Morphology,dynamic mechanical,and electrical properties of bio‐based poly(trimethylene terephthalate) blends,part 1: Poly(trimethylene terephthalate)/poly(ether esteramide)/polyethylene glycol 400 bis(2‐ethylhexanoate) blends

Bio‐based PTT and PTT blends with PEEA of two different ion contents (275 ppm Na and 3515 ppm Na) and PEG 400 bis (2‐ethylhexanoate) were prepared by melt processing. The blends were characterized by differential scanning calorimetry, dynamic mechanical analysis, transmission electron microscopy, and atomic force microscopy. Electro‐static performance was also investigated for those PTT blends since PEEA is known as an ion conductive polymer. Here we confirmed that PEG 400 bis (2‐ethylhexanoate) improves the static decay performance of PTT/PEEA blends. DMA strongly suggests that PEG 400 bis (2‐ethylhexanoate) and PEEA are miscible pairs, and PEG 400 bis (2‐ethylhexanoate) selectively goes into the PEEA phase rather than the PTT phase, which lowers the T_g of PEEA. Besides topographic analysis of morphology and phase separation, tunneling atomic force microscopy was also applied to see if we can observe the surface directly for the static dissipative material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Crystallization,morphology, and electrical properties of bio‐based poly(trimethylene terephthalate)/poly(ether esteramide)/ionomer blends

Bio‐based poly(trimethylene terephthalate) (PTT) and poly(ether esteramide) (PEEA) blends were prepared by melt processing with varying weight ratios (0–20 wt %) of ionomers such as lithium‐neutralized poly(ethylene‐co‐methacrylic acid) copolymer (EMAA‐Li) and sodium‐neutralized poly(ethylene‐co‐methacrylic acid) copolymer (EMAA‐Na). The blends were characterized by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), polarized light microscopy (PLM), and transmission electron microscopy (TEM). DSC and PLM results showed that EMAA‐Na increased the crystallization rate for PTT significantly, whereas EMAA‐Li did not enhance the crystallization rate at all. Specific interactions between PEEA and ionomers were confirmed by DSC and TEM. Electrostatic performance was also investigated for those PTT blends because PEEA is known as an ion‐conductive polymer. Here, we confirmed that both sodium and lithium ionomers work as a synergist to enhance the static decay performance of PTT/PEEA blends. Morphological study of these ternary blends systems was conducted by TEM. Dispersed ionomer domains were encapsulated by PEEA, which increases the interfacial surface area between PEEA and the PTT matrix. This encapsulation effect explains the unexpected synergy for the static dissipation performance on addition of ionomers to PTT/PEEA blends. This core–shell morphology can be predicted by calculating spreading coefficient for the ternary blends. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Miscibility and crystallization kinetics of poly(trimethylene terephthalate)/amorphous poly(ethylene terephthalate) blends

The miscibility and crystallization kinetics of the blends of poly(trimethylene terephthalate) (PTT) and amorphous poly(ethylene terephthalate) (aPET) have been investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). It was found that PTT/aPET blends were miscible in the melt. Thus, the single glass transition temperature (T_g) of the blends within the whole composition range and the retardation of crystallization kinetics of PTT in blends suggested that PTT and aPET were totally miscible. The nucleation density of PTT spherulites, the spherulitic growth, and overall crystallization rates were depressed upon blending with aPET. The depression in nucleation density of PTT spherulites could be attributed to the equilibrium melting point depression, while the depression in the spherulitic growth and overall crystallization rates could be mainly attributed to the reduction of PTT chain mobility and dilution of PTT upon mixing with aPET. The underlying nucleation mechanism and growth geometry of PTT crystals were not affected by blending, from the results of Avrami analysis. POLYM. ENG. SCI., 47:2005–2011, 2007. © 2007 Society of Plastics Engineers     

Miscibility and melting behavior of poly(ethylene terephthalate)/poly(trimethylene terephthalate) blends

The miscibility and melting behavior of binary crystalline blends of poly(ethylene terephthalate) (PET)/poly(trimethylene terephthalate) (PTT) have been investigated with differential scanning calorimetry and scanning electron microscope. The blends exhibit a single composition‐dependent glass transition temperature (T_g) and the measured T_g fit well with the predicted T_g value by the Fox equation and Gordon‐Taylor equation. In addition to that, a single composition‐dependent cold crystallization temperature (T_cc) value can be observed and it decreases nearly linearly with the low T_g component, PTT, which can also be taken as a valid supportive evidence for miscibility. The SEM graphs showed complete homogeneity in the fractured surfaces of the quenched PET/PTT blends, which provided morphology evidence of a total miscibility of PET/PTT blend in amorphous state at all compositions. The polymer–polymer interaction parameter, χ₁₂, calculated from equilibrium melting temperature depression of the PET component was ?0.1634, revealing miscibility of PET/PTT blends in the melting state. The melting crystallization temperature (T_mc) of the blends decreased with an increase of the minor component and the 50/50 sample showed the lowest T_mc value, which is also related to its miscible nature in the melting state. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Crystallization and spherulitic growth kinetics of poly(trimethylene terephthalate)/polycarbonate blends

The macroscopic and microscopic melt‐crystallization kinetics of poly(trimethylene terphthalate) (PTT)/polycarbonate (PC) blends have been measured by differential scanning calorimetry (DSC), and optical microscopy (OM). The results are analyzed in terms of the Avrami equation and the Hoffman–Lauritzen crystallization theory (HL model). Blending with PC did not change the crystallization mechanism of PTT, but reduced the crystallization rate compared with that of neat PTT at the same crystallization temperature. The crystallization rate decreased with increasing crystallization temperature. The spherulitic morphology of PTT was influenced apparently by the crystallization temperature and by the addition of PC. X‐ray diffraction shows no change in the unit cell dimension of PTT was observed after blending. Through the HL theory, the classical regime II→III transition was detected for the neat PTT and the blends. The nucleation parameter (K_g), the fold‐surface free energy (σ_e), and the work of chain folding (q) were calculated. Blending with PC decreased all the aforementioned parameters compared with those of neat PTT. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Crystallization kinetics of poly(trimethylene terephthalate)/poly(ether imide) blends

The crystallization kinetics of a melt‐miscible blend, consisting of poly(trimethylene terephthalate) (PTT) and poly(ether imide) (PEI) prepared by solution precipitation, has been investigated by means of optical polarized microscopy and differential scanning calorimeter. It was found that both the PTT spherulitic growth rate (G) and overall crystallization rate constant (k_n) were depressed, with increasing PEI composition or crystallization temperature (T_c). The kinetic retardation was attributed to the decrease in PTT molecular mobility, and the dilution of PTT concentration due to the addition of PEI, which has a higher glass transition temperature (T_g). According to the Lauritzen–Hoffman theory of secondary nucleation, the crystallization of PTT in blends was similar to that of neat PTT as regime III, n = 4 and regime II, n = 2 growth processes, while the transition point of regime III to II has been shifted from 194°C for neat PTT to 190°C for blends. POLYM. ENG. SCI. 46:89–96, 2006. © 2005 Society of Plastics Engineers     

Calorimetric and dielectric study on poly(trimethylene terephthalate)/polycarbonate blends

Poly(trimethylene terephthalate) (PTT)/polycarbonate (PC) blends with different compositions were prepared by melt blending. The miscibility and phase behavior of melt-quenched and cold-crystallized blends were studied using differential scanning calorimetry (DSC) and dielectric relaxation spectroscopy. The blends of all compositions display only one glass transition (T _g ) in both states. The melting temperature and the crystallinity of PTT in the blend decrease with increasing PC content. The dielectric results for the melt-quenched blends, for PC content up to 60 wt.%, exhibited two merged relaxation peaks during the heating scan; the lower temperature relaxation peak represent the normal glass-transition (α) relaxation of the mixed amorphous phase and the higher temperature relaxation due to the new-constrained mixed amorphous phase after crystallization. Cold-crystallized blends displayed only one glass transition α-relaxation whose temperatures varied with composition in manner similar to that observed by DSC. The dielectric α-relaxation of cold crystallized blends has been analyzed. Parameters relating to relaxation broadening, dielectric relaxation strength, and activation energy were quantified and were found to be composition dependent. The PTT/PC blends could be considered as two-phase system, a crystalline PTT phase and a mixed amorphous phase consisting of a miscible mixture of the two polymers. However, the crystallinity was only detected for blends containing greater than 40 wt.% PTT.     

Thermal properties and non‐isothermal crystallization behavior of poly(trimethylene terephthalate)/poly(lactic acid) blends

Thermal properties and non‐isothermal melt‐crystallization behavior of poly(trimethylene terephthalate) (PTT)/poly(lactic acid) (PLA) blends were investigated using differential scanning calorimetry and thermogravimetric analysis. The blends exhibit single and composition‐dependent glass transition temperature, cold crystallization temperature (T_cc) and melt crystallization peak temperature (T_mc) over the entire composition range, implying miscibility between the PLA and PTT components. The T_cc values of PTT/PLA blends increase, while the T_mc values decrease with increasing PLA content, suggesting that the cold crystallization and melt crystallization of PTT are retarded by the addition of PLA. The modified Avrami model is satisfactory in describing the non‐isothermal melt crystallization of the blends, whereas the Ozawa method is not applicable to the blends. The estimated Avrami exponent of the PTT/PLA blends ranges from 3.25 to 4.11, implying that the non‐isothermal crystallization follows a spherulitic‐like crystal growth combined with a complicated growth form. The PTT/PLA blends generally exhibit inferior crystallization rate and superior activation energy compared to pure PTT at the same cooling rate. The greater the PLA content in the PTT/PLA blends, the lower the crystallization rate and the higher the activation energy. Moreover, the introduction of PTT into PLA leads to an increase in the thermal stability behavior of the resulting PTT/PLA blends. Copyright © 2011 Society of Chemical Industry     

Crystallization, hydrolytic degradation, and mechanical properties of poly (trimethylene terephthalate)/poly(lactic acid) blends

Crystallization, melting, hydrolytic degradation, and mechanical properties of poly(trimentylene terephthalate)/poly(lactic acid) (PTT/PLA) blends have been investigated. The blends show a single and composition-dependent glass-transition temperature (T _g) over the entire composition range, implying that these blends are fully miscible in the amorphous state. The observed T _g is found to increase with increasing PLA content and fitted well with the Gordon–Taylor equation, with the fitting parameter k being 0.91. The cold-crystallization peak temperature increases, while the melt-crystallization peak decreases with increasing the PLA content. Both the pure PTT and PTT/PLA blends cannot accomplish the crystallization during the cooling procedure and the recrystallization occurs again on the second heating. Therefore, on the thermogram recorded, there is exothermal peak followed by endothermal peak with a shoulder. However, to pure PLA, no crystallization takes place during cooling from the melt, therefore, no melting endothermic peak is found on the second heating curve. WAXD analysis indicates PLA and PTT components do not co-crystallize and the crystalline phase of the blends is that of their enriched pure component. With increasing PLA content, the hydrolytic degradation of the blend films increases, while both the tensile strength and the elongation at break of the blend films decrease. That is to say, the hydrolytic degradation of the PTT/PLA blends increases with the introduction of PLA at the cost of the decrease of the flexibility of PTT.     

Microstructure morphology of poly(trimethylene terephthalate)/amorphous poly(ethylene terephthalate) blends studied via small angle X‐ray scattering

The microstructure morphology of the poly(trimethylene terephthalate) (PTT) and amorphous poly(ethylene terephthalate) (aPET) blends prepared by solution precipitation has been investigated by means of optical polarized microscopy (POM) and small angle X‐ray scattering (SAXS). From the observation of POM, it was suggested that aPET was predominantly segregated into the interlamellar and/or interfibrillar regions upon PTT crystallization with the evidence that the PTT spherulitic morphologies of blends were volume filling. From results of SAXS data analysis, the maximum scattering peak (q_max) of Lorentz‐corrected SAXS profiles, amorphous layer thickness (l_a) and lamellar volume stacking fraction (?_s), the segregation morphology of PTT/aPET blends is characterized to be the interlamellar segregation morphology when the weight friction of aPET (w_aPET) ≤ 0.2 and the interlamellar and interfibrillar segregation coexisted when w_aPET > 0.2. The extent of aPET segregation was promoted by increasing aPET composition. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Miscible blends of poly(4‐vinyl phenol)/poly (trimethylene terephthalate)

A new miscible blend of all compositions comprising poly(4‐vinyl phenol) (PVPh) and poly(trimethylene terephthalate) (PTT) was discovered and reported. The blends exhibit a single composition‐dependent glass transition and homogeneous phase morphology, with no lower critical solution temperature (LCST) behavior upon heating to high temperatures. Interactions and spherulite growth kinetics in the blends were also investigated. The Flory–Huggins interaction parameter (χ₁₂) and interaction energy density (B) obtained from analysis of melting point depression are negative (χ₁₂ = ?0.74 and B = ?32.49 J cm^?3), proving that the PVPh/PTT blends are miscible over a wide temperature range from ambient up to high temperatures in the melt state. FTIR studies showed evidence of hydrogen‐bonding interactions between the two polymers. The miscibility of PVPh with PTT also resulted in a reduction in spherulite growth rate of PTT in the miscible blend. The Lauritzen–Hoffman model was used to analyze the spherulite growth kinetics, which showed a lower fold‐surface free energy (σ_e) of the blends than that of the neat PTT. The decrease in the fold‐surface free energy has been attributed to disruption of the PTT lamellae exerted by PVPh in an intimately interacted miscible state. Copyright © 2004 Society of Chemical Industry     

Crystallization behavior and morphology of double crystalline poly(trimethylene terephthalate)/poly(ethylene oxide terephthalate) copolymers

Double crystalline poly(trimethylene terephthalate)/poly(ethylene oxide terephthalate) copolymers (PTT/PEOT), with PTT content ranging from 16.5 to 65.5 wt%, were synthesized by melt copolycondensation. The morphological transformation of samples from microphase separation to macrophase separation was investigated by gel permeation chromatography and transmission electron microscopy. Differential scanning calorimetry and in situ wide‐angle X‐ray diffraction suggested that all copolycondensation samples displayed double crystalline behavior. The melt‐crystallization peak temperatures (T_{m, c} values) of PTT chains monotonously increased with increasing PTT content and were higher than that of homo‐PTT when the content of PTT was above 30.6 wt%. Interestingly, T_{m, c} values of PEOT chains were also increased with increasing PTT content. Polarized optical microscopy revealed that all copolycondensation samples studied could form ring‐banded spherulites and band spacing increased with increasing T_c values. In addition, band spacing decreased with increasing PTT content at a given T_c. Strangely, although PEOT was the main component in all copolycondensation samples, spherulitic morphology formed by the advance crystallization of PTT did not change after PEOT crystallization. Only a subtle change of quadrant tones was detected. © 2012 Society of Chemical Industry     

Structure,nonisothermal crystallization behavior,and thermal property study of poly(trimethylene terephthalate)/cellulose acetate butyrate blends

Poly(trimethylene terephthalate) (PTT)/cellulose acetate butyrate (CAB) blends were prepared by melting blending through a co‐rotating twin screw extruder. The structures of PTT/CAB blends were characterized by scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectra, and the results showed that CAB phase dispersed homogeneously in the PTT matrix and there existed evident phase interface between PTT and CAB. The nonisothermal crystallization behavior was investigated by differential scanning calorimetry (DSC) and was described with modified Avrami equation of Jeziorny and Mo equation, respectively. The results indicated that the half crystallization time (t_{1/ 2}) is much shorter, the nonisothermal crystallization kinetic rate constant (Z_c) is bigger at a given cooling rate, the cooling rate [F_z(T)] is smaller at a given relative crystallinity (X _t) of PTT/CAB blends than those of PTT, which proved that the addition of CAB improved the crystallization of PTT and made PTT crystallize more perfect and faster than pure PTT. In addition, thermogravimetric analysis (TGA) curves of PTT and PTT/CAB blends showed that effects of CAB content on the thermal decomposition of PTT/CAB blends were little. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Properties of poly(ethylene terephthalate)/poly(ethylene naphthalate) blends

Blends composed of poly(ethylene terephthalate) (PET) as the majority component and poly(ethylene naphthalate)(PEN) as the minority component were melt-mixed in a single screw extruder at various PET/PEN compound ratios. Tensile and flexural test results reveal a good PET/PEN composition dependence, indicating that the compatibility of the blends is effective in a macrodomain. In thermal tests, single transitions for T_g, T_m and T_c (crystallization temperature), respectively, are observed from DSC as well as single T_g from DMA except for 50/50 blends. These results suggests that the compatibility is sufficient down to the submicron level. Moreover, isothermal DSC tests along with Avrami analysis indicate that PET's crystallization is significantly retarded when blended with PEN. Results in this study demonstrate that PEN is a highly promising additive to improve PET's spinnability at high speeds.     

Thermal behavior,morphology, and some melt properties of blends of polycarbonate with poly(styrene-co-acrylonitrile) and poly(acrylonitrile-butadiene-styrene)

Blends of bisphenol-A polycarbonate (PC) with poly- (styrene-co-acrylonitrile) (SAN) and poly (acrylonitrile-butadiene-styrene) (ABS) prepared by screw extrusion and solution-casting were investigated by differential scanning calorimetry and scanning electron microscopy. From the measured glass-transition temperatures (T_g) and specific heat increments (ΔC_p) at the T_g, SAN appears to dissolve more in the PC-rich phase than does PC in the SAN-rich phase. Also, the decrease of T_g (PC) in PC/ABS blends is larger than in the PC/SAN blends. From the T_g behavior and the electron microscopy study, it is suggested that the compatibility increases more in the SAN-rich compositions than in the PC-rich compositions of the blends. In the study of extrudate swell of the PC/SAN blends and the PC/ABS blends, the maximum level of extrudate swell is reached at 0.5 weight fraction of PC for both blend systems. The Flory-Huggins polymer-polymer interaction parameter (χ12) between PC and SAN was calculated and found to be 0.034 ± 0.004. A similar value of χ for PC and SAN was found with the PC/ABS blends.     

Lamellar morphology of poly(trimethylene terephthalate)/poly(ether imide) blends studied via small‐angle X‐ray scattering

The lamellar morphology of a melt‐miscible blend consisting of poly(trimethylene terephthalate) (PTT) and poly(ether imide) (PEI) prepared by solution precipitation has been investigated by means of optical polarized microscopy (POM) and small angle X‐ray scattering (SAXS). From the observation under POM, it was suggested that PEI was predominantly segregated into the interlamellar and/or interfibrillar regions upon PTT crystallization since the PTT spherulitic morphologies of blends were volume‐filling. From results of SAXS data analysis, a larger amorphous layer thickness was identified in the blends, showing that some PEI was incorporated inside the interlamellar regions after crystallization. Despite the swelling of the amorphous layer, the amorphous layer thickness was relatively independent of the blend composition. It was concluded that amorphous PEI was located in the interlamellar regions of PTT as the weight fraction of PEI (w_PEI) [≤] 0.1, while amorphous PEI was predominantly segregated into the interfibrillar regions of PTT as w_PEI > 0.1, and the extent of interfibrillar segregation increased with increasing w_PEI. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Miscibility of poly(ether imide)/poly(ethylene terephthalate) blends

Summary Miscibility of blends of poly(ether imide) (PEI) and poly(ethylene terephthalate) (PET) were studied by differential scanning calorimetry (DSC). Single and composition-dependent T_g's are observed over the entire composition range, indicating that the blends are miscible in the amorphous region. The overall crystallization rate of PET in the blends decreased with increasing the PEI content. The interaction energy density B, which was calculated from the melting point depression of the blends using Nishi-Wang equation, was-5.5 cal/cm³.     

Crystallization of poly(ethylene terephthalate)/polycarbonate blends. I. Unreinforced systems

The crystallization and transition temperatures of poly(ethylene terephthalate) (PET) in blends with polycarbonate (PC) is considered using thermal analysis. Additives typically used in commercial polyester blends, transesterification inhibitor and antioxidant, are found to enhance the crystallization rate of PET. Differential scanning calorimetry (DSC) reveals two glass transition temperatures in PET/PC blends, consistent with an immiscible blend. Optical microscopy observations are also consistent with an immiscible blend. Small shifts observed in the T_g of each component may be due to interactions between the phases. The degree of crystallinity of PET in PET/PC blends is significantly depressed for high PC contents. Also, in blends with PC content greater than 60 wt %, two distinct crystallization exotherms are observed in dynamic crystallization from the melt. The isothermal crystallization kinetics of PET, PET modified with blend additives, and PET in PET/PC blends have been evaluated using DSC and the data analyzed using the Avrami model. The crystallization of PET in these systems is found to deviate from the Avrami prediction in the later stages of crystallization. Isothermal crystallization data are found to superimpose when plotted as a function of time divided by crystallization half-time. A weighted series Avrami model is found to describe the crystallization of PET and PET/PC blends during all stages of crystallization. © 1996 John Wiley & Sons, Inc.     

Antistatic performance and morphological observation of ternary blends of poly(ethylene terephthalate), poly(ether esteramide), and ionomers

Blends of poly(ethylene terephthalate) (PET) and poly (ether esteramide) (PEEA), which is known as an ion conductive polymer, were prepared by melt mixing using a twin screw extruder. Antistatic performance of the molded plaques and the effects of adding ionomers such as lithium neutralized poly(ethylene‐co‐methacrylic acid) copolymer(E/MAA‐Li), magnesium neutralized poly(ethylene‐co‐methacrylic acid) copolymer(E/MAA‐Mg), and zinc neutralized poly(ethylene‐co‐methacrylic acid) copolymer (E/MAA‐Zn) were investigated. Antistatic effect of adding poly(ethylene‐co‐methacrylic acid) copolymer(E/MAA) and polystyrene, and poly(ethylene naphthalate) (PEN) into PET/PEEA blends were also investigated. Here we confirmed that lithium ionomer worked the most effectively in those blend systems. We also confirmed that E/MAA worked to enhance the antistatic performance of PET/PEEA blends. Morphological study of these ternary blends system was conducted by TEM. Specific interaction between PEEA and E/MAA‐Li, and E/MAA were observed. Those ionomers and copolymer domains were encapsulated by PEEA, which could increase the surface area of PEEA in PET matrix. This encapsulation effect explains the unexpected synergy for the static dissipation performance on addition of ionomers and E/MAA to PET/PEEA blends. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Effect of blend ratio and elongation flow on the morphology and properties of epoxy resin‐poly(trimethylene terephthalate) blends

The effect of processing conditions on the morphology of polymer blends is a topic of tremendous practical interest especially for thermoset–thermoplastic blends. The effect of blend ratio and the nature of the flow field (shear flow vs. elongation flow) on the morphology is followed here using blends of diglycidyl ether of bisphenol A (DGEBA)‐poly(trimethylene terephthalate) (PTT). Morphology of the blends prepared by the conventional melt mixing technique is compared with that prepared by using an elongation mixer (RMX device invented by Muller et al.). The blends prepared by the elongation mixer showed excellent transparency and higher storage modulus at room temperature than the conventional mixer. In the case of samples prepared by the RMX device T_g of the epoxy phase has been shifted to lower temperatures indicating a molecular level mixing between PTT and DGEBA. However the conventional melt mixed samples showed only a marginal shift in T_g to low temperatures indicating that the system is not as miscible as that prepared by the RMX device. The use of RMX device for thermoset–thermoplastic blends is novel and no work has been reported in this relation. The properties of the blends were strongly affected by the composition and the crystallization of the semicrystalline PTT phase. POLYM. ENG. SCI., 55:1679–1688, 2015. © 2014 Society of Plastics Engineers