Changes in the interfacial properties of PC/SAN blends with compatibilizer

Block copolymers of polycarbonate‐b‐poly(methyl methacrylate) (PC‐b‐PMMA) and tetramethyl poly(carbonate)‐b‐poly(methyl methacrylate) (TMPC‐b‐PMMA) were examined as compatibilizers for blends of polycarbonate (PC) with styrene‐co‐acrylonitrile (SAN) copolymer. To explore the effects of block copolymers on the compatibility of PC/SAN blends, the average diameter of the dispersed particles in the blend was measured with an image analyzer, and the interfacial properties of the blends were analyzed with an imbedded fiber retraction (IFR) technique and an asymmetric double cantilever beam fracture test. The average diameter of dispersed particles and interfacial tension of the PC/SAN blends were reduced by adding compatibilizer to the PC/SAN blends. Fracture toughness of the blends was also improved by enhancing interfacial adhesion with compatibilizer. TMPC‐b‐PMMA copolymer was more effective than PC‐b‐PMMA copolymer as a compatibilizer for the PC/SAN blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2649–2656, 2003     

Preparation and properties of PC/SAN alloy modified with styrene‐ethylene‐butylene‐styrene block copolymer

A polycarbonate (PC)/ poly (styrene‐co‐acrylonitrile) (SAN) alloy modified with styrene‐ethylene‐butylene‐styrene (SEBS) block copolymer was prepared and the influence of SEBS content, PC content, and types of modifier on Izod notched impact strength, tensile strength, flexural strength, and Vicat softening temperature was studied. The results showed that the addition of SEBS could obviously increase the Izod notched impact strength and the elongation at break and decrease the tensile and flexural strength and Vicat softening temperature. PC/SAN alloy modified with SEBS had better mechanical properties than the PC/SAN alloy modified with ABS. DSC analysis and SEM photographs revealed that the SEBS was not only distributed in the SAN phase but also distributed in PC phase in a PC/SAN/SEBS alloy while the ABS was mainly distributed in SAN phase in a PC/SAN/ABS alloy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Influence of acrylic content in PBA‐SAN on the mechanical properties of PBA‐SAN and PBA‐SAN/SAN blends

The effects of different acrylic rubber (PBA) contents in core‐shell structured rubbery acrylate‐g‐poly (styrene‐acrylonitrile) (PBA‐SAN) on the mechanical properties of PBA‐SAN and PBA‐SAN/SAN blends were systematically investigated. Fourier transform‐infrared spectroscopy (FTIR) and scanning electron microscope (SEM) were used to characterize the structure and morphology of PBA‐SAN and PBA‐SAN/SAN blends, respectively. It was found that the mechanical properties of PBA‐SAN and PBA‐SAN/SAN blends strongly depended on the PBA content: largely improved impact strength and elongation at break were observed when adding PBA‐SAN with high PBA content. However, the loss in rigidity and heat distortion temperature were accompanied. Specifically, both PBA‐SAN and PBA‐SAN/SAN blends with 60 wt% PBA exhibited a good balance between toughness and rigidity, which indicating PBA‐SAN with 60 wt% PBA was the most suitable impact modifier. J. VINYL ADDIT. TECHNOL., 24:262–267, 2018. © 2016 Society of Plastics Engineers     

Rheological,mechanical and thermal properties of propylene‐ethylene block copolymer/polyalphaolefins blends

The rheological, thermal, and mechanical properties of propylene–ethylene block copolymer (PPB) blends with predominantly atactic molecular structure of low molecular weight polypropylene and propylene copolymers with either ethylene or 1‐butene (APAO) have been studied. It has been found that blend properties depend on comonomer type, content, and molecular weight of APAO as well as blend composition. APAO having ethylene comonomer showed better miscibility with PPB than the other ones, and high comonomer content of APAOs gave dramatic increase in impact strength over 30 wt%. It has been concluded that APAO can be used as an effective modifier of PPB. POLYM. ENG. SCI., 47:1905–1911, 2007. © 2007 Society of Plastics Engineers     

Rheological and mechanical properties of PEO/block copolymer blends

Small quantities of block copolymers from two families, styrene‐butadiene‐methylmethacrylate (SBM) and methylmethacrylate‐butylacrylate‐methylmethacrylate (MAM) have been added to a polyethylene oxide (PEO) in order to improve its processability, namely increasing its elastic modulus without increasing too much its shear viscosity. The copolymers contain one block of polymethylmethacrylate (PMMA) that is compatible with PEO; the other blocks create nano phases, dispersed in the PEO matrix. Considerable efforts were devoted to finding the best blending method, either melt processing or solution casting. PEO is very sensitive to shear, and was found to degrade both in the bulk and in solution. Degradation, which cannot be avoided, was quantified through intrinsic viscosity measurements. The rheological characterization of blends containing 1, 2, and 5 wt% block copolymer was carried out. The elastic modulus was found to increase more than the complex viscosity. Blends obtained by solution casting technique gave better results. The elongational viscosity obtained for one blend containing 5 wt% of SBM showed a slight increase with respect to the pure PEO. Mechanical properties were then investigated, through tensile tests and dynamic mechanical analysis in flexion and in torsion; the copolymer generally enhanced the mechanical properties. POLYM. ENG. SCI., 45:1385–1394, 2005. © 2005 Society of Plastics Engineers     

Effect of matrix SAN in ABS/PMMA blends

The effect of the molecular weight and acrylonitrile (AN) content of the styrene–acrylonitrile copolymer (SAN) on the morphology, mechanical properties, and rheological properties of acrylonitrile–butadiene–styrene terpolymer/poly(methyl methacrylate) (ABS)/PMMA (60/40 by weight) blends were studied. When the AN content of matrix SAN (32%) was close to that of graft SAN (30%) AN, rubber particles existed separately. However, with matrix SAN having 35% AN, rubber particles showed tendency to agglomerate each other. With increasing molecular weight of matrix SAN, impact strength, ultimate elongation, and abrasion resistance of the blend generally increased. Yield strength increased with molecular weight at a constant AN content of matrix SAN, and it decreased with the decrease of AN content in spite of the increasing molecular weight of SAN. Melt properties, rather than the morphological and mechanical properties, were more sensitive to the AN content, rather than the molecular weight of matrix SAN. © 1994 John Wiley & Sons, Inc.     

AN含量对PVC/SAN共混物相容性的影响

采用乳液聚合技术合成了一系列不同丙烯腈（AN）含量的苯乙烯-丙烯腈（SAN）共聚物,将其与聚氯乙烯（PVC）熔融共混,形成PVC/SAN共混物,并引入增塑剂邻苯二甲酸二辛酯（DOP）。通过动态力学分析仪（DMA）和扫描电子显微镜（SEM）对共混物的玻璃化转变温度和相结构进行表征,考察不同AN含量对PVC/SAN共混物相容性的影响。     

Experimental and computational study on structure development of PMMA/SAN blends

Structure development in PMMA/SAN28 blends was studied experimentally with small-angle light scattering (SALS) and computationally with a diffuse-interface model based on the Cahn-Hilliard theory. All three stages of phase separation were observed with SALS. The diffusion coefficient was derived from the initial stage, while the evolution of the interface thickness was derived from all stages. The coarsening kinetics is more dominated by hydrodynamics in the late stage than in the intermediate stage of the phase separation. This is confirmed by the computational study which revealed that the coarsening becomes dominated by hydrodynamics when the capillary number is reduced from 10 to 0.5. A quantitative comparison between the experimental and numerically predicted phase separation kinetics is presented.     

Structure development of PMMA/SAN blends in shear flow

Structure development of PMMA/SAN blends in shear flow is studied experimentally using optical microscopy and small-angle light scattering (SALS). The presence of flow promotes highly anisotropic structures, and the objective of this work is to obtain a relation between these anisotropic scattering patterns and the morphology. The aim is to understand the influence of flow on morphology development, by resolving the length scales of the domains parallel and perpendicular to the direction of flow. The diffuse-interface model, based on the Cahn–Hilliard theory, is used to predict the morphology as a function of shear by systematically increasing the shear rate. Special precautions are taken to avoid wall effects, demonstrating the importance of sheared periodic boundary conditions.     

Influence of blend composition on the mechanical properties and morphology of PC/ASA/SAN ternary blends

Bisphenol A polycarbonate/acrylonitrile–styrene–acrylic/styrene–acrylonitrile copolymer (PC/ASA/SAN) ternary blends were prepared over a range of compositions via mixing PC, SAN, and ASA copolymer by melt blending. An analysis was made on the mechanical properties and morphology of the blends. Special care was taken to make comparisons of the morphologies and properties of blends with different SAN content. When a small amount SAN was introduced to PC/ASA blends, the dispersion condition of ASA in the matrix was improved and a better integrated mechanical properties was realized. Further increasing the SAN content led to a decrease of impact strength, which was due to the changing of the morphology of the blends and the inherent brittleness of matrix. The study about the effect of ASA content on the properties of PC/ASA/SAN blends showed that the blend with 20 wt% ASA had good mechanical properties.     

Enhanced compatibility of SAN and PC in their blends exposed to extremely high shear field

Originally incompatible blends of SAN 30% and PC 70% were extruded with extremely high shear rate up to 10⁷ s⁻¹ as a typical example of the blends. The materials were examined with a scanning electron microscope (SEM), a pulsed NMR, etc. The molecular weight of the blends was also measured with gel permeation chromatography. The blends are of binary systems microscopically in the first run of extruding, in which the minor constituent is present as small spherical particles in the major constituent. The apparent volume fraction of the spherical minor constituent estimated from the microscopic photographs decreases with the shear rate. The fraction is decreased also with the repeated runs. SEM observation reveals that dimple fracture of microsize takes place on SAN sphere dispersed in PC matrix. And at the bottom of the dimple, a small particle, which would be composed of PC, is present. From these, SAN in the blend is thought to be partly ductile even at the temperature of liquid nitrogen. At the fifth run, the blend appears uniform or structureless. Dynamic loss tangent gives two peaks corresponding to that of SAN and that possibly attributed to PC. The latter shifts to lower temperatures with the number of extruding run. These show that some of SAN is mixed with PC in a compatible form. The pulsed NMR analysis supports the conclusion. Furthermore, the analysis suggests that some of SAN is mixed in PC. This result shows the compatibility of SAN with PC is enhanced in extremely high shear rate processing.     

Amphiphilic block copolymers of PtBA‐b‐PMMA as compatibilizers for blends of PET and PMMA

PET and PMMA were blended at various weight fractions. These blends were compatibilized by employing amphiphilic block copolymers of PtBA‐b‐PMMA, having three compositions (1:3, 1:1, 3:1) and three weight fractions (3, 5, and 7 wt%) using a co‐rotating twin screw extruder. The blends were evaluated for their mechanical, rheological, and morphological properties. Overall, the compatiblized blends showed improvement in properties compared with the properties of noncompatiblized blends. Mechanical properties of the compatibilized blends improved with an increase in the PMMA and compatibilizer weight fractions. It was observed that the compatibilizer with lower molecular weight and lower glass transition temperature, typically at 5 wt%, provided the overall best properties. POLYM. ENG. SCI. 46:1147–1152, 2006. © 2006 Society of Plastics Engineers.     

On the compatibility of polysaccharide/maleic copolymer blends. II. Thermal behavior of pullulan‐containing blends

The compatibility of pullulan with maleic acid/vinyl acetate copolymers in the solid state in the form of thin films was studied with thermogravimetry, differential scanning calorimetry, infrared spectroscopy, and optical microscopy. With respect to morphology, blends with a content of pullulan greater than 85 wt % exhibited an even distribution of finely dispersed particles. The thermal properties were dependent on the mixing ratio, and the interactions between components were quite pronounced in the pullulan‐rich blends. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1782–1791, 2002     

Effect of block copolymer containing ionic liquid moiety on interfacial polarization in PLA/PCL blends

Compared with poly(?‐caprolactone)‐b‐poly(ethylene glycol) block copolymer (BC), a systematic study of the effect of the concentration of the compatibilizer, poly(?‐caprolactone)‐b‐poly(ethylene glycol) BC containing ionic liquid moiety (BCIL), on the interfacial properties of a phase separating blend of poly(l ‐lactic acid)/poly(?‐caprolactone) (PLA/PCL) was performed. BCIL copolymer as a compatibilizer for immiscible PLA/PCL blend can reinforce the interactions between the two polymeric phases by the IL electrostatic interaction at interphase, and the particle size of PCL decreases because of interfacial reinforced‐compatibilization of IL moiety. Ion mobility of IL moiety at interphase and PCL phase for PLA/PCL/BCIL blend can induce interfacial blocking of charge carriers, and IL moiety segregating mainly at the interface can decrease the relaxation rate and increase the dielectric strength of interfacial polarization. Our results provide a methodology to characterize and tune the morphology and blocking of charge carriers with the aim of tailoring the dielectric interfacial properties of blends. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46161.     

Effects of AN-contents and shear flow on the miscibility of PC/SAN blends

The miscibility of polycarbonate (PC) with styrene-co-acrylonitrile random copolymer (SAN) has been systematically investigated as functions of acrylonitrile content and shear flow. Various AN-contents ranged from 11 to 74 wt% and different simple shear flow values up to 90 s⁻¹ have been used to explore the effect of both material and proceeding parameters on the miscibility of PC and SAN blends. The finest phase dispersion of the SAN particles was observed at AN=25 wt% for PC/SAN=70/30 blends under the same processing condition using scanning electron microscope (SEM). The obtained morphologies indicated that PC and SAN could form a partial miscibility blend and the maximum miscibility occurred at AN=25 wt%. This observation was supported by considering the shifts in the glass processes of the two rich phases of the blend using the dynamical mechanical analysis (DMA) measurements. The optimum interaction of the two components at AN=25 wt% calculated from ellipsometric technique was found to be the only responsible parameter for the high miscibility of the blend. The viscoelastic properties of the pure polymer components were found to play a minor role in the obtained morphologies. The effect of simple shear flow on the morphology of PC/SAN-25=70/30 blend has been also investigated using a special shear apparatus of parallel plate geometry. It has been found that the dispersed phase of SAN was elongated and broken-up in the direction of flow with weaker contrast at high shear rates. The shear rate was found to enhance the miscibility of SAN (dispersed phase) in the PC matrix to a great extent as seen in the weak contrast of the two phases observed by transmission electron microscope (TEM).     

Crystallinity and mechanical properties of polylactide/ether‐amide copolymer blends

The present study focuses on the improvement of impact properties and particularly on the interaction between crystallinity development and mechanical properties of impact modified polylactide (PLA). The PLA was toughened by the addition of a random linear ether‐amide copolymer (PEBAX 3533?). A random copolymer of ethylene, methyl‐acrylate, and glycidyl‐methacrylate (LOTADER AX8900?) was also used to reactively compatibilize the ether‐amide copolymer with the PLA matrix. Melt rheology of the blends was investigated in small amplitude oscillatory shear and showed that the impact modifier could significantly influence the viscoelastic response of the material. The Izod impact resistance and tensile properties were measured using standard testing protocols. The blend morphology was also examined using scanning electron microscopy on cryofractured and microtomed surfaces, while the crystalline morphology was assessed by optical microscopy. A sub‐micron dispersion of the impact modifier was achieved in the presence of the reactive compatibilizer. Significantly improved impact strength was found with 10 wt % impact modifier. High crystallinity samples showed the highest impact strength with values reaching 68 kJ/m², hence a 20‐fold improvement with respect to the neat PLA. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44677.     

Triple-shape memory properties of thermoplastic polyurethane/olefin block copolymer/polycaprolactone blends

Thermoplastic polyurethane (TPU)/olefin block copolymer (OBC)/polycaprolactone (PCL) blends (70/20/10 and 50/30/20) were melt-blended to form the first environmental OBC-based triple-shape memory polymer blends. In this work, PCL with low crystalline temperature (switching phase), OBC with medium crystalline temperature (switching phase), and TPU with high crystalline temperature (fixed phase) could form an alternative triple-shape memory polymer (TSMP). Two compatibilizers, OBC-g-glycidyl methacrylate (OBC-g-GMA) and dicumyl peroxide, were confirmed to show a synergistic effect in enhancing the compatibility further through the morphological observation. Crystallinity of both OBC and PCL in the blends with or without modification decreased in comparison with that of pure resin. For dual-shape behaviors, the shape fixing ratio (R_f) and shape recovery ratio (R_r) were up to 96.3% and 91.2% for the GMA and peroxide-modified blends (50/30/20). The higher amount of TPU didn’t give higher recovery ratio, but instead slightly lower R_r due to the morphology difference. For triple-shape behaviors, both TPU/OBC/PCL blend compositions with or without GMA or peroxide modifications gave high R_f(C→B) values in the first fixing stage, but slightly lower values R_f(B→A) in the second fixing stage, especially for (70/20/10) case. On the other hand, a reverse trend was observed for two recovery stages. To enhance the R_f(B→A) in the second fixing stage, higher deformation temperatures were considered, and a measurable increment on R_f(B→A) was attained. Through this subtle adjustment on the temperature difference between high and low deformation temperatures, the theoretical multi-shape memory shape could be readily tailored to meet different applications.     

The study of morphology,thermal and thermo‐mechanical properties of compatibilized TPU/SAN blends

The compatibilizing efficiency of three different compatibilizers in thermoplastic polyurethane/styrene‐co‐acrylonitrile (TPU/SAN) blends was investigated after their incorporation via melt‐mixing. The compatibilizers studied were poly‐ε‐caprolactone (PCL), a mixture of polystyrene‐block‐polycaprolactone (PS‐b‐PCL) and polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA), and a mixture of polyisoprene‐block‐polycaprolactone (PI‐b‐PCL) and polybutadiene‐block‐poly(methyl methacrylate) (PB‐b‐PMMA). All compatibilizers were synthesized by living anionic polymerization. Investigations of thermal and thermo‐mechanical properties performed by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DTMA), respectively, were systematically classified into two groups, i.e. blends of TPU or SAN with 20 wt% of different compatibilizers (so‐called limit conditions) and TPU/SAN 25/75 blends with 5 wt% of different compatibilizers. In order to determine the compatibilizer's location, morphology of TPU/SAN 25/75 blends was studied with transmission electron microscopy (TEM). Different compatibilization activity was found for different systems. Blends compatibilized with PCL showed superior properties over the other blends. Polym. Eng. Sci. 44:838–852, 2004. © 2004 Society of Plastics Engineers.     

Thermal conductivities of blends of polyethylene/SEBS block copolymer and polystyrene/SEBS block copolymer

Thermal conductivities of two series of blends of polystyrene and styrene–ethylene/butyrene–styrene block copolymer (PS/SEBS), and polyethylene and styrene-ethylene/butylene-styrene block copolymer (PE/SEBS) were measured. Here the PS part and hydrogenated polybutadiene (EB; ethylene-butene-1 copolymer) part of SEBS were confirmed to be miscible in PS and PE homopolymers, respectively, by the differential scanning calorimetry. The thermal conductivity of PS/SEBS increased, while that of PE/SEBS blends decreased monotonically, with increasing SEBS content. No significant changes in the range where microphases usually occur were noted. The thermal conductivities of PS/SEBS and PE/SEBS were explained by modifications of our equation for composites. Thermal conductivity of EB in SEBS was estimated from that of PS/SEBS blend as 4.9 × 10^?4 cal/s cm °C. Further, the thermal conductivity of PE/SEBS could be predicted by substituting the obtained value of EB into the modified equation. Therefore, the modified equations were confirmed to be applicable to thermal conductivities of PE/SEBS and PE/SEBS blends. © 1993 John Wiley & Sons, Inc.     

Effects of ABS‐g‐MAH on mechanical properties and compatibility of ABS/PC alloy

The effects of a compatibilizer, namely, an acrylonitrile–butadiene–styrene copolymer (ABS) grafted with maleic anhydrade (MAH) (ABS‐g‐MAH), on the mechanical properties and morphology of an ABS/polycarbonate (PC) alloy were studied The results showed that a small quantity of ABS‐g‐MAH has a very good influence on the notched Izod impact strength of the ABS/PC alloy without compromising other properties such as the tensile strength, flexural strength, and Vicat softening temperature (VST). The impact strength of the ABS/PC alloy, to a great extent, depends on the loading of ABS‐g‐MAH and the degree of grafting (DG) of MAH in the ABS‐g‐MAH. DSC analysis and SEM observation confirmed that ABS‐g‐MAH could significantly improve the compatibility of the ABS/PC alloy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 831–836, 2001