The poly(4-hydroxybenzoate) (PHBA) oligomer was synthesized by using the monomer of 4-acetoxybenzoic acid (PABA), and its blends with poly(trimethylene terephthalate) (PTT) are prepared by melt-blending at 250oC in nitrogen. Their chemical structure characterization and crystal morphology were investigated by using the fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1HNMR), and polarizing optical microscopy, respectively. The results suggest that PHBA oligomer with 3 polymerization degree was synthesized and it is a thermotropic liquid crystal with the nematic characteristics. When the blends crystallize from melt, because the rigid oriented PHBA molecules becomes the nucleating agents for PTT molecules’ crystallization, much transcrystalline layers formed in the blends, although the crystalline PTT/PHBA blends show spherulites morphology character without observing nematic LC phase.

Poly (ethylene terephthalate)/poly (trimethylene terephthalate) (PET/PTT) blends were prepared and their melting and crystallization properties were investigated by differential scanning calorimetry (DSC). The glass transition temperatures suggest apparently that PET and PTT have good miscibility at amorphous state. The blends with more PET content less likely undergo a melting/recrystallization process during DSC heating scan. In the blends, PET component with higher supercooling degree will crystallize first, and then the crystallites of PET will be the nucleating agents for PTT, which greatly improves the crystallization rate of PTT.

The morphological, mechanical and rheological properties of poly(trimethylene terephthalate)(PTT)/maleinized acrylonitrile-butadiene-styrene (ABS-g-MAH)/short carbon fiber (SCF) composites were investigated by the scanning electron microscopy(SEM), universal tester, impact tester and capillary rheometer, respectively. The SEM images of the composites’ fracture surface show that the fracture surface is rough and SCF are randomly dispersed in the matrix resin, and there is a good interfacial interaction between SCF and PTT. The composites show the maximum tensile strength when adding 10-23% SCF into PTT/ABS blends. The rheology results show that the composites melt are pseudo-plastic fluid, and the melt apparent viscosity of the PTT/ABS/SCF composites increases with increasing SCF content.

The crystal morphology and thermal properties of the PA6/PP-g-MAH/POE blends prepared by twin-screw extruder were studied by polarized optical microscopy (POM) and differential scanning calorimetry (DSC) respectively. The results suggest that the crystal morphology of PA6 is acicular crystal while PP-g-MAH is micro-spherulites; The acicular crystals form across POE phase to PA6 phase, and the acicular crystals of PA6 in the POE phase have better regularity in dimension than those in amorphous PA6 phase. Acting as a compatibilizer, PP-g-MAH improves the miscibility of PA6 and POE, leading to the glass transition temperature of the blends decreases gradually with increasing POE contents. PA6 and PP-g-MAH can crystallize individually, and the formed PA6 crystals induced the crystallization of PP-g-MAH at higher temperature; furthermore, PP-g-MAH and POE components can increase the crystallization rate of PA6.

The dynamic mechanical properties, phase morphology and thermal stability of the poly(trimethylene terephthalate)/maleinized poly(octene-ethylene)/organo-montmorillonite nanocomposites (PTT/POE/OMMT) were investigated by using the thermodynamic mechanical analyzer (DMA), transmission electron microscopy (TEM) and thermal gravimetric analyzer (TGA), respectively. The results suggest that the modulus of elasticity of the PTT/POE/OMMT nanocomposite increases, and the glass transition temperature first slightly decreases and then increases with increasing OMMT content because that the TPP plays the role of plasticizer and OMMT plays the role of reinforcing agent. OMMT disperse evenly in the polymer matrix with most of the strip-like sheet morphology. The addition of the OMMT does not apparently affect the thermal stability of the PTT/POE/OMMT nanocomposite.