Comparative investigation of the ultraviolet stabilization of polycarbonate/poly(acrylonitrile–butadiene–styrene) with different ultraviolet absorbers

When polycarbonate (PC)/poly(acrylonitrile–butadiene–styrene) (ABS) blends are exposed to outdoor conditions, they are mainly degraded by sunlight; this is known as photodegradation. It is the ultraviolet radiation in the sunlight that is responsible for the degradation of the blend. To stabilize the blend against the harmful ultraviolet radiation, ultraviolet absorbers (UVAs) are used. In this study, three different UVAs—Tinuvin 1577 (a hydroxyphenyl triazine type), Cyasorb 5411 (a benzotriazole type), and Uvinul 3030 (a cyanoacrylate type)—were compounded with a PC/ABS blend at 240°C with a twin‐screw extruder. Accelerated aging of the compounded sample was done by an Atlas Suntest containing xenon lamp. The degradation studies were performed with ultraviolet–visible spectroscopy, attenuated total reflectance/Fourier transform infrared spectroscopy, and yellowing index measurements. The molecular weight of the compounded sample was determined by gel permeation chromatography. It was found that hydroxyphenyl triazine type UVA showed the best results for decreasing the degradation products, oxidation rate, and yellowing of the PC/ABS blend. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Dynamic mechanical properties of polycarbonate and acrylonitrile–butadiene–styrene copolymer blends

Blends of polycarbonate (PC) and poly(acrylonitrile‐co‐butadiene‐co‐styrene) (ABS) with different compositions are characterized by means of dynamic mechanical measurements. The samples show phase separation. The shift in the temperatures of the main dynamic mechanical relaxation shown by the blend with respect to those of the pure components is attributed to the migration of oligomers present in the ABS toward the PC in the melt blending process. A comparison with other techniques (dielectric and calorimetric analysis) and the application of the Takayanagi three block model confirm this hypothesis. In all the studied blend compositions (ABS weight up to 28.6%) the PC appears as the matrix where a disperse phase of ABS is present. The scanning and transmission electron microscopy micrographs show that the size of the ABS particles increases when the proportion of ABS in the blend increases. The FTIR results indicate that the interaction between both components are nonpolar in nature and can be enhanced by the preparation procedure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1507–1516, 2002     

Characterization of oxidized cellulose with ultraviolet–visible spectroscopy

This article describes some properties and behavior of oxidized cellulose evaluated with ultraviolet–visible spectroscopy. Newly defined analytical parameters are described. Mechanisms of poly(1,4‐β‐D ‐anhydroglucuronic acid) degradation and destruction are formulated. The feasibility of using the same Staudinger–Mark–Houwink equation to calculate the degree of polymerization of cellulose and the degree of polymerization of oxidized cellulose is demonstrated. Utilization of ultraviolet–visible spectroscopy is shown for the optimization of oxidized cellulose production and aging. Advantages and limitations of this method are discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Observations of physical aging in a polycarbonate and acrylonitrile–butadiene–styrene blend

The effects of physical aging of a 75 : 25 PC/ABS blend have been studied using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). From DSC, two distinct peak endotherms at about 90°C and 110°C, which are associated with the glass transition of ABS (T_g,ABS) and PC (T_g,PC) components, respectively, were observed. When progressive aging was monitored at 80°C for over 1000 h, the changes in enthalpic relaxation, glass and fictive temperatures for the blend followed similar trends to those already seen in the literature for PC aged between 125 and 130°C. The rate of enthalpy relaxation was also comparable. The plot of peak endotherm against logarithmic aging time for the PC blend constituent, however, behaved quite differently from the linear relationship known for highly aged PC. The ABS peak component also appeared to be insensitive to aging. Both observations were confirmed to be statistically significant using analysis of variance methods. Using temperature modulated‐DSC, there is evidence that aging increases the blend miscibility as the T_g,PC shifts toward the stationary T_g,ABS during aging. Parallel FTIR investigations found oxidation of butadiene during aging to be even at this relatively low temperature, forming hydroxyl and carbonyl degradation products. The presence of ABS in the blend also appeared to have prevented the shifting from the trans‐cis to trans‐trans arrangement of the carbonate linkage, which is a well‐known phenomenon during elevated temperature aging of PC alone. Moreover, the carbonate linkage appears to have been at the lower energy, trans‐trans, arrangement prior to the aging process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Blends of acrylonitrile–butadiene–styrene/waste poly(ethylene terephthalate) compatibilized by styrene maleic anhydride

Waste poly(ethylene terephthalate) (PET) from thin bottles was blended with acrylonitrile–butadiene–styrene (ABS) copolymer in different proportions, up to 10 wt %. Styrene maleic anhydride (SMA) copolymer was used as a compatibilizer. The tensile strength and heat deflection temperature of the blend were higher than that of virgin ABS. Flexural modulus remained unaffected, although a slight decrease in impact property was observed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2593–2599, 2001     

Properties of acrylonitrile–butadiene–styrene/polycarbonate blends with styrene–butadiene–styrene block copolymer

The importance of alloys and blends has increased gradually in the polymer industry so that the plastics industry has moved toward complex systems. The main reasons for making polymer blends are the strengthening and the economic aspects of the resultant product. In this study, I attempted to improve compatibility in a polymer blend composed of two normally incompatible constituents, namely, acrylonitrile–butadiene–styrene (ABS) and polycarbonate (PC), through the addition of a compatibilizer. The compatibilizing agent, styrene–butadiene–styrene block copolymer (SBS), was added to the polymer blend in ratios of 1, 5, and 10% with a twin‐screw extruder. The morphology and the compatibility of the mixtures were examined by scanning electron microscopy and differential scanning calorimetry. Further, all three blends of ABS/PC/SBS were subjected to examination to obtain their yield and tensile strengths, elasticity modulus, percentage elongation, Izod impact strength, hardness, heat deflection temperature, Vicat softening point, and melt flow index. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2521–2527, 2004     

Recycling of blends of acrylonitrile–butadiene–styrene (ABS) and polyamide

The aim of this work is to evaluate routes to upgrade recycled engineering plastics, especially mixed plastics with acrylonitrile–butadiene–styrene copolymers (ABS) as the major component. A core‐shell impact modifier was successfully used to improve the impact strength of blends of ABS and ABS/polycarbonate (PC) blends recycled from the automotive industry. However, the presence of other immiscible components like polyamide (PA), even in small amounts, can lead to a deterioration in the overall properties of the blends. A styrene–maleic anhydride (SMA) copolymer and other commercial polymer blends were used to promote the compatibilization of ABS and PA. The core‐shell impact modifier was again found to be an efficient additive with regard to the impact strength of the compatibilized ABS/PA blends. The results obtained with fresh material blends were quite promising. However, in blends of recycled ABS and glass‐fiber‐reinforced PA, the impact strength did not exhibit the desired behavior. The presence of poorly bonded glass fibers in the blend matrix was the probable reason for the poor impact strength compared with that of a blend of recycled ABS and mineral‐filled PA. Although functionalized triblock rubbers (SEBS–MA) can substantially enhance the impact strength of PA, they did not improve the impact strength of ABS/PA blends because the miscibility with ABS is poor. The possibilities of using commercial polymer blends to compatibilize otherwise incompatible polymer mixtures were also explored giving promising results. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2535–2543, 2002     

Investigation of the electropolymerization of o‐toluidine and p‐phenylenediamine and their electrocopolymerization by in situ ultraviolet–visible spectroelectrochemistry

Under the conditions of potentiostatic electrolysis, the electropolymerization of o‐toluidine (OT) and para‐phenylenediamine (PPDA) and the electrocopolymerization between OT and PPDA on an indium tin oxide (ITO) conductive glass electrode at potentials of 0.7, 0.8, and 0.9 V were studied in detail by in situ ultraviolet–visible (UV–vis) spectrometry in 0.5 mol/L sulfuric acid media. It was shown that both OT and PPDA could be electropolymerized on the ITO electrode, which depended on the applied electrolysis potential and the concentration of the monomer. Furthermore, in situ UV–vis spectra indicated that the electrocopolymerization between OT and PPDA could happen. The presence of PPDA not only promoted polymerization but also accelerated polymerization, which was attributed to the formation of an intermediate result from the coupling of PPDA and the toluidine monomer cation radical. PPDA could be incorporated into the copolymer to make the copolymer have a phenazine or phenazine‐like cyclic structure, which was proven by the reflectance Fourier transform infrared spectra of the polymer and copolymer. The scanning electron microscopy morphology images of the polymers obtained showed that, in addition to accelerating polymerization, PPDA also could change the method of nucleation for the polymer to make the copolymer possess a fibrous surface morphology. The diameter of the fibroid copolymer was about 100 nm, and the length of that reached about 1000 nm. In the article, a newer concerned mechanism of copolymerization was proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Use of Fourier transform infrared and second derivative ultraviolet spectrometry in determining polystyrene–poly(4‐vinylpyridine) blend composition

Polymer blend usage has increased in recent years as the blends provide a convenient means for modifying polymer properties. It is often necessary to be able to determine the percentages or ratios of polymers present in a blend. One blend of interest is the immiscible blend of polystyrene (PS) and poly(4‐vinylpyridine) (P4VP). The percentages were determined by two methods: Fourier transform infrared (FTIR) spectroscopy and second derivative ultraviolet (UV) spectroscopy. The peak ratio versus percentage polymer technique was used in both methods. For FTIR, the ratio of the absorbance values of the out‐of‐plane C? H bending vibration of P4VP at 822 cm^?1 and the aromatic C ? C stretch for PS at 1493 cm^?1 were ratioed. For derivative UV, the vibrational structure of the aromatic secondary bands was used: 269 nm minimum for PS and the 271 nm maximum for P4VP. Both methods gave excellent and comparable results. The derivative UV determination had the advantage of requiring less sample due to its greater sensitivity. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2422–2426, 2005     

Boiling water aging of polycarbonate and polycarbonate/acrylonitrile–butadiene–styrene resin and polycarbonate/low‐density polyester blends

The effects of boiling water on the mechanical and thermal properties and morphologies of polycarbonate (PC), PC/acrylonitrile–butadiene–styrene resin (PC/ABS), and PC/low‐density polyester (PC/LDPE) blends (compositions of PC/ABS and PC/LDPE blends were 80/20) were studied. PC and the PC/ABS blend had a transition from ductile to brittle materials after boiling water aging. The PC/LDPE blend was more resistant to boiling water aging than PC and the PC/ABS blend. The thermal properties of glass‐transition temperature (T_g) and melting temperature (T_m) in PC and the blends were measured by DSC. The T_g of PC and PC in the PC/ABS and PC/LDPE blends decreased after aging. The T_g of the ABS component in the PC/ABS blend did not change after aging. The supersaturated water in PC clustered around impurities or air bubbles leading to the formation of microcracks, which was the primary reason for the ductile–brittle transition in PC, and the microcracks could not recover after PC was treated at 160°C for 6 h. The PC/ABS blend showed slightly higher resistance to boiling water than did PC. The highest resistance to boiling water of the PC/LDPE blend may be attributed to its special structural morphology. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 589–595, 2003     

Characterization and thermally stimulated depolarization current studies of rhodamine-dye-doped poly(acrylonitrile–butadiene–styrene) films

IR and UV-absorption spectra, and the thermally stimulated currents of pure and Rhodamine-6G-doped poly(acrylonitrile–butadiene–styrene) (Rhdoped ABS) films were investigated. Structural characteristics could be specified from these techniques. Both IR and UV-absorption studies revealed a modification of the structure of ABS on blending with Rhodamine 6G: Rh molecules are partially dispersed in the ABS matrix and partially attached as side groups to the ABS backbone. Thermally stimulated depolarization current (TSDC) studies confirmed this result. The results revealed that incorporation of Rh 6G in ABS locks the dipole in the ABS matrix after electric poling. The TSDC spectra have been found, depending on the polarization temperature, to be characterized by three peaks. The phenomenon of the existence of these current maxima is discussed and analysed in terms of dipolar and ionic relaxations.     

Kinetic investigation of thermooxidative degradation of poly(vinyl chloride)/acrylonitrile–butadiene–styrene blends by isothermal thermogravimetric analysis

The thermal degradation of poly(vinyl chloride)/acrylonitrile–butadiene–styrene (PVC/ABS) blends of different compositions was investigated by means of isothermal thermogravimetric analysis at temperatures of 210°–240°C in flowing atmosphere of air. The Flynn equation, the method of stationary point, and kinetic equation using the Prout–Tompkins model proved to be satisfactory in describing the thermooxidative degradation in the range of 5–30% conversions. The apparent activation energy E and preexponential factor Z were calculated for all compositions of PVC/ABS blends. The ratios E/ln Z are constant for pure and modified PVC and point to the unique mechanism of degradation process. Upon increasing the ratio of ABS in the PVC/ABS blend up to 50%, only the rate of the process is changed; the mechanism remains unchanged. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 833–839, 1999     

Fourier transform infrared and second derivative ultraviolet spectrometry in determining polystyrene‐poly(4‐methylstyrene) blend composition

Polymer blend usage has increased in recent years as the blends provide a convenient means for modifying polymer properties. It is often necessary to determine the percents or ratios of the polymers present in a blend. One blend of interest is the immiscible blend of polystyrene (PS) and poly(4‐methylstyrene) (P4MS). The percentages were determined by two methods: Fourier transform infrared (FTIR) spectroscopy and second derivative ultraviolet (UV) spectroscopy. The peak ratio versus percent polymer technique was used in both methods. For the FTIR, the ratio of the absorbance values for the out‐of‐plane C? H para‐substituted bending vibration of P4MS at 813 cm^?1 and the out‐of‐plane monosubstituted C? H bending vibration for PS at 757 cm^?1 were ratioed. For derivative UV, the vibrational structures of the aromatic secondary bands were used: the 269 nm minimum for PS and 275 nm minimum for P4MS. The derivative UV method gave considerably better results and also had the advantage of requiring less sample due to its greater sensitivity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3400–3403, 2006     

PEGylation of deuterohaemin–alanine–histidine–threonine–valine–glutamic acid–lysine and its influence on activity,stability, and aggregation

Deuterohaemin–alanine–histidine–threonine–valine–glutamic acid–lysine (DhHP‐6) is a synthetic heme‐containing peroxidase mimic that exhibits a high peroxidase enzyme activity. Compared to other microperoxidases, DhHP‐6 has a poor stability and tends to aggregate in aqueous solutions. In this study, poly(ethylene glycol) (PEG) was used to improve the properties of DhHP‐6. Factors that affected the PEGylation product yield were investigated. PEGylated DhHP‐6 (mPEG–DhHP‐6) was characterized by reversed‐phase high‐pressure liquid chromatography (RP‐HPLC), matrix‐assisted laser desorption/ionization time of flight mass spectra (MALDI‐TOF‐MS), and ultraviolet–visible (UV–vis) spectroscopy. The results show that the optimal PEGylation reaction conditions were achieved when the PEGylation was conducted in a borate buffer solution at pH 8.0 and 25°C for 4 h with a feeding ratio of 2 equiv of active PEG. After PEGylation, mPEG–DhHP‐6 showed a great improvement in its stability with little activity loss. The UV–vis spectra of DhHP‐6 and mPEG–DhHP‐6 in different pH solutions showed that the aggregation of DhHP‐6 was partly suppressed after PEGylation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Compatibility and thermal properties of poly(acrylonitrile–butadiene–styrene) copolymer blends with poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile)

The mechanical and heat‐resistant properties of acrylonitrile–butadiene–styrene (ABS) binary and ternary blends were investigated. The relationship of compatibility and properties was discussed. The results show that poly(methyl methacrylate) (PMMA) and styrene–maleic anhydride (SMA) can improve the thermal properties of conventional ABS. The Izod impact property of ABS/PMMA blends increases significantly with the addition of PMMA, whereas that of ABS/SMA blends decreases significantly with the addition of SMA. Blends mixed with high‐viscosity PMMA are characterized by higher heat‐distortion temperature (HDT), and their heat resistance is similar to that of blends mixed with SMA. For high‐viscosity PMMA, from 10 to 20%, it is clear that blends appear at the brittle–ductile transition, which is related to the compatibility of the two phases. TEM micrographs show low‐content and high‐viscosity PMMA in large, abnormally shaped forms in the matrix. Compatibility between PMMA and ABS is dependent on both the amount and the viscosity of PMMA. When the amount of high‐viscosity PMMA varied from 10 to 20 wt %, the morphology of the ABS binary blends varied from poor to satisfactory compatibility. As the viscosity of PMMA decreases, the critical amount of PMMA needed for the compatibility of the two phases also decreases. SMA, as a compatibilizer, improved the interfacial adhesiveness of ABS and PMMA, which results in PMMA having good dispersion in the matrix. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2652–2660, 2002     

Mechanical properties of acrylonitrile–butadiene–styrene copolymer/poly(l‐lactic acid) blends and their composites

As the material properties of acrylonitrile–butadiene–styrene copolymer (ABS) have an excessively wide margin for applications in automobile console boxes, ABS partly replaced with poly(l ‐lactic acid) (PLA) may be used for the same purpose with improved ecofriendliness if the corresponding deterioration of the material properties is acceptable through the choice of appropriate additives. ABS composites with 30 wt % renewable components (PLA and cellulose pulp) were prepared by melt compounding, and the material properties were examined as a function of the additive content. The changes in the mechanical properties of the ABS/PLA blends were examined after the addition of cellulose pulp and two clays [Cloisite 25A (C25A) and sodium montmorillonite] as well as these two clays treated with bis(3‐triethoxysilylpropyl)tetrasulfide (TESPT). The heat distortion temperatures of the composites were measured as a function of the content of the TESPT‐treated C25A. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40329.     

Compatibilization of polypropylene/Poly(acrylonitrile‐butadiene‐styrene) blends by polypropylene‐graft‐cardanol

The polypropylene‐graft‐cardanol (PP‐g‐cardanol) was prepared by reactive extrusion with polypropylene (PP) and natural renewable cardanol which could increase the interfacial energy of PP and inhibit the degradation of PP during the process of reactive extrusion and usage. In this article, PP‐g‐cardanol and polypropylene‐graft‐maleic anhydride (PP‐g‐MAH) were used as compatibilizers of the polypropylene (PP)/poly(acrylonitrile‐butadiene‐styrene) (ABS) blends. PP/ABS (70/30, wt %) blends with PP‐g‐cardanol and PP‐g‐MAH were prepared by a corotating twin‐screw extruder. From the results of morphological studies, the droplet size of ABS was minimized to 1.93 and 2.01 μm when the content of PP‐g‐cardanol and PP‐g‐MAH up to 5 and 7 phr, respectively. The results of mechanical testing showed that the tensile strength, impact strength and flexural strength of PP/ABS (70/30) blends increase with the increasing of PP‐g‐cardanol content up to 5 phr. The complex viscosity of PP/ABS (70/30) blends with 5 phr PP‐g‐cardanol showed the highest value. Moreover, the change of impact strength and tensile strength of PP/ABS (70/30) blends were investigated by accelerated degradation testing. After 4 accelerated degradation cycles, the impact strength of the PP/ABS (70/30) blends with 5 phr PP‐g‐cardanol decrease less than 6%, but PP/ABS (70/30) blends with 5 phr PP‐g‐MAH and without compatibilizer decrease as much as 12% and 32%, respectively. The tensile strength of PP/ABS (70/30) blends has a similar tendency to that of impact strength. The above results indicated that PP‐g‐cardanol could be used as an impact modifier and a good compatibilizer, which also exhibited better stability performance during accelerated degradation testing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41315.     

The influence of the internal structure of core–shell particles on poly(vinyl chloride)/(methyl methacrylate–butadiene–styrene) blends

Methyl methacrylate–butadiene–styrene (MBS) core–shell particles were prepared by grafting styrene and methyl methacrylate onto polybutadiene seeds via emulsion polymerization. All the MBS particles were designed with the same chemical composition, similar grafting degree but different internal structures. The difference in internal structure was realized by controlling the ratio of ‘external grafting’ and ‘internal grafting’ of styrene. The work focused on the influence of the internal structure of MBS core–shell particles on the properties of poly(vinyl chloride)/MBS blends. From transmission electron microscopy, three different internal structures were observed: rare sub‐inclusions, a large number of small sub‐inclusions and large sub‐inclusions. The results of dynamic mechanical analysis illustrated that the different internal structures greatly affected the glass transition temperature T_g of the rubber phase and the storage modulus of the core–shell particles. The notched Izod impact test results showed that the MBS with large sub‐inclusions had the lowest brittle–ductile transition temperature, while the transparency test revealed that the presence of sub‐inclusions in the rubbery phase reduced the transparency of the blend. Copyright © 2012 Society of Chemical Industry     

Investigation of acetyl ferrocene migration from hydroxyl‐terminated polybutadiene based elastomers by means of ultraviolet–visible and atomic absorption spectroscopic techniques

Migration and leakage of some mobile components in rocket propellant produces an inhomogeneous composition region at which migration takes place, which can lead to premature detonation, changes in ballistic characteristics, and so on. It is, therefore, important to be able to predict the behavior of low‐molecular‐weight mobile additives and to control the leakage of them from the propellant. At this point, our chief interest was to study the magnitude of the migration and to understand the factors that influence the migration process. In this study, the migration of a ferrocene‐based burning‐rate catalyst [acetyl ferrocene (AcF)] a from hydroxyl‐terminated polybutadiene (HTPB) based elastomer in the presence of a plasticizer (dioctyl adipate) was examined in accelerated aging conditions at 60°C for various time intervals. We also tried to minimize the migration of AcF from the loaded to the unloaded part by using an extra barrier layer consisting of polyfunctional aziridine (AST D45+) in addition to the HTPB–toluene diisocyanate composition. The migration enhanced with aging of the AcF and the barrier effects of the layer with intensified crosslink density to this migration were studied extensively. The migration was monitored by both ultraviolet–visible and atomic absorption spectroscopy (AAS) methods. A comparison of the data obtained from both of these methods was also done. The two techniques were found to be in agreement, and the Fe determinations from both methods were highly correlated, suggesting that the data were reliable, although the AAS data were found to be symmetrically somewhat higher. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1654–1661, 2005     

Effect of mixing process on electromagnetic interference shielding effectiveness of nickel/acrylonitrile–butadiene–styrene composites

This article reports the effect of the mixing process on the electromagnetic interference (EMI) shielding effectiveness of nickel/acrylonitrile–butadiene–styrene (ABS) composites. Nickel in either powder or filament form was used as the filler material. It was mixed with ABS by two mixing processes: one was the Brabender‐mixing method, in which nickel was mixed in the polymer melt by a strong shear at high temperatures, and the other was a simple dry mixing method performed in a centrifugal ball mill. Our results showed that the dry‐mixing method could produce EMI shielding effectiveness of 36 dB at the 3 vol % nickel filaments level. In contrast, we need 20 vol % nickel powder to exhibit some shielding effectiveness for the Brabender method. After the nondestructive X‐ray examination and four‐point probe resistivity measurements, we concluded that better EMI shielding effectiveness could be achieved when the mixing method provided a state of uniformity on the macroscale, but not on the microscale. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 128–135, 2005