Application of styrene‐acrylonitrile random copolymer–polyarylate block copolymer as reactive compatibilizer for polyamide and acrylonitrile‐butadiene‐styrene blends

Styrene‐acrylonitrile random copolymer (SAN) and polyarylate (PAr) block copolymer were applied as a reactive compatibilizer for polyamide‐6 (PA‐6)/acrylonitrile‐butadiene‐styrene (ABS) copolymer blends. The SAN–PAr block copolymer was found to be effective for compatibilization of PA‐6/ABS blends. With the addition of 3.0–5.0 wt % SAN–PAr block copolymer, the ABS‐rich phase could be reduced to a smaller size than 1.0 μm in the 70/30 and 50/50 PA‐6/ABS blends, although it was several microns in the uncompatibilized blends. As a result, for the blends compatibilized with 3–5 wt % block copolymer the impact energy absorption reached the super toughness region in the 70/30 and 50/50 PA‐6/ABS compositions. The compatibilization mechanism of PA‐6/ABS by the SAN–PAr block copolymer was investigated by tetrahydrofuran extraction of the SAN–PAr block copolymer/PA‐6 blends and the model reactions between the block copolymer and low molecular weight compounds. The results of these experiments indicated that the SAN–PAr block copolymer reacted with the PA‐6 during the melt mixing process via an in situ transreaction between the ester units in the PAr chain and the terminal amine in the PA‐6. As a result, SAN–PAr/PA‐6 block copolymers were generated during the melt mixing process. The SAN–PAr block copolymer was supposed to compatibilize the PA‐6 and ABS blend by anchoring the PAr/PA‐6 and SAN chains to the PA‐6 and ABS phases, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2300–2313, 2002     

Properties of a thermotropic liquid crystalline polymer blended with different thermoplastics

Thermal, rheological, morphological, and mechanical properties of a thermotropic liquid crystalline polymer, TLCP (copolyester Vectra A-950 from Hoechst), blended with a polycarbonate (PC), a polyethylene glycol terephthalate (PETG), and a blend of PC and PETG (20/80) are presented and discussed. Important supercooling effects are observed for the TLCP. For the blends the glass transition temperature of the matrix is shown to decrease slightly, suggesting partial miscibility of the components. A finer dispersion is observed for the TLCP/PC blends, at least for TLCP concentrations lower than 20%, for which the mechanical properties are quite good. For higher TLCP concentrations, as well as for the other two matrices, the mechanical properties follow more or less the mixing rule, and the morphology of the blends suggests poor adhesion. We were unable to obtain fibrillar structures by extruding the blends through a capillary rheometer; in the TLCP/PC blends, the TLCP domains were too small, and for the other blends the extrudates had not enough melt strength.     

Study on the kinetics of transesterification reaction between poly(ethylene terephthalate) and its copolyesters

Polyethylene terephthalate (PET) was blended with two kinds of co[poly(ethylene terephthalate-p-oxybenzoate)] (POB–PET) copolyester, designated as P46 and P64, respectively. The PET and POB–PET copolyester were combined in the ratios of 85/15, 70/30, and 50/50. The blends were melt mixed in a Brabender Plasticorder at 275, 285, and 293°C for different amounts of time. The transesterification reactions during the melt mixing processes of PET with POB–PET copolyester blends were detected by proton nuclear magnetic resonance analysis. The values of the rate constants are a function of temperature and the composition of blends. The transesterification reactions that may occur during the melt mixing processes have been discussed also. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2727–2732, 1999     

3D printability of highly ductile poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate)-EMAA blends

In this work, ionomers were employed to improve the adhesion between 3D printed layers of poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG), a commonly used polymer in 3D printing. The printability, rheology, and mechanical properties of PETG were tailored by incorporating poly(ethylene-co-methacrylic acid) neutralized with sodium (EMAA), a soft ionomer. PETG/EMAA polymer blends were prepared by melt extrusion to yield filaments for 3D fused filament fabrication (FFF) printing in different compositions by weight: 70/30, 50/50, and 30/70. The filaments and 3D printed samples were characterized by scanning electron microscopy, rheological and tensile tests. The results revealed that the interaction between PETG and EMAA favored the production of 3D printed samples with enhanced adhesion of layers, ductility, and toughness compared to neat PETG. Increases of 83.5 times in toughness and 86.4 times in ductility were achieved. The blends 30/70 and 50/50 presented the best printability in terms of adhesion between printed layers and mechanical properties.     

Self-healing polymer blend based on PETG and EMAA

In this work, novel immiscible polymer blends with remarkable self-healing properties were developed. The blends are based on poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG), a nonself-healing polymer, and the ionomer sodium-neutralized poly(ethylene-co-methacrylic acid) (EMAA), with self-healing abilities. The ratios of (PETG)/ (EMAA) was varied from 0 to 100% (w/w) and mixtures were prepared using a twin-screw melt extrusion. The blend studied compositions were characterized by scanning electron microscope, differential scanning calorimetry, dynamic mechanical analysis and self-repair tests. The results revealed that blends samples were able to self-repair damages created by Vickers microhardness indentations. The self-repair is presented through video records where the establishment of scars in the damaged area can be observed. For the composition 50/50 (w/w), the whole repair was observed due the synergic effect between polymer chain mobility, new chemical interactions promoted between PETG and EMAA, thus improving its self-healing ability.     

Study on the effect of dispersion phase morphology on porous structure of poly (lactic acid)/poly (ethylene terephthalate glycol-modified) blending foams

A methodology for blending foam of poly (lactic acid) (PLA)/poly (ethylene terephthalate glycol-modified) (PETG) was proposed. PLA/PETG blends were prepared through a melt blending method, using multiple functionality epoxide as reactive compatibilizer. The effects of blending ratio and compatibilizer content on the dispersion morphology, molecular structure, mechanical properties, and rheological behavior of PLA/PETG blends were studied. Then PLA/PETG blends were foamed using supercritical CO₂ as physical blowing agent, and their porous structure, pore size, as well as pore density were investigated. The results showed that the mechanical properties and rheological parameters such as melt strength and melt elasticity, as well as the porous structure of the foams dispersion morphology of PLA/PETG blends were affected strongly. The melt elasticity of PLA/PETG blends increased with increasing compatibilizer content. Dispersion phase morphology of PLA/PETG blends also had a significant effect on the pore density of all the samples. The results indicated that homogeneous and finer porous morphology of PLA/PETG foams with high expansion ratio could be achieved with a proper content of compatibilizer in the blends.     

Binary blends containing a commercial polyarylate

A commercial polyarylate (PAr), a copolyester of Bisphenol-A with 50 percent terephthalate-50 percent isophthalate, has been characterized by means of a combination of gel permeation chromatography and viscometry. It has been studied as first component of a series of polymer blends. The presence of either one glass transition temperature (T_g) or two has been used as a criterion to determine the miscibility of each blend. In some cases, the possible incidence of transesterification reactions has been considered.     

不同PETG对PS/PETG共混物相态结构的影响

采用转矩流变仪制备了聚苯乙烯/聚对苯二甲酸-乙二醇-1,4-环己烷二甲醇酯(PS/PETG)共混物和PS/改性PETG（PETG-M）共混物。采用旋转流变仪和熔体流动速率测定仪测定了PS、PETG和PETG-M的流变性能;采用扫描电子显微镜观测了共混物的相态结构。结果表明,随着PETG和PETG-M含量的提高,PS/PETG共混物和PS/PETG-M中PETG和PETG-M分散相颗粒平均粒径都增大,分散相颗粒密度都减小,在含量相同的情况下,PETG-M的分散相颗粒平均粒径小于PETG,PETG-M的分散相颗粒密度高于PETG,PETG-M的分散相粒径分布宽度更窄。     

Toughening of polyethylene terephthalate/amorphous copolyester blends with a maleated thermoplastic elastomer

The toughening of polyethylene terephthalate (PET)/amorphous copolyester (PETG) blends using a maleic anhydride grafted mixture (TPEg) of polyethylene‐octene elastomer and a semicrystalline polyolefin plastic (60/40 by weight) was examined. The TPEg was more effective in toughening PETG than PET, although the dispersion qualities of the TPEg particles in PET and PETG matrices were very similar. At the fixed TPEg content of 15 wt %, replacing partial PET by PETG resulted in a sharp brittle‐ductile transition when the PETG content exceeded the PET content. Before the transition, PET/PETG blends were not toughened with the TPEg of 15 wt %, whereas after the transition, the PET/PETG blends with 15 wt % of TPEg, similar to the PETG/TPEg (85/15) binary blend, maintained a super‐tough level. The impact‐fractured surfaces of the PET/PETG/TPEg blends were also evaluated. When PETG content was lower than PET content, the ternary blend showed a brittle feature in its impact‐fractured surface, similar to the PET/TPEg (85/15) binary blend. While PETG content exceeded PET content, however, the impact‐fractured surface of the ternary blend was very similar to that of PETG/TPEg (85/15) binary blend, exhibiting intensive cavitation and massive matrix shear yielding, which were believed to be responsible for the super‐tough level of the blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 797–805, 2003     

Preparation,morphology, and properties of multilamellar barrier materials based on blends of high‐density polyethylene and copolyester

The multilamellar barrier materials based on the blends of high‐density polyethylene (HDPE) and copolyester (PETG) were prepared via melt extrusion, and poly(ethylene‐co‐acrylic acid) (EAA) as a compatibilizer was incorporated into the blends. A systematic investigation was carried out, with regard to morphology and properties. Scanning electron microscopy observation displayed the laminar morphology for the blends with the whole compositions, and the thinner laminas of the PETG phase formed in the HDPE matrix by incorporating EAA into the blends. In addition, the number and the size of the laminas of the dispersed phases were also dependant on the die temperature and screw speed, respectively. Evaluation of the mechanical properties demonstrated that incorporation of the EAA resulted in an improvement of the mechanical properties. These behaviors are attributed mainly to better adhesion and compatibility between HDPE and PETG, which has been confirmed by thermal analysis and the rheological properties. On the basis of these premises, it is reasonable to suggest that the improved barrier properties of the ternary blends with increasing concentration of the EAA be attributed to both the increase in the number of the laminas of the PETG and the decrease in their thickness, which prohibits the organic solvent molecules from entering into and permeating through the amorphous regions of the blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3791–3799, 2006     

Effects of compatibilizer and testing speed on the mechanical and morphology behaviors of co‐continuous amorphous copolyester‐polyoxymethylene blends

Co‐continuous amorphous copolyester (PETG)/polyoxymethylene (POM) (50/50 wt%/wt%) blends were prepared using a twin screw extruder followed compression molding. Two types of thermoplastic polyurethane (TPU) (i.e., polyester‐based and polyether‐based) were used to compatibilize the blends system. The thermal properties were characterized by using differential scanning calorimetry (DSC). The mechanical properties of the co‐continuous PETG/POM blends were studies through flexural and single‐edge notch tensile test (SEN‐T). The SEN‐T test was performed at three different testing speeds; 1, 100, and 500 mm/min. Scanning electron microscope (SEM) was used to access the fracture surface morphology. The flexural strength of the PETG/POM blends was decreased in the presence of TPU. This was attributed to the elastomeric nature of the TPU. The compatibilizing effects of TPU on the PETG/POM blends were proven by moderate improvement in the fracture toughness and confirmed by the SEM observation. The SEN‐T fractured surface of the compatibilized blends showed gross matrix shear yielding as compared to the uncompatibilized system. The K_c values of the PETG/POM blends decreased as the testing speed increased. The optimum toughening effect was observed in PETG/POM blends compatibilized with polyether‐based TPU at testing speed of 100 mm/min. The polyether‐based TPU is a more efficient compatibilizer, because the amount required is one‐half that of the polyester‐based counterpart to achieve the same K_c value. This was attributed to the elastomeric nature of the polyether‐based TPU. The softer nature of polyether‐based TPU could provide better toughening effect than the polyester‐based TPU, which is relatively harder in nature. POLYM. ENG. SCI., 45:710–719, 2005. © 2005 Society of Plastics Engineers     

Thermal property and miscibility of polycarbonate/copolyester blends

Summary The thermal property and the miscibility of polycarbonate (PC)/copolyester blends were investigated. For the study, different copolyesters were synthesized from terephthalic acid (TPA) and various mixtures of ethylene glycol (EG) and cyclohexane dimethanol (CHDM). Various blends of PC and copolyester were prepared by melt mixing and thermal properties of the blends were studied employing differential scanning calorimeter. It was found that the blends of the PC and the copolyesters were partially miscible when the glycol in the copolyester was composed of 10, 20, or 30 mole % CHDM. However, the blends of the PC and the copolyesters were miscible in all proportions when the glycol in the copolyester was composed of 50 or 70 mole % CHDM. Miscibilities of the PC/copolyester blends depending on the composition of the copolyester are discussed based on the thermal properties of the blends.     

PPC-MA/PETG共混型生物降解材料的结构与性能研究

采用熔融共混法制备了马来酸酐(MA)封端聚碳酸亚丙酯(PPC)和聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯(PETG)的共混物(PPC-MA/PETG),采用套管上吹法将共混物吹塑成膜.通过差示扫描量热仪(DSC)、热失重分析(TGA)及扫描电子显微镜(SEM)等手段系统地研究了共混物的热、力学性能及形貌.结果表明:PPC-MA/PETG共混物为部分相容体系;MA封端PPC可以提高PPC的热分解温度(T-5%),PETG与PPC-MA共混进一步提高了PPC的热性能;当PETG含量低时,PETG作为岛相分散在PPC基体中,随着含量的增加,共混物将发生"海-岛"结构转变成"海-海"结构;共混物薄膜的力学性能较纯PPC大幅增强,从4.7MPa提高到16.93MPa.PPC-MA与PETG共混可以获得力学性能较好的膜材料,改善PPC材料的缺陷,在包装、生物医用材料等领域具有广阔的应用前景.     

Blends of poly(ethylene terephthalate) and a polyarylate before and after transesterification

Blends of poly(ethylene terephthalate) (PET) and a copolyester of bisphenol A–terephthaloylisophthaloyl (PAr) (2:1:1) have been studied both before and after transesterification. The physical blends exhibit phase separation in their amorphous states: a pure PET phase and a mixed PAr-rich phase. In spite of this phase separation, PET crystallinity in blends, normalized to PET fraction, surprisingly goes through a maximum at 25% PAr content. The transesterfied copolymers are noncrystallizable and exhibit a single T_g between those of starting polymers, PET and PAr.     

Blends of high temperature copolycarbonates with bisphenol-A-polycarbonate and a copolyester

The phase behavior of blends of copolycarbonates containing 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexanone (TMC-PC) and bisphenol-A repeat units with its constituent homopolymers was determined using melt mixing, solution casting, and precipitation casting methods. Miscibility was observed for all combinations except for some involving the TMC-PC homopolymer. Phase behavior was assessed using differential scanning calorimetry and visual assessment of optical clarity. The blending procedure was found to affect the phase behavior in some blends due to interchange reactions and casting methods. Based on the observations of the cast blends, the intramolecular interaction energy of the copolycarbonate was determined to be between 0.029 and 0.036 cal/cc. The phase behavior of these copolycarbonates and a copolyester based on 1,4-cyclohexanedimethanol with terephthalic and isophthalic acids was determined after melt mixing. The copolyester is miscible with all of the copolycarbonates, even in the absence of interchange reactions.     

Processing of thermotropic liquid crystalline polymers and their blends—analysis of an in-situ LCP composite system

Thermotropic LCP/LCP fiber blends were prepared by a combination of meltblending and hot-drawing, using a wholly aromatic copolyester KU-9211 (also called K161 from Bayer A.G.) and an aliphatic containing LCP (liquid crystalline polymer) PET/PHB60 (from Kodak Tennessee Eastman). Morphological evidence, including scanning electron (SEM) and transmission electron microscopy (TEM), showed that the dispersed phase consisted primarily of highly oriented, 0.5 to 2 μm diameter rigid-rods of aromatic fibers imbedded in a matrix of predominantly aliphatic LCP fibrils with diameters in the range of 20 to 50 nm. An interphase of approximately 50 nm strongly bonded the two phases together. The fiber blends were characterized using dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA), gas chromotography/mass spectroscopy (GC/MS), and rheological measurements. It appears that the processing conditions employed for melt blending had caused PET/PHB60 to undergo chain scission, thereby creating chemical interactions between the two LCP components during the melt blending process. Differential scanning calorimetry (DSC) thermograms as well as nuclear magnetic resonance (NMR) spectra of the extracted fraction from the mixture of 30 wt% K161/70 wt% PET(PHB60) confirmed the chemical interaction between the two thermotropic liquid crystalline polymers.     

Co[poly(ethylene terephthalate-p-oxybenzoate)] and its blends with poly(ethylene terephthalate): Transesterification reaction and fractured surface morphology

A series of co[poly(ethylene terephthalate-p-oxybenzoate)] copolyesters, viz., P28, P46, P64, and P82, were synthesized. These copolyesters were blended with poly(ethylene terephthalate) (PET) at the level of 10 wt % at 293°C for different times. The results from proton NMR analysis reveal that a significant amount of the transesterification has been detected in the cases of PET/P28, PET/P46, and PET/P64 blends. The blending time necessary before any transesterification reaction could be detected depends on the composition of copolyester, e.g., a time less than 3 min is needed for both PET/P28 and PET/P46 blends, while a longer time of 8–20 min is needed for the PET/P64 blend. It is concluded that the higher the mol ratio of the POB moiety in the copolyester is the longer the blending time needed to initiate the transesterification. The degree of transesterification is also increased as the duration of melt blending is prolonged. Two-phase morphology was observed by scanning electron microscopy (SEM) micrographs in all the blends. It was observed that the more similar the composition between the copolyester and PET in the blends is the better the miscibility or interfacial adhesion between the two phases. Moreover, the miscibility can be markedly improved by the duration of melt blending. © 1996 John Wiley & Sons, Inc.     

Property enhancement of poly(butylene succinate)/poly(ethyleneglycol-co-cyclohexane-1,4-dimethanolterephthalate) blends via high-speed extrusion and in situ fibrillation

In the current work, poly(butylene succinate)(PBS)/poly(ethylene glycol-co-cyclohexane-1,4-dimethanolterephthalate) (PETG) blends were first prepared by high-speed extrusion melt processing, and the dependence of the dispersed morphology(phase size) was investigated as function of screw speed. Then, the prepared blends were subjected to a “melt extrusion-uniaxial cold stretching” process to convert the dispersed phase into fibrillar structure, and the diameter change and property enhancement of PBS/PETG blends were further studied. It was found, at fixed ratio of PBS/PETG = 80/20 (wt/wt), the diameters of the PETG was changed from 2.25, 1.29, 1.11, 0.89 μm to 1.13, 0.64, 0.50, 0.38 μm, as increasing the screw speed from 150, 500, 700 rpm to 900 rpm, respectively. In addition, increasing the extrusion speed is favorable not only for smaller but more uniform dispersed phase particles, thus leading to finer microfibrils with narrower diameter distribution after cold stretching. As a result, the yield strength of PBS could be improved from 25.6 to 39.8 MPa for blend obtained via high-speed extrusion and stretching. Our work is important for the preparation of polymer blends with improved property. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47549.     

Studies on blends of binary crystalline polymers: Miscibility and crystallization behavior in PBT/PAr(I27-T73)

The miscibility and crystallization behavior of binary crystalline blends of poly(butylene terephthalate) [PBT] and polyarylate based on Bisphenol A and a 27/73 mole ratio of isophthalic and terephthalic acids [PAr(I27-T73)] have been investigated by differential scanning calorimetry (DSC). This blend system exhibits a single composition-dependent glass transition temperature over the entire composition range. The equilibrium melting point depression of PBT was observed, and Flory interaction parameter χ₁₂ = −0.96 was obtained. These indicate that the blends are thermodynamically miscible in the melt. The crystallization rate of PBT decreased as the amount of PAr(I27-T73) increased, and a contrary trend was found when PAr(I27-T73) crystallized with the increase of the amount of PBT. The addition of high-T_g PAr(I27-T73) would suppress the segmental mobility of PBT, while low-T_g PBT would have promotional effect on PAr(I27-T73). The crystallization rate and melting point of PBT were significantly influenced when the PAr(I27-T73) crystallites are previously formed. It is because not only does the amorphous phase composition shift to a richer PBT content after the crystallization of PAr(I27-T73), but also the PAr(I27-T73) crystal phase would constrain the crystallization of PBT. Thus, effects of the glass transition temperature, interaction between components, and previously formed crystallites of one component on the crystallization behavior of the other component were discussed and compared with blends of PBT and PAr(I-100) based on Bisphenol A and isophthalic acid.     

Permanently electrostatic dissipative (ESD) property via polymer blending: Rheology and ESD property of blends of PETG/ESD polymer

Rheological and electrical properties were studied on blends of a PETG polyester (cyclohexanedimethanol-modified polyethylene terephthalate) and an inherently static dissipative high molecular weight polyether based copolymer, hereafter referred to as ESD polymer. Several important electrical properties and flow phenomena have been observed. First of all, the PETG blends could result in ESD protected material with excellent performance and a minimal effect on physical properties and melt processability. The rheological characterization reveals that the ESD polymer has a high melt viscosity even at a temperature more than 150 degrees above its melting temperature and that it exhibits pseudoplastic behavior. The PETG melt shows a near constant dynamic viscosity at a low frequency region. The viscosity of the ESD polymer and PETG melt exhibits a cross over at the temperature range from 200–220°C; the PETG melt is the lower viscosity component at low shear rate and the ESD polymer is the lower viscosity component at high shear rate. This appears to result in the existence of a small composition difference in the thickness direction of an injection-molded ESD polymer/PETG part, with a greater fraction of the ESD polymer component in the skin section. This, in turn, could enhance the surface conductivity of the skin region of an injection-molded part. © 1993 John Wiley & Sons, Inc.