene [PP-g-(MAH-co-St)] showed more effective compatibilization in the PP/PA6/PS ternary blend system than PP-g-MAH, PP-g-St and their mixture. The good compatibilizing effect of PP-g-(MAH-co-St) can be explained by two mechanisms. One is the in situ formation of [PP-g-(MAH-co-St)]-g-PA6 copolymer at the PP/PA6 interface, and the other is that it also contains styrene blocks, resulting in chemical affinity with PS and PP homopolymers.     

Phase morphology and interfacial characteristics of polycarbonate/acrylonitrile‐ethylene‐propylene‐diene‐styrene blends compatibilized by styrene‐maleic anhydride copolymers

Blends of polycarbonate (PC) and acrylonitrile ‐ ethylene‐propylene‐diene‐styrene (AES) were reactive compatibilized by styrene‐maleic anhydride copolymers (SMA). The changes in phase morphology and interfacial characteristics of the blends as a function of maleic anhydride content of SMA and the concentration of compatibilizer have been systematic studied. The occurrence of reaction between the terminal hydroxyl groups of PC and the maleic anhydride (MA) of compatibilizer was confirmed by fourier transform infrared (FTIR) spectroscopy. A glass transition temperature (T_g) with an intermediate value between T_g(AES) and T_g(PC) was found on differential scanning calorimeter (DSC) curves of PC/AES blends compatibilized with SMA contains high levels of MA. Furthermore, at lower compatibilizer content, increase of the compatibilizer level in blends result in decreasing gap between two T_gs corresponding to the constituent polymers. Small angle X‐ray scattering (SAXS) test results indicated that compatibilizer concentration for the minimum of blend interface layer's thickness was exactly the same as it was when compatibilized PC/AES blend exhibited optimal compatibility in DSC test. The observed morphological changes were consistent well with the DSC and SAXS test results. A new mechanism of interfacial structural development was proposed to explain unusual phenomena of SMA compatibilized PC/AES blends. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42103.     

Miscibility and phase behavior in thermosetting blends of polybenzoxazine and poly(ethylene oxide)

Thermosetting polymer blends composed of polybenzoxazine (PBA-a) and poly(ethylene oxide) (PEO) were prepared via in situ curing reaction of benzoxazine (BA-a) in the presence of PEO, which started from the initially homogeneous mixtures of BA-a and PEO. Before curing, the BA-a/PEO blends displayed the single and composition-dependant glass transition temperatures (T_g's) in the entire blend composition, and the equilibrium melting point depression was also observed in the blends. It is judged that the BA-a/PEO blends are completely miscible. The miscibility was mainly ascribed to the contribution of entropy to mixing free energy since the molecular weight of BA-a is rather low. However, phase separation occurred after curing reaction at the elevated temperature, which was confirmed by differential scanning calorimetry (DSC) and scanning electronic microscopy (SEM). It was expected that the PBA-a/PEO blends would be miscible since PBA-a possesses a great number of phenolic hydroxyls in the molecular backbone, which are potential to form the intermolecular hydrogen bonding interactions with oxygen atoms of PEO and thus would fulfill the miscibility of the blends. To interpret the experimental results, we investigated the variable temperature Fourier transform infrared spectroscopy (FTIR) of the blends via model compound. The FTIR results indicate that the phenolic hydroxyl groups could not form the efficient intermolecular hydrogen bonding interactions at the elevated temperatures (e.g. the curing temperatures), i.e. the phenolic hydroxyl groups existed mainly in the non-associated form in the system. Therefore, the decrease of the mixing entropy still dominates the phase behavior of thermosetting blends at the elevated temperature.     

Morphology,dynamic mechanical,and electrical properties of bio‐based poly(trimethylene terephthalate) blends,part 2: Poly(trimethylene terephthalate)/poly(ether esteramide)/polycarbonate blends

Bio‐based poly(trimethylene terephthalate) (PTT) and poly(ether esteramide) (PEEA) blends were prepared by melt processing with varying weight ratios (0–20 wt %) of polycarbonate (PC). The blends were characterized by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), polarized light microscopy (PLM), and transmission electron microscopy (TEM). Electrostatic performance was also investigated for those PTT blends since PEEA is known as an ion conductive polymer. DMA suggests that PC is miscible with PEEA and selectively goes into PEEA phase in case of ternary blends of PTT/PEEA/PC. The glass transition temperature (T_g) for PC/PEEA is well predicted by Gordon Taylor equation. Addition of PC retards the electrostatic decay performance of PTT/PEEA blends by restricting the motion of ions in PEEA through increasing the T_g of PEEA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of the molecular structure of polyurethane elastomers on the thermomechanical properties of PUE/PC blends

Polyurethane elastomers (PUEs) based on 4,4′‐diphenylmethane diisocyanate (MDI), 1,4‐butanediol (BDO) and two kinds of aliphatic polycaprolactone (PCL) diols with molecular weight of 1000 Da and 2000 Da have been synthesized and melt‐blended with polycarbonate (PC). The compatibility of PC and PUEs was investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The results indicated that the glass transition temperature (T_g) of PC decreased by 0–40°C when 0–10 wt % of PUEs incorporated into the PC matrix. Phase separation in the blends was not detected by means of DSC characterization, but measurements of DMA and SEM indicated that phase separation existed in the blends of PC and PUEs synthesized with 1000 Da PCL‐diol. As for PUEs/PC blend in which 2000 Da PCL‐diol as PUEs' soft segments, it turned from completely compatible to partially when the NCO/OH ratio for the PUEs prepolymer was increased from 2 : 1 to 4 : 1. The compatibilities of PC and PUEs were greatly influenced by the molecular weight of polyols and the ratio of NCO/OH in the PUE prepolymer, higher molecular weight of polyols and lower NCO/OH ratio resulted in better compatibility. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012