Advanced Materials Research Vols. 284-286

Abstract: A series of amphiphilic block copolymers mPEO-b-PCL with different PCL molecular weight were successfully prepared by combination of anionic ring-opening polymerization with coordination-insertion ring-opening polymerization. Firstly, the linear mPEO was prepared by anionic ring-opening copolymerization of EO with 2-(2-methoxyethoxy) ethoxide potassium as the small molecule initiators, then the mPEO as the macroinitiator was used to initiate the ring-opening polymerization of CL, in the absence of Sn(Oct)₂ as the catalyst, and amphiphilic block copolymers mPEO-b-PCL were obtained. By changing the ratio of monomer and macroinitiator, prepared a series of different molecular weight mPEO-b-PCL. The structure of intermediates and final products were characterized by ¹H NMR and GPC. The critical micelle concentration (cmc) of the final copolymer was measured. In addition, the sizes and morphologies of the obtained micelles at different PCL chains were studied with Laser nano-particle size analyzer and transmission electron microscopy (TEM).

Abstract: The polystyrene/styrene-ethylene/butylene-styrene composites were prepared by melt blending process in this paper. The mechanical properties of PS/SEBS composites were analyzed. The results showed that the impact strength of PS/SEBS composites could be increased with the content increasing of SEBS, meanwhile the tensile strength was lower than pure polystyrene. When the content of SEBS increased to 13 wt.%, the impact strength of PS/SEBS composites was 2.4 times higher than that of pure PS. The fractured surfaces of the specimens were characterized by scanning electron microscopy(SEM). The results showed that the impact fractured surfaces produced a lot of sliding along with the addition of SEBS. The particles of SEBS could be well dispersed in polystyrene matrix. From rheological properties studies and the values of the torque, it was suggested that the maximum torque of PS/SEBS composites decreased drastically.

Abstract: A binary and ternary rare earth complexes were synthesized. The structure and composition of the complexes were characterized by FT-IR and Elemental Analyzer. It is found that the complexes have excellent fluorescence intensity and thermal stability. Photoluminescent measurements show that Phenanthroline (Phen) could efficiently transfer energy to Eu³⁺ and sensitize the luminescence of Eu³⁺. The copolymers of complexes, methyl methacrylate (MMA) and methacrylic acid (HMA) emit characteristic fluorescence of Eu³⁺. The fluorescence intensity enhanced with the complexes content increasing. But the apparent copolymers of Eu(AA)₃ have stronger luminous intensity than that of Eu(AA)₃Phen under limit solubility because Phen reduces the content of solvable Eu³⁺ in the mixture of MMA and HMA.

Abstract: A kind of semi-aromatic polyamide, poly(dodecamethylene terephthalamide) (PA12T) was synthesized via a three-step reaction of terephthalic acid and 1,12-dodecanediamine. The structure of the prepared PA12T was characterized by Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance (¹H-NMR). The thermal behaviour of PA12T was determined by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Melting temperature (T_m), glass transition temperature (T_g) and decomposition temperature (T_d) of PA12T are 311°C, 144°C and 429°C, respectively. Isothermal crystallization kinetics of PA12T have been investigated in the temperature range of 270-280°C using DSC. The activation energies (ΔE) were determined to be -170.4 kJ/mol for the isothermal crystallization processes by the Arrhenius’ methods.

Abstract: A novel nanofiller containing layered organo-modifed montmorillonite (oM) and mesoporous silica micro-sphere (MS) was prepared by in situ deposition method, and the microstructures and morphologies of this nanofiller were characterized by Fourier transform infrared spectrometry (FTIR) X-ray diffraction (XRD) and transmission electronic microscopy (TEM). EP/oM-MS nanocomposite was obtained by adding oM-MS to EP matrix. Morphologies and mechanical of the new ternary nanocomposite were investigated. For purpose of comparison, the corresponding binary nanocomposites, i.e., EP modified with either oM or MS, were tested as well. The test results of mechanical properties show that oM obviously improves the strength of EP and MS enhances the toughness of EP, but oM-MS exhibits synergistic effect on toughening and reinforcing of EP.

Abstract: Narrow size distribution Palladium nanoparticles was synthesized by adding Pd precursor into a modified PMHS polymer solution, and then jelled by aluminium. The multi-functional polymer was characterized by NMR; Pd nanoparticle samples were characterized by TEM and catalytic activity was tested in methane partial oxidation reaction.

Abstract: Poly (phenylene sulfide) (PPS)/nano-TiO₂ composites were prepared by DAKA miniature blending instrument. Isothermal crystallization behavior of PPS composites at 245°C, 250°C, 255°C and 260°C were investigated by means of DSC. The crystallization time of PPS composites is shorter than which of neat PPS at the same crystallization temperature. The Avrami equation was used to analyze DSC data. Results showed that neat PPS is homogeneous nucleation at lower crystallization temperature, which is heterogeneous nucleation at higher crystallization temperature contrarily. PPS/nano-TiO₂ composites are heterogeneous nucleation at various crystallization temperature, nano-TiO₂ particles play a role of nucleating agent.

Abstract: The copolymerization reaction between glucose and acrylamide was initiated using Ce(NH₄)₂(NO₃)₆ as initiator under microwaves heating at 60~80°C. The product is glucose-acrylamide copolymer. The synthesis experiment shows that the copolymerization was initiated quickly when the dosage of glucose is 2~30%. When the optimal dosage of glucose is 20%, the average rate of acrylamide and glucose is 10∶1 in the long chain of the copolymer molecule; the average molecular weight of the copolymer is 3.61×10⁸. The flocculating test showed the water-solubility of the copolymer is better than polyacrylamide, and with the same flocculating effect. The copolymer will easy to be biodegraded because that with amount of the glucose in its long chain molecules.

Abstract: The kinetics of the thermal degradation of Polyarylene ether natriles (PEN) (crosslinked and uncrosslinked) were investigated by thermogravimetric analysis (TGA). The corresponding kinetic parameters of PEN were determined using Flynn–Wall–Ozawa method and Friedman method, respectively. Satava method was also used to discuss the probable degradation mechanisms of PEN. The results showed that the activation energy obtained from Flynn–Wall–Ozawa method was in good agreement with the value obtained from Friedman method. The solid-state decomposition mechanisms of PEN and crosslinked PEN were A2 type (nucleation and growth) and R2 type (phase boundary controlled reaction), respectively. The activation energy and initial decomposition temperature of crosslinked PEN were higher than that of PEN, which indicates that crosslinking treatment is effective to enhance the thermal stability of PEN.

Abstract: The unique physical properties of leather make it ideally suited for the manufacture of a variety of products. Retanning has important effects on the mechanical and physical properties of the resultant leather. In this paper, a novel amphoteric acrylic copolymer as retanning material was prepared by free radical copolymerization. The effects of this copolymer on the physical properties of the resultant leather have been investigated by measuring physical and mechanical indexes of the retanned leather. The function mechanism of this copolymer was also researched. Results showed that this copolymer could improve the properties of the resultant leather including softness and strength, and increase leather’s dyeability in contrast to anionic acrylic polymer.