Crystallization Of PTT Research Articles

Prominent Crystallization Promotion Effect of Montmorillonite on PTT/PC Blends with PTT as the Continuous Phase.

To regulate the crystallization of poly(trimethylene terephthalate) (PTT) retarded by melt blending with polycarbonate (PC), the crystallization of the PTT/PC blend was investigated employing nano-montmorillonite (MMT) as a crystallization promoter with PTT as the continuous phase. The results showed that MMT exhibits a significant promoting effect on PTT crystallization; the presence of 1 wt. % MMT shifts the initial and peak crystallization temperatures of the 70/30 PTT/PC blend to ~17 °C and ~32 °C, respectively. Additionally, the full width at half maximum (FWHM) narrows by ~45%, and the ΔHc increases by 3.7 J.g−1. The accelerating effect of MMT is determined by its distribution and dispersion which depends on the shear intensity, mixing mode, and loading. MMT is easier to exfoliate via the two-step method than by the one-step method. The distribution in the PTT phase is enriched along the phase interface forming an MMT layer. This endows sections of the PTT with abundant nuclei and thus crystallization is promoted markedly compared with the one-step method. Moreover, the finer MMT migrates more readily to the interface to cause a much smoother phase interface. However, a secondary crystallization peak appears when the shear force is not sufficient enough to make MMT finely dispersed, in case of the two-step method and the MMT content is increased to 3 wt. %. The mixing temperature shows little effect on the acceleration of MMT on the crystallization of PTT/PC compared with the shear force. Only when MMT did not exfoliate or uncomplete did the presence of epoxy resin help to promote crystallization because of the improved MMT dispersion.

Influence of Polycarbonate on the Crystallization Behavior of Poly(Trimethylene Terephthalate)/Polycarbonate Blends

To determine the factors influencing the retardation of the crystallization of poly(trimethylene terephthalate) (PTT) when PTT is blended with polycarbonate (PC), different PTT/PC blends were prepared via the melt mixing method. The relationships between the crystallization behavior and blend composition, as well as the phase morphology, were investigated. The results showed that the predominant reason for the retardation in crystallization is due to the PC content and phase morphology. The PC influences the crystallization of PTT via two methods. First, it retards PTT crystallization. Secondly, the PC exhibits a nucleation effect on the PTT crystallization which is, however, much weaker compared to the negative effect PC exerts with regards to PTT crystallization. When the processing temperature and shear rate remains unchanged, the two effects of PC determine the crystallization behavior of the blend. The phase morphology, which is strongly dependent on the mixing temperature and the shear rate, and which is also related to mixing time, had an appreciable impact on PTT crystallization. In the case of similar adhesion with the interface, a finer PC phase domain would show a slightly stronger nucleation effect on PTT crystallization.

Crystallization Studies of Poly(trimethylene terephthalate)/Silica Nanocomposites Prepared by Sol-Gel Technique.

Poly(trimethylene terephthalate) (PTT)/silica nanocomposite films were successfully fabricated using a novel sol–gel approach. The synthesis of these nanocomposites is being carried out by hydrolysis and condensation of tetraethoxysilane using trifluoroacetic acid with a small amount of water. The scanning electron microscopy and zetasizer result showed that the silica particles with a size range of 80–100 nm were homogeneously dispersed in the PTT matrix. The effect of different amounts of silica on crystallization of PTT was investigated using X-ray diffraction, differential scanning calorimetry (DSC), and optical microscopy. Polarized light microscopic results revealed that the spherulite size gradually decreased with increasing silica loading and increased with crystallization temperature for a given nanocomposite during isothermal melt crystallization. PTT with a small amount of SiO2 melt crystallized at low temperatures showed banded spherulites. DSC results revealed that nonisothermal cold crystallization temperature decreased with silica content, whereas no significant change in nonisothermal melt crystallization behavior was observed with silica content. The crystallinity of isothermally melt crystallized PTT increased with both crystallization temperature and silica loading.

Reorganization of semicrystalline polymers on heating: Analyzing common misconceptions in the interpretation of calorimetric data. Response on the “Comment on “Re-exploring the double-melting behavior of semirigid-chain polymers with an in-situ combination of synchrotron nanofocus X-ray scattering and nanocalorimetry” by Dimitri A. Ivanov et al. [Euro. Polym. J. 81 (2016) 598–606.

In our recent article entitled “re-exploring the double-melting behavior of semirigid-chain polymers with an in-situ combination of synchrotron nanofocus X-ray scattering and nanocalorimetry” (European Polymer Journal 81 (2016) 598–606), we investigated complex thermal behavior of a typical semirigid-chain polymer, poly(trimethylene terephthalate), PTT. In the comment on our paper published by Furushima and colleagues (EUROPOL_2017_495), our interpretation of the multiple melting phenomenon was seriously questioned. In particular, it was argued that the main drawback in our paper was due to the fact that the critical heating rate above which the PTT structure does not reorganize after isothermal melt crystallization at 180°C should be 2000°C·s−1, i.e. higher than the rate of 1000°C·s−1 used in our experiments. It is noteworthy that the authors of the Comment performed all their experiments on a different grade of PTT, which makes quantitative comparison with the recrystallization rates in our experiments problematic. In the present paper, we employ a combination of X-ray scattering with fast single-photon-counting X-ray detection and custom-built ultrafast chip calorimeter to show that the claims of Furushima and colleagues are not relevant to our case and, therefore, cannot be generalized. Indeed, even for a PTT sample melt-crystallized at 150°C, which recrystallizes on heating much faster than the sample crystallized at 180°C, the critical heating rate is safely below 500°C·s−1. To further clarify the issue, we discuss on a general misconception in the literature concerning the interpretation of double melting peaks in DSC traces as being indicative of a melting/recrystallization process. Since many works in the field including the discussed one are based entirely on calorimetric data, the direct information on the structure is simply missing. Therefore, such interpretations of the thermal behavior evoking the so-called “single crystal population” are clearly inadequate. By contrast, on the basis of on-time X-ray scattering recorded simultaneously with ultrafast chip calorimetry we unambiguously show that even in the absence of reorganization processes a uniform population of PTT crystals formed at isothermal conditions exhibits double melting. In agreement with our earlier publications (e.g., Macromolecules 41 (2008) 9224–9231) this is explained by strong interactions between amorphous and metastable crystalline regions, which are very characteristic for the semirigid-chain polymer family.

Comment on “Re-exploring the double-melting behavior of semirigid-chain polymers with an in-situ combination of synchrotron nanofocus X-ray scattering and nanocalorimetry” by Ivanov et al. [European Polymer Journal 81 (2016) 598–606.

Ivanov et al., European Polymer Journal 81 (2016) 598–606, conclude that “the phenomenon of the double (or multiple) melting behavior [in poly(trimethylene terephthalate) (PTT)] is not necessarily coupled to the melting–recrystallization processes and can be observed even in the absence of any recrystallization”. To further clarify this long standing issue, the multiple-melting behavior of isothermally crystallized PTT was examined using differential scanning calorimetry (DSC) and fast scanning chip calorimetry (FSC) in a wide range of heating rates (0.1Ks−1–60,000Ks−1). The critical heating rate to suppress recrystallization, βcritical, was determined as 2000Ks−1 from the analysis of heating rate dependence of melting temperature. Melting peaks observed below βcritical are due to the melting of recrystallized crystals, which are formed during slow heating. On the other hand, above βcritical, a single endothermic peak originated from the melting of initially formed crystals is observed. The result of thermal analysis strongly suggests that a single population of crystals is formed during isothermal crystallization of PTT. The heating rate of 1000Ks−1, as used by Ivanov et al., was therefore not fast enough to suppress recrystallization.

Isothermal Crystallization Kinetics Effect on the Tensile Properties of PLA/PTT Polymer Composites

A poly(lactic acid)/poly(trimethylene terephthalate) (PLA/PTT) composite was prepared by melt blending to improve the PTT crystallization rate. Morphology analysis of PLA/PTT fractured surfaces demonstrated the compatibility of its components. Thermogravimetric analysis revealed that the thermodegradation of a PLA/PTT sample was higher than that of PLA. Differential scanning calorimetry was used to evaluate the crystallization behavior. The Avrami equation described the isothermal crystallization kinetics. The Hoffman–Weeks parameters indicated that the PLA presence increased slightly the PTT nucleation. The tests of PLA, PTT, and PLA/PTT specimens in tension showed that a percent elongation of the PLA/PTT composite was between that of PLA and PTT; however, the tensile strength of the PLA/PTT composite was similar to that of PLA.

Biocomposites with Size-Fractionated Biocarbon: Influence of the Microstructure on Macroscopic Properties.

This study is an experimental investigation of using biocarbon as renewable carbonaceous filler for engineering-plastic-based blends. Poly(trimethylene terephthalate) (PTT) and poly(lactic acid) (PLA) combined with a terpolymer were selected as the blend matrix. Biocarbon with various particle size ranges was segregated and used as filler. Depending on the particle size and aspect ratio of the biocarbon used, the microstructure of the composite was found to change. Composites having a biocarbon particle size range of 20–75 μm resulted in a morphology showing better dispersion of the blend components when compared with composites containing other biocarbon particle size ranges. Furthermore, the addition of epoxy-based multifunctional chain extender was found to result in much finer morphologies having dispersed polymer particles of very small size. Impact strength increased significantly in composites that possessed such morphologies favoring high energy dissipation mechanisms. A maximum notched Izod impact strength of 85 J/m was achieved in certain composite formulations, which is impressive considering the inherent brittleness of PTT and PLA. From rheological observations, incorporation of biocarbon increased viscosity, but the shear-thinning behavior of the matrix was preserved. By increasing the injection mold temperature, fast crystallization of PTT was achieved, which increased the heat deflection temperature of composites to 80 °C. This study shows that composites with overall improvement in mechanical and thermal performance can be produced by selecting biocarbon with appropriate particle sizes and suitable processing aids and conditions, which all together control the morphology and crystallinity.

Interfacial interactions of thermally reduced graphene in poly(trimethylene terephthalate)-epoxy resin based composites

Nanocomposites containing thermally reduced graphene (TRG) have been prepared with poly(trimethylene terephthalate) (PTT) plasticized with (bisphenol-A diglycidyl ether) (BADGE), a cross-linkable additive. Morphology of the PTT–BADGE blend was dependent on preference for interaction of TRG with PTT or BADGE and nucleation activity of TRG toward PTT. PTT-TRG and PTT-BADGE-TRG nanocomposites with different BADGE-TRG ratios were prepared by a melt mixing technique facilitated by miscibility of PTT and BADGE. The influence of TRG on crystallization nucleation, kinetics and morphology was measured using differential scanning calorimetry and wide-angle X-ray scattering. Crystallization of PTT caused phase separation of BADGE, though PTT–BADGE remained miscible in PTT amorphous regions. BADGE created increased flexibility of PTT though dynamic mechanical properties were moderated by TRG, both directly as a filler and as a result of enhanced crystallization. Synergistic improvement in modulus was observed at particular compositions attributed to a change in morphology of an immobilized zone consisting of BADGE and TRG within amorphous fractions of PTT. The results are of consequence for design of materials using a semi-crystalline polymer, for applications where simultaneous use of a processing aid, plasticizer and nano-reinforcement.

Analysis of structure transition and compatibility of PTT/PC blend without transesterification

Poly(trimethylene terephthalate)/polycarbonate (PTT/PC) blends were prepared by solvent mixing to avoid transesterification during high temperature blending. The influences of compositions on the thermal behavior, crystallization morphology and structure of the blends were studied. FTIR results indicated that there was no COO linking to two phenyl groups on each side chain and DSC results supported no transesterification reaction. DSC curves showed that Tc and Tmc increased to maximum range when PC contents were between 7 wt%-15 wt%, however, Tm decreased constantly with the increase of PC contents. It was observed from POM that PTT spherulitic morphology and crystallization kinetics were obviously influenced by the change of PC contents. Structural evolutions during cooling were investigated by SAXS which showed Lc of PTT remained a constant with different PC contents and also fixed during crystallization, nevertheless, it revealed a maximum value of Lnc for sample PTT93. It was concluded that PC chains could be permeated into not only amorphous crystallite structure but also amorphous lamellae structure and 7 wt% PC content was supposed to be the “proper” penetration amount into PTT lamellae structure which led to a maximum capacity of amorphous lamellar layer. Fringedmicelle crystal model was adopted to illustrate semi-crystalline physical structures of the blend in two kinds of component aggregation states.

Morphological features and crystallization behavior of the conductive composites of poly(trimethylene terephthalate)/graphene nanosheets

ABSTRACTPoly(trimethylene terephthalate) (PTT) composites filled with well‐dispersed graphene nanosheets (GNSs) were prepared through a coagulation method. The effects of increased GNS concentration on variations in the structure and properties of the PTT matrix, such as its electrical conductivity, crystallization kinetics, melting behavior, and crystal morphology, were investigated. Several analytical techniques were used, including electrical conductivity measurement, differential scanning calorimetry, Fourier transform infrared spectroscopy, wide‐angle X‐ray diffraction, polarized light microscopy, transmission electron microscopy (TEM), and thermo‐gravimetric analysis (TGA). Electrical conductivity increased from 1.8 × 10−17 S/cm for neat PTT to 0.33 ± 0.23 S/cm for PTT/GNS composites with 2.97 vol % GNS content. Percolation scaling laws were applied, and then threshold concentration and exponent were determined. In the case wherein liquid nitrogen was used to quench the melt, a mesomorphic phase was formed despite the extremely short crystallization time after adding high GNS contents. PTT crystallization rate increased with the gradual addition of GNSs. The enhanced crystallization kinetics was attributed to the high nucleation ability of GNSs to induce epitaxially grown lamellae on their surfaces, as revealed by TEM. PTT nuclei were randomly developed on the GNS surface to form the lamellae. However, crystallinity reached its maximum value near the electrical percolation threshold because the PTT chain mobility was confined after the GNS–GNS network formed. The growth of PTT banded spherulites in the bulk was still observed for composites with high GNS content, and TGA results revealed that the GNS‐filled PTT composites had excellent thermal stability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43419.

Effect of Organoclay Platelets on Crystallization of PTT/EVA-g-MA Blends: Non-Isothermal Melt Crystallization Kinetics

PTT/EVA-g-MA (80/20 w/w) nanocomposites were prepared by the melt mixing with different organoclay (OMMT) loading. The effect of OMMT on the non-isothermal crystallization kinetics of composites was investigated by DSC. The Avrami and Ozawa methods were used to describe the non-isothermal crystallization process of pure PTT and composites with various loading of OMMT. The Avrami analysis results show that the crystallization rate of 80/20 (w/w) PTT/EVA-g-MA blends with the OMMT is faster than that of pure PTT. The Ozawa analysis can describe the non-isothermal crystallization of pure PTT very well, but it was rather inapplicable for the 80/20 (w/w) PTT/EVA-g-MA blends with various amounts of the clay.

Effect of Molecular Orientation on the Cold Crystallization of Amorphous–Crystallizable Polymers: The Case of Poly(trimethylene terephthalate)

The effect of molecular orientation on cold crystallization of amorphous crystallizable polymers was examined using poly(trimethylene terephthalate) (PTT) films drawn to different draw ratios and strain rates. A combination of differential scanning calorimetry (DSC) and polarized Fourier transform infrared (FTIR) spectroscopy was employed to examine structural evolution and nonisothermal crystallization kinetics. The cold crystallization temperature (Tc), cold crystallization exotherm (ΔHc), and subsequent melting temperature (Tm) were carefully correlated to the overall molecular orientation. For the first time, the overall molecular orientation was shown to have an inverse relationship to the cold crystallization temperature, as well as the cold crystallization exotherm. Nonisothermal cold crystallization has not occurred when the overall orientation exceeded the critical value of 0.43. The kinetics of nonisothermal cold crystallization of PTT with a different overall molecular orientation has been investigated and the Avrami equation has been applied to evaluate the kinetic parameters. An increase in the rate constant and a decrease in the Avrami exponent suggested that cold crystallization is faster for a PTT film with a high overall molecular orientation and a change in growth geometry with orientation. This study demonstrates that overall molecular orientation affects the cold crystallization kinetics of amorphous–crystallizable polymers.

Strain-Induced Crystallization and Conformational Transition of Poly(trimethylene terephthalate) Films during Uniaxial Deformation Probed by Polarized Infrared Spectroscopy

The structure development during the drawing of PTT films immediately above the glass transition temperature at two different strain rates (8.33 × 10–3 and 8.33 × 10–4 s–1) has been investigated using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. It was found that both the melting temperature and the crystallinity development are dependent on the strain rate. The cold crystallization peak decreases with increasing draw ratio and disappears completely beyond a draw ratio of 2.5. DSC results showed that the decreasing strain rate delays crystallization and reduces the rate of crystallization. The bands at 1358 and 976 cm–1 were chosen to determine the gauche and trans conformations of methylene segments in PTT as a function of the draw ratios and strain rates. It was found that the crystalline gauche conformation increases at the expense of the amorphous trans conformation during the strain-induced crystallization of PTT. The conversion of the amorphous trans conformation into the crystalline gauche conformation is also delayed at lower strain rate, which is consistent with our DSC observation. Polarized IR spectroscopy was used to measure the crystalline and the amorphous orientation functions separately with draw ratios and strain rates, and it was demonstrated that the crystalline orientation develops rapidly with strain-induced crystallization and that the amorphous orientation stays constant up to draw ratio of 2.5 and increases slowly above a draw ratio of 2.5, which is typical behavior for flexible chain polymers.

Crystallization behavior of poly(trimethylene terephthalate)/mesoporous silica SBA-15 composites prepared by in situ polymerization

Poly(trimethylene terephthalate)/mesoporous silica SBA-15 composites were prepared by in situ hybridization for the crystallization study. The results show that SBA-15 particles are well compounded with PTT, forming nanostructured composite system. Although the addition of SBA-15 particles results in an evident decrease of PTT molecular weight, those well dispersed mesoporous particles can compensate effectively for the property degradation of PTT. Besides, the addition of SBA-15 particles has large influence on the crystallization of PTT. The composites show higher crystallization temperature and rate than that of the neat PTT. But the presence of SBA-15 impedes PTT chain segment movements somewhat. In comparison with neat PTT, therefore, the composites present lower folding surface free energy and higher diffusion activation energy. The kinetic analysis results elucidate that the crystallization rate of PTT is dominated by the nucleation item instead of the growth one.

Structural Differences between Cold- and Melt-Crystallized Poly(trimethylene terephthalate) Samples

Time-resolved Fourier transform infrared spectroscopy was used to investigate the structural differences between cold- and melt-crystallized poly(trimethylene terephthalate) (PTT) samples. To elucidate the arrangement of different chain segments in the crystalline phase obtained through different crystallization processes, characteristic bands associated with the phenylene rings, the CH2 segments, and the C-O-C segments were followed during the cold and the melt crystallizations. The results show that the alignment of the phenylene rings and the C=O groups in the PTT crystals produced via cold- and melt-crystallization processes are essentially the same, while the alignment of the CH2 segments depends on the crystallization condition. It was found that the CH2 segments in the melt-crystallized sample were more stable than those in the cold-crystallized sample. This was ascribed to the different crystallization environment. Melt-crystallized PTT chains have higher mobility, and the variation of flexible segments is quicker than that of the rigid segments. However, in cold crystallization, the CH2 segments are restricted by the adjacent environment in the glass state, which weakens their capability of transforming their conformation; this leads to a cooperative change of CH2 segments, phenylene rings, and C=O groups. Therefore, the stability of CH2 segments in crystalline structure is lowered accordingly.

Isothermal crystallization kinetics of poly(trimethylene terephthalate)/multiwall carbon nanotubes composites

The isothermal crystallization kinetics of poly(trimethylene terephthalate) (PTT) in the presence of varying amounts of multiwall carbon nanotubes (MWCNT) have been investigated using differential scanning calorimetry (DSC) and analyzed using Avrami and secondary nucleation theory. Polarized light microscopy (PLM) was used to study the crystal morphology of PTT/MWCNT composites. The results showed that the presence of MWCNTs in PTT acted as an effective nucleating agents and lead to the spherulitic morphology. The decrease in the spherulites size on MWCNT addition was observed by polarized light microscopy. Using values of transport parameters ( $$ U* = 1500{\text{ cal mol}}^{ - 1} , \, \Updelta T =T_{\text{g}} - 30\, $$ °C) together with experimentally determined values of equilibrium melting temperature [ $$ T^{\text{o}}_{\text{m}} $$ (245.2 °C)] and glass transition temperature [ $$ T_{\text{g}} $$ (45 °C)], the nucleation parameter, $$ K_{\text{g}} $$ and $$ \sigma_{\text{e}} $$ were determined for PTT and PTT/MWCNT composites according to Lauritzen–Hoffman theory. The decrease in the values of these parameters on MWCNT addition is in agreement with the fact that the rate of crystallization of PTT increased in the presence of MWCNTs.

Exploring the Origin of Crystalline Lamella Twist in Semi-Rigid Chain Polymers: the Model of Keith and Padden revisited

The microstructure of banded spherulites of a typical semirigid-chain polymer, poly(trimethylene terephthalate), PTT, has been explored with microbeam X-ray diffraction. It is shown that during microbeam scans along the spherulite radius, different diffraction peaks exhibit oscillations with the same periodicity, which means that the lamellar twist is strictly uniform and regular. The twisted PTT crystals formed from the melt at 170 °C reveal a one-to-one correlation between the handedness and growth axis polarity. Thus, the lamellae are right-handed for the growth along the negative growth direction (−a) while they are left-handed for the positive growth direction (+a). This is in line with predictions of the KP-model, although the original model cannot explain why, for example left-handed crystals have to grow along (−a). The direction of the chain tilt in the lamellar crystal correlates with the lamellar handedness as postulated by the KP-model. However, the measured chain tilt in the crystal (4°) is too faint to be the primary source of the surface stresses required for twisted lamellar growth.

Mechanical Property, Crystal Morphology, and Nonisothermal Crystallization Kinetics of Poly(Trimethylene Terephthalate)/Maleinized Acrylonitrile-Butadiene-Styrene Blends

The mechanical properties, morphology, crystallization, and melting behaviors and nonisothermal crystallization kinetics of poly (trimethylene terephthalate)(PTT)/maleinized acrylonitrile-butadiene-styrene (ABS-g-MAH) blends were investigated by an impact tester, polarized optical microscopy, and differential scanning calorimetry (DSC). The results suggested that the ABS-g-MAH component served as both a nucleating agent for increasing the crystallization rate and as a toughening agent for improving the impact strength of PTT. When the ABS-g-MAH content was 5wt.%, the blend had the best toughness and a high crystallization rate. The blends showed different crystallization rates and subsequent melting behaviors due to their different ABS-g-MAH contents. The Ozawa theory and the method developed by Mo and coworkers were used to study the nonisothermal crystallization kinetics of the blends. The kinetic crystallization rate parameters suggested that the proper contents of ABS-g-MAH can highly accelerate the crystallization rate of PTT, but this effect nearly reaches saturation for ABS-g-MAH contents over 5%. The Ozawa exponents calculated from the DSC data suggested that the PTT crystals in the blends have similar growth dimensions as those in neat PTT, although they are smaller and/or imperfect. The effective activation energy calculated by the method developed by Kissinger also indicates that the blends with higher ABS-g-MAH content were easier to crystallize.

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

AbstractDouble 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

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

AbstractPoly(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 (t1/ 2) is much shorter, the nonisothermal crystallization kinetic rate constant (Zc) is bigger at a given cooling rate, the cooling rate [Fz(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