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Poly(trimethylene terephthalate)/ZnO nanocomposites were successfully prepared by dual in situ polymerization. Firstly, ZnO nanoparticles were synthesized by a simple polyol method using 1,3-propanediol (PDO) as solvent and stabilizer. Then, PTT/ZnO nanocomposites were prepared by in situ polymerization. The results of Fourier transform infrared spectra showed that PTT molecular chains were grafted to the surface of ZnO nanoparticles. The results of 1H NMR spectra confirmed that propyl ester molecules (as reaction product) were incorporated into PTT molecular chains. It was found that the intrinsic viscosity and molecular weight of synthesized PTT decreased with the addition of ZnO nanoparticles and the incorporation of propyl ester molecules. TEM results showed that ZnO nanoparticles with particle size of 20 ~ 30 nm were well dispersed and fully distributed in the polymer matrix. Besides, the melting temperatures and crystallization temperature decreased gradually and then increased slightly with the increasing loading of ZnO nanoparticles. Because of the strong interaction between ZnO nanoparticles and PTT matrix, the thermal stability of PTT/ZnO nanocomposites was improved. Interestingly, the results of Polarized Optical Microscopy showed that banded spherulites morphology can be observed in all PTT/ZnO nanocomposite samples. However, at higher loading of ZnO nanoparticles, band spacing became larger and was finally disturbed. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Poly(trimethylene terephthalate)/poly(propylene glycol) (PTT/PPG) segmented random copolymers were synthesized by melt copolycondensation. The weight fraction of PPG blocks was ranged from 12.1 to 33.4 wt%, which was confirmed by 1H NMR spectroscopy. The result of wide-angle X-ray diffractometer indicated that all copolymers had the same crystal structure of PTT homopolymer at room temperature. At a determined crystallization temperature, ring-banded spherulites could be observed in all copolymers samples, and the band spacing increased with the increase of PPG content. Morphologies of copolymers after nonisothermal crystallization process were strongly depended on the cooling rate. Well-defined ring-banded spherulites can be observed only at moderate cooling (20°C/min), while it was really hard to be observed at too low (2.5°C/min) or too high (by air-quenching) cooling rate. Moreover, the size of spherulites decreased with the increase of cooling rate. Finally, different nonisothermal crystallization kinetics were adopt to analyze this copolymer system, and only the Mo method was suitable to describe this copolymer system. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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 ( Tm, 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, Tm, 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 Tc values. In addition, band spacing decreased with increasing PTT content at a given Tc. 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 [ABSTRACT FROM AUTHOR]

The sol-gel technique has provided promising opportunities for the preparation of polymer/inorganic hybrid materials at the molecular level, which ensures the inorganic particles are well dispersed in the organic matrix. In this work, poly(trimethylene terephthalate) (PTT)/silica nanocomposites were fabricated via the sol-gel technique and in situ polymerization. Fourier transform infrared and nuclear magnetic resonance analyses confirmed that some PTT molecular chains were grafted to the surface of silica. Unlike pure PTT, the grafted PTT was insoluble in a mixed solvent of chloroform and hexafluoro-2-propanol. Both transmission electron microscopy and scanning electron microscopy showed that the silica particles, with a size of 40-50 nm, were homogeneously dispersed in the PTT matrix with no preferential accumulation in any region. Differential scanning calorimetry revealed that the glass transition temperature and cold-crystallization peak of the composites gradually increased with increasing silica loading. A simultaneous increase of stiffness and toughness was observed for the nanocomposites. Moreover, polarized optical microscopy showed that the nanocomposites exhibited interesting banded spherulites, which were different from banded spherulites of PTT previously reported. The nanocomposites with covalent bonding between silica and PTT gave a series of interesting results, such as elevated glass transition temperature, simultaneous increase of stiffness and toughness as well as surprising banded spherulites. Copyright © 2009 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

This article discusses a study which examined the melting behavior and crystallization kinetics of poly(trimethylene terephthalate) (PTT)/stainless steel fiber (SSF) composites. The study used differential scanning calorimetry and polarized optical microscopy to investigate the morphology of the composites. It showed increased crystallization temperature to the matrix. It also found lower activation energies of the composites than that of pure PTT.

The effects of added maleated thermoplastic elastomer (TPEg) on rheological properties and morphologies of polypropylene (PP)/polyamide-6 (PA6) blends are examined. For comparison, non-maleated version (TPE) is also added to the above binary blends. The magnitude of complex viscosity and viscoelastic moduli of PP/ PA6/TPE blends gradually decrease with the content of TPE. However, for PP/PA6/TPEg blends, these above parameters increase dramatically with increasing content of reactive TPEg and shear-thinning behavior becomes more obvious. SEM micrographs show that the addition of TPEg effectively increases compatibility between PP and PA6 and results in a considerable decrease in the domain size of dispersed phase; whereas the ternary blends containing non-reactive TPE exhibit a typical characteristic of immiscible blends with a very coarse morphology. TEM results further reveal that for PP/PA6/TPEg blends, a core-shell structure consisting of PA6 particles encapsulated with POE are probably formed in PP matrix. [ABSTRACT FROM AUTHOR]

Abstract: Poly(trimethylene terephthalate)/polyethylene glycol (PTT/PEG) copolymers, with PEG content ranging from 27.2 to 47.4 wt%, were synthesized by melt copolycondensation. Wide-Angle X-ray diffractometer revealed that all copolymers had the same crystal structure of homo-PTT at room temperature. All copolymers could form ring-banded spherulites, and band spacing increased with increasing PEG content at a given crystallization temperature. Nonisothermal crystallization morphology of copolymers was greatly influenced by cooling rate. When the cooling rate was 2.5 °C/min or lower, banded patterns were absent, whereas when the cooling rate was 20 °C/min or higher, a novel crystal morphology composed of non-banded spherulites (central part) and ring-banded spherulites with decreasing band spacing along the radial growth direction was observed. Moreover, the size of the non-banded spherulitic part decreased with increasing cooling rate. Finally, the nonisothermal crystallization kinetics of copolymers were analyzed and only the Mo method was satisfactory to accurately describe this system. [Copyright &y& Elsevier]

Abstract: A series of poly(trimethylene terephthalate)/poly(ethylene oxide terephthalate) copolymers with approximately 25 wt% PEG content were synthesized and investigated. The results showed that the thermal stability of copolymers increased with increasing M n, PEG from 1000 to 4000 g/mol. However, the thermal stability of the copolymer with M n, PEG = 300 g/mol was better than the copolymer with M n, PEG = 600 g/mol. The nonisothermal crystallization kinetics of the copolymers was analyzed using Ozawa and Mo models, and only the Mo method was satisfactory in describing this system. Polarized optical microscopy revealed that all copolymers could form ring banded spherulites and the temperature window for their formation was basically identical for all copolymers. In addition, the spherulitic growth rate curves of copolymers exhibited a bell shape, and both the maximum growth rate and the crystallization temperature corresponding to the maximum growth rate increased with the increase in M n, PEG. [Copyright &y& Elsevier]

PA6 blended with core-shell and grafted ABS was prepared by in situ reactive extrusion. In the extrusion and injection process, submicron-sized ABS droplets were evenly dispersed in core-shell ABS/PA6 blends, resulting in higher impact strength. However, the morphology of grafted ABS/PA6 blends transformed to agglomeration from uniform distribution. • PA6 blends with core-shell and grafted ABS was prepared by in situ reactive extrusion. • Different ABS resulted in the evolution of morphology in extruded / injected process. • The toughening effect of core-shell ABS is higher than that of grafted ABS. The focus was the investigation of the morphology and properties of PA6 blends with core-shell and grafted ABS by in-situ reactive extrusion. The compatibility and morphology of ABS/PA6 compatibilized blend can be controlled by ABS type and blend composition. The morphology results illustrated that submicron-sized ABS droplets were evenly dispersed in core-shell ABS/PA6 blends, resulting in a significant improvement in the impact strength. Aggregation of submicron-sized ABS particles was observed in grafted ABS/PA6 blends, corresponding to lower toughness. Due to having higher contents of the rigid component, the grafted reactive blends presented higher tensile and flexural strengths. This result indicated that the toughening effectiveness of reactive blends was determined by the structure variables of ABS. [ABSTRACT FROM AUTHOR]