Designed Monomers and Polymers最新文献

PBT and PET are subjected to thermal-oxidative degradation and thermomechanical degradation during the process of melt blending, which affect the polymer structure and properties. The effect of feed properties of PET and the addition of modified nanoparticles on blends are a question worthy of discussion. This work describes the melting and thermal stability, the crystallization behavior and non-isothermal crystallization kinetic, the rheological behaviors and mechanical properties of several PBT/PET blends prepared by twin-screw melt extrusion. Results show that the molecular chain of the polyester blends obtained by stable extrusion are not significantly degraded, there is only one obvious melting peak and crystallization peak on the thermal analysis curves, and the melting point is lower than either of the two polyesters. An appropriate amount of SD can effectively reduce the crystallization rate of the PBT material and extend the crystallization time. The rheological behavior of PBT/PET blends is complicated than PET raw materials and SD, as well as the melt processing temperature and shear rate will all affect the rheological behavior of the blends. For example, at low shear rate, polyester blends with SD exhibit strong shear thinning behavior. In general, the SD content affects the rheological property of blends in a way similar to the law of influence on crystallization behavior. When SD content is 0.3 wt%, a polyester product with higher elongation at break than pure PBT can be obtained. This can provide a useful reference for preparing commercialized polyester blend products with good melt processability and elongation by simple blending.

In the present work, a reaction methodology was implemented using a batch reactor, which synthesized glycerol carbonate (GC) using glycerin and CaCO₃. A crystallographic analysis of CaCO₃ was performed to determine its crystalline form. The obtained product was characterized by infrared spectroscopy, thermogravimetric analysis and nuclear magnetic resonance (¹H and ¹³C). Our analysis demonstrated that the obtained product with the implemented reaction methodology has GC, FTIR showed the signals of the carbonyl groups, and the NMR spectrum confirmed the presence of cyclic carbonate structure in addition to linear carbonates. The thermogravimetric study showed that the thermal stability of the product is highly similar to that reported for GC. These results exhibit that the synthesis process produces linear and cyclic carbonates.

In the present study, via using a ligand featuring oxalamide groups N,N'-bis(4-phthalic acid) (H₄L), two new Cu(II) and Co(II)-containing coordination polymers with the chemical formulae of [Cu₂L(H₂O)₄]_n (1) and [Co(H₂L)(H₂O)₂]_n (2) have been successfully prepared via reaction of the corresponding metal salts with the H₄L ligand. The as-prepared two coordination polymers have been studied via the single crystal X-ray diffraction, elemental analysis, powder X-ray diffraction and thermogravimetric analysis. Their therapeutic effect and mechanism for ovarian cancer was evaluated and explored. Firstly, the inhibitory activity of the new compounds on the proliferation of the ovarian cancer was measured with CCK-8 assay after compound treatment. Besides, the relative expression of the estrogen receptor on the ovarian cancer cells after compound treatment was also determined with real-time RT-PCR assay.