聚碳酸酯—聚苯乙烯的反应性挤出共混研究(Ⅰ)

研究了噁唑啉官能化聚苯乙烯(RPS)与聚碳酸酯(PC)的共混反应,对反应性共混物及相应的非反应性共混物作了应力-应变试验及动态力学分析(DMA),并测定其接枝率及密度,发现反应性挤出共混提高了PS/PC共混物的力学性能。     

PS／PP反应性共混研究

本文研究了ＲＰＳ（含恶唑啉侧基苯乙烯）和ＭＰＰ的反应性共混以及ＲＰＳ－ＭＰＰ作为ＰＳ／ＰＰ相容剂的效果，考察了ＲＰＳ与ＭＰＰ比例、剪切作用大小对共混物性能的影响并从ＳＥＭ观察ＰＳ／ＰＰ共混物相态结构及其冲击强度测定的结果表明，ＲＰＳ－ＭＰＰ是ＰＳ／ＰＰ体系较好的相容剂。     

Synthesis of a graft copolymer from an ozonized polycarbonate and its application as a compatibilizer

The polycarbonate (PC)/polystyrene (PS) blend is an immiscible system. The use of copolymers as compatibilizers in blends is one approach that is being developed within the larger field of polymer alloys. In this study, PC was ozonized to create peroxides and hydroperoxides on the polymer chain. These functional groups under heating conditions were used to initiate the radical polymerization of styrene (vinyl monomers) to give graft copolymers. The first part of this study was dedicated to the examination of the kinetics of the styrene polymerization initiated by an ozonized PC. However, the structure of the graft copolymers was confirmed by IR spectroscopy, and the molecular weight of the PS graft chain was determined by gel permeation chromatography. The compatibilized bends were prepared by melt blending in an internal mixer. The morphologies of the PC/PS/graft copolymer blend were examined by transmission electron microscopy and were finer than those of an uncompatibilized blend. The tensile properties of these blends were also investigated. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation and characterization of syndiotactic polystyrene/ethylene‐propylene copolymer blends

The reactive compatibilization of syndiotactic polystyrene (sPS)/oxazoline‐styrene copolymer (RPS)/maleic anhydride grafted ethylene‐propylene copolymer (EPR‐MA) blends is investigated in this study. First, the miscibility of sPS/RPS blends is examined by thermal analysis. The cold crystallization peak (T_cc) moved toward higher temperature with increased PRS, and, concerning enthalpy relaxation behaviors, only a single enthalpy relation peak was found in all aged samples. These results indicate that the sPS/RPS blend is miscible along the various compositions and RPS can be used in the reactive compatibilization of sPS/RPS/EPR‐MA blends. The reactive compatibilized sPS/RPS/EPR‐MA blends showed finer morphology than sPS/EPR‐MA physical blends and higher storage modulus (G') and complex viscosity (η*) when RPS contents were increased. Moreover, the impact strength of sPS/RPS/EPR‐MA increased significantly compared to sPS/EPR‐MA blend, and SEM micrographs after impact testing show that the sPS/RPS/EPR‐MA blend has better adhesion between the sPS matrix and the dispersed EPR‐MA phase. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2084–2091, 2002     

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.     

聚碳酸酯与聚酯的相容性研究

分别采用熔融共混法和溶液共混法制备配比不同的聚碳酸酯／聚双(4-羟苯基)丙烷苯二甲酸酯(PC／PARL)。熔融共混法制备的：PC／PARL具有良好的透明性,DSC和DMA测试表明其具有单一的玻璃化转变温度,说明PC与PARL具有良好的相容性。溶液共混法制备的PC／PARL外观不透明,FTIR分析表明PC与PARL相容性不好。扭矩流变分析表明PC与PARL在熔融共混时相容是由于PC与PARL在高温下发生了酯交换反应,反应产物起到了增容剂的作用。SEM分析进一步证实了这一观点。     

Blends of bisphenol A polycarbonate and rubber‐toughened styrene–maleic anhydride copolymers

The morphology and mechanical properties of polycarbonate (PC) blends with rubber‐toughened styrene–maleic anhydride copolymer materials (TSMA) were investigated and compared with the properties of blends of PC with acrylonitrile–butadiene–styrene (ABS) materials. The PC/TSMA blends showed similar composition dependence of properties as the comparable PC/ABS blends. Polycarbonate blends with TSMA exhibited higher notched Izod impact toughness than pure PC under sharp‐notched conditions but the improvements are somewhat less than observed for similar blends with ABS. Since PC is known for its impact toughness except under sharp‐notched conditions, this represents a significant advantage of the rubber‐modified blends. PC blends with styrene–maleic anhydride copolymer (SMA) were compared to those with a styrene–acrylonitrile copolymer (SAN). The trends in blend morphology and mechanical properties were found to be qualitatively similar for the two types of copolymers. PC/SMA blends are nearly transparent or slightly pearlescent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1508–1515, 1999     

In situ compatibilization of PET/PS blends through reactive copolymers

Polymer blends of poly(ethylene terephthalate) (PET) and polystyrene (PS) are immiscible and incompatible, which has been well recognized. Styrene–glycidyl methacrylate (SG) copolymer has been synthesized by suspension polymerization and employed in this study as an in situ compatibilizer for the polyblends of PET and PS. This copolymer contains reactive epoxy functional groups that are able to react with PET end groups ? OH and ? COOH) under melt conditions to from SG-graft-PET copolymer. The presence of a small amount of phosphonium catalyst (200 ppm) accelerated the graft reaction and results in a better compatibilized blend. The compatibilized PET/PS blend has a smaller phase domain and higher viscosity than does the corresponding noncompatibilized blend. Mechanical properties of the compatibilized blends have also been improved significantly over the corresponding noncompatibilized blends. © 1993 John Wiley & Sons, Inc.     

Rheological hybrid effect in dually filled polycarbonate melt containing liquid crystalline polymer

Polycarbonate (PC)/liquid crystalline polymer (LCP) blends dually filled with glass fiber and nano‐SiO₂ were prepared by melt blending, with the use of a commercial Vectra A130 as the source of LCP and glass fiber. In these dually filled PC/LCP melts, rheological hybrid effect occurred, confirmed by the melt viscosity of the quadruple polymer blends decreased with increasing nano‐silica loading, influenced by the minor LCP phase in the blend. The drastic viscosity reduction closely correlates with the deformation and fibrillation of LCP droplets in the system. The LCP fibrillation was controlled jointly by the thermodynamic and hydrodynamic driving forces. Finally, the dually filled PC/LCP melt had decreased viscosity lower than those of pure PC, silica‐filled PC, and PC/Vectra A130 blends, and furthermore had decreased glass fiber breakage, shown by larger average aspect ratio than that in PC/Vectra A130 blends. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

Polymer blends of poly(trimethylene terephthalate) and polystyrene compatibilized by styrene‐glycidyl methacrylate copolymers

The compatibilizing effects of styrene‐glycidyl methacrylate (SG) copolymers with various glycidyl methyacrylate (GMA) contents on immiscible blends of poly(trimethylene terephthalate) (PTT) and polystyrene (PS) were investigated using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and ¹³C‐solid‐state nuclear magnetic resonance (NMR) spectroscopy. The epoxy functional groups in the SG copolymer were able to react with the PTT end groups (? COOH or ? OH) to form SG‐g‐PTT copolymers during melt processing. These in situ–formed graft copolymers tended to reside along the interface to reduce the interfacial tension and to increase the interfacial adhesion. The compatibilized PTT/PS blend possessed a smaller phase domain, higher viscosity, and better tensile properties than did the corresponding uncompatibilized blend. For all compositions, about 5% GMA in SG copolymer was found to be the optimum content to produce the best compatibilization of the blend. This study demonstrated that SG copolymers can be used efficiently in compatibilizing polymer blends of PTT and PS. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2247–2252, 2003     

The effect of UV‐irradiation and molten medium on the mechanical and thermal properties of polystyrene–polycarbonate blends

Polymer materials with improved properties can be obtained through polymer blends. As a polymer mixture is generally immiscible and incompatible, it is necessary to develop new methods to improve the interfacial adhesion. The aim of this work is to find formulations and associated processes to upgrade engineering polystyrene (PS) and polycarbonate (PC) polymer blends with the objective of using the best “process‐formulation” couple. In this study, blends of PS/PC were prepared in molten medium using reactive extrusion after UV‐irradiation. The effects of UV‐irradiation on some properties of blends under molten medium were investigated by differential scanning calorimetry (DSC), fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The data showed that the presence of polycarbonate in the blend increased the tensile strength and elongation at break with respect to pure PS. The mechanical properties of the blends were improved after irradiation. All irradiated blends are thermally more stable than those nonirradiated. Chemical changes can be clearly seen in FTIR spectra through two bands assigned to C?O and OH groups. The mutual influence between the PS/PC polymer blends compositions during UV‐irradiation was studied. PS and PC have different photo‐mechanisms due to the larger UV absorption of polystyrene and formation of more stable tertiary carbon radicals. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

（PE—HD／PE—LD）—g—GMA增容PC／PE—UHMW共混物的冲击性能与断面形态

采用反应挤出方法，制备了缺口冲击性能良好的(PE-HD／PE-LD)-g-GMA(甲基丙烯酸缩水甘油脂)增容PC／PE-UHMW共混物。当增容剂(PE-HD／PE-LD)-g-GMA用量为6份时，共混物的冲击强度达到最大值66kJ／m^2，比未增容PC／PE-UHMW提高了28．5kJ／m^2。冲击断面的SEM分析表明，增容剂的加入产生了反应性的增容效果，提高了两相之间的界面粘结力，促进了相的分散，对基体的剪切屈服形变有利，冲击性能得以改善。     

Dependence of the Morphology Development on the Kinetics of Reactive Melt Blending of Immiscible Polymers

Poly(methyl methacrylate) (PMMA) containing 50 wt% of anthracene (anth) labeled reactive PMMA chains [thus end‐capped by an anhydride (anh) or an isocyanate (NCO)] has been melt blended with polystyrene containing 33 wt% of chains end‐capped by an aliphatic amine (PS‐NH₂) at 180°C. Conversion of anth‐PMMA‐anh and anth‐PMMA‐NCO into PMMA‐b‐PS copolymers has been determined by SEC with a UV detector. The interfacial reaction mainly occurs in the initial mixing stage (?1.0 min), although at a rate which depends on the reactive groups attached to PMMA. Moreover, this interfacial reaction rate controls how the phase morphology is developed.     

Melt rheology of compatibilized polystyrene/low density polyethylene blends

Investigations have been made on the melt rheological behaviors of compatibilized blends composed of polystyrene, low density polyethylene and hydrogenated (styrene‐butadiene‐styrene) triblock copolymer used as a compatibilizer. The experiments were carried out on a capillary rheometer. The effects of shear stress, temperature and blending ratio on the activation energy for viscous flow and melt viscosity of the blends are described. The study shows that the viscosity of the blends exhibits a maximum or minimum value at a certain blending ratio. The activation energy for viscous flow decreases with increasing LDPE content. Furthermore, the concept of equal‐viscosity temperature is presented and its role in the processing of the blend is discussed. In addition, the morphology of the extrudate sample of the blends was observed by scanning electron microscopy and the correlation between the morphology and the rheological properties is explored. © 1999 Society of Chemical Industry     

Improved compatibility of high‐density polyethylene/poly(ethylene terephthalate) blend by the use of blocked isocyanate group

The blocked isocyanate group (BHI) was synthesized to improve the storage stability of HI (2‐hydroxyethyl methacrylate combined with isophorone diisocyanate) and characterized by Fourier transform infrared spectroscopy (FTIR). High‐density polyethylene grafted with the blocked isocyanate group (HDPE‐g‐BHI) was used as a reactive compatibilizer for an immiscible high‐density polyethylene/poly(ethylene terephthalate) (HDPE/PET) blend. A possible reactive compatibilization mechanism is that regenerated isocyanate groups of HDPE functionalized by BHI react with the hydroxyl and carboxyl groups of PET during melt blending. The HDPE‐g‐BHI/PET blend showed the smaller size of a dispersed phase compared to the HDPE/PET blend, indicating improved compatibility between HDPE and PET. This increased compatibility was due to the formation of an in situ graft copolymer, which was confirmed by dynamic mechanical analysis. Differential scanning calorimetry (DSC) analysis represented that there were few changes in the crystallinity for the continuous PET phase of the HDPE‐g‐BHI/PET blends, compared with those of the HDPE/PET blends at the same composition. Tensile strengths and elongations at the break of the HDPE‐g‐BHI/PET blends were greater than those of the HDPE/PET blends. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1017–1024, 2000     

Morphology and mechanical properties of reactive compatibilized polystyrene/ethylene‐vinyl acetate‐vinyl alcohol blends

A reactive compatibilizer, styrene‐maleic anhydride (SMA) was used to compatibilize the blends of polystyrene (PS) and ethylene‐vinyl acetate‐vinyl alcohol (EVAOH), which was synthesized from ethylene‐vinyl acetate (EVA) using transesterification reaction. The compatibilized blends with different compositions were prepared using a twin‐screw extruder and injection molded into the required test specimens. Morphology of Charpy impact‐fractured surfaces, tensile, and impact properties of the blends were investigated. Fourier‐transform infrared spectroscopy (FTIR) was also applied for specific samples to elucidate the presence of the functional groups reaction necessary for reactive compatibilization. The results of the ternary PS/EVAOH/SMA blends illustrate that the addition of SMA as a compatibilizer slightly reduce the elongation at break. From the impact‐fractured surfaces of the blends, it is evident that the morphology developed sizable pores when SMA was added into the blends. This might be attributed to the residual octanol‐1, produced from the synthesis of EVAOH, as there is a possibility of a reaction between hydroxyl groups in the octanol‐1 and the anhydride groups in the SMA. This disrupted the stability of the morphology and resulted in the decrease in the elongation, and hence, the tensile toughness. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 209–217, 2002     

Novel polymer blends from polyester and bio‐based cellulose ester

A strategy to reduce the dependence on petroleum‐based building blocks and the disposal concerns of solid wastes was proposed by developing a novel polymer blend from bio‐based cellulose acetate butyrate (CAB) and poly(trimethylene terephthalate) (PTT). The thermodynamic immiscibility and the thermal behaviors of the polymer melt blends were investigated. The interfacial properties were analyzed to provide the theoretical guidance to improve the compatibility of blends. A reactive compatibilizer, poly(trimethylene terephthalate)‐graft‐(maleic anhydride) (PTT‐g‐MA) was prepared from melt reaction and characterized with FTIR. The compatibilizer was melt blended into the CAB and PTT blends. The effects of different compatibilizers on the phase morphologies and mechanical properties of blends were characterized and the interfacial interactions were studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Polystyrene and polyester polyurethane elastomer blends compatibilized by SMA

Blends of polystyrene (PS) with polyester polyurethane elastomer (PU‐es) were compatibilized by addition of poly(styrene‐co‐maleic anhydride) (SMA) containing 7 wt % of maleic anhydride. Binary nonreactive (PS/PU‐es) blends, binary reactive (SMA/PU‐es) blends, and ternary reactive blends (PS/SMA/PU‐es) were prepared with 10 and 20 wt % of PU‐es. The maleic anhydride content in the ternary reactive blends was varied through addition of different SMA amounts from 0.5 to 5 wt %. Polyurethane in the blends was crosslinked by using dicumyl peroxide or sulfur to improve its mechanical properties. The experimental processing conditions, such as temperature and rotor speed in an internal mixer, were analyzed before blend preparation by processing the individual polymers, PS and SMA, and the PS/PU‐es nonreactive blend (90/10), to prevent the degradation of the polymer during melt mixing and to assure macroscopic homogeneity. The torque behavior during the mixture indicated a grafting copolymerization, which was responsible for the significant drop of the PU‐es domain size in the glassy matrix, as observed by scanning electronic microscopy (SEM). The miscibility of the glassy matrix, which was shown to be dependent on the composition and the phase behavior of ternary blends, became very complex as the SMA concentration increased, as concluded from dynamical–mechanical analysis. Blends containing 20 wt % of PU‐es presented an increase up to a factor of 2 in the deflection at break in relation to PS. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2297–2304, 2004     

Formation of co‐continuous PLLA/PC blends with significantly improved physical properties by reactive comb polymers

A kind of reactive comb (RC) polymer, which is constituted by poly(methyl methacrylate) backbone and side chains and a few epoxide groups that distribute randomly along the backbone, has been applied as compatibilizers for the thermodynamically immiscible poly(l ‐lactide) (PLLA)/polycarbonate (PC) blend (50/50, wt/wt). Phase morphology and physical properties of the compatibilized PLLA/PC blends are characterized by scanning electron microscopy, transmission electron microscopy, and tensile tests. It has been found that the morphologies of the PLLA/PC blends are significantly ameliorated with the addition of RC polymers. A type of PLLA/PC blend with stable co‐continuous morphology has been achieved by the incorporation of more than 3 wt % of RC polymers. The mechanical tests showed that the co‐continuous PLLA/PC blends have an excellent stiffness‐toughness balance with high modulus and significantly improved ductility. Especially, the elongation at break of the PLLA/PC blend compatibilized by 10 wt % of RC polymers is 10 times higher than that of neat PLLA, in which the blend exhibits a cocontinuous lamellar microstructure. Furthermore, the PLLA/PC blends with cocontinuous morphology exhibit dramatically improved thermal stability as compared to neat PLLA when the temperature is over the T_g of the PLLA phase. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46047.     

Miscibility evolution of polycarbonate/polystyrene blends during compounding

The miscibility evolution of polycarbonate/polystyrene (PC/PS) blends during the compounding process in three blending methods of industrial relevance, namely melt blending, remelt blending in a twin‐screw extruder and third melt blending in an injection molding machine, was investigated by measuring their glass transition temperatures (T_g) and their specific heat increment (ΔC_p). Differential scanning calorimetry (DSC) was used to examine nine blend compositions. Shifts in glass transition temperature (T_g) of the two phases in melt‐mixed PC/PS blends suggest partial miscibility of one polymer in the other. The observed solubility strongly depends on blend composition and blending method. The T_g measurements showed maximum mutual solubility around 50/50 composition. The miscibility of PC/PS blended after the third stage (melt injection molding) was higher than that after the first stages (melt extrusion) and the second stages (remelt extrusion).