Advanced Materials Research Vols. 197-198

Abstract: Cationic starch was prepared from maize starch, with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride used as cationic reagent, by our specific solvent process, which was different from dry procedure. In conventional solvent process, the solvents were hydrophilic and sodium hydroxide was employed as catalyst. Metal sodium as a substitute for sodium hydroxide in the synthesis of high DS (degree of substitution) cationic starch could be obtained using dioxane as solvent. A L₉(3⁴) orthogonal analysis was used in this work and results suggested the best combination of the reaction condition was A₂B₂C₁, where the reaction time, temperature and weight of metal sodium were 2 h, 80 °C and 0.5 g, respectively. FTIR spectra revealed a special peak (1450 cm^-1) of cationic starch confirming the existence of cationic groups in cationic starch. In a model of neutralizing the anionic groups, it revealed that the content of 0.8% (w/w) cationic starch was the optimum dosage.

Abstract: The ultra-fine denier PET full drawing yarn (PET-FDY) with monofilament linear density equal to 0.38dTex was produced. During the practical process of ultrafine denier PET-FDY, the yarn should be heat-set at certain temperature following the drawing process in order to improve the mechanical properties and reduce the boiling water shrinkage. The influence of heat-setting temperature on the structure and performance of ultra-fine denier PET FDY was studied in this paper. With heat-setting temperature increasing, crystalline in PET FDY became perfect and crystallite size became bigger. According to the density method, crystallinity was augmented. Crystal orientation factor and overall orientation factor were both increased. The tenacity and tensile stress at 10% strain of PET FDY were increased and the breakage percentage and boiling water shrinkage were reduced with the heat-setting temperature increasing.

Abstract: In this paper three kind of water borne polyurethane are synthesized. FTIR identify the structure of 2-hydroxypropyl acrylate terminated water borne polyurethane with block PDMS. It is found that Si-WPUA has excellent water-resistance, good toughness, and good tensile strength. So, the work has been found the method which could improve water resistance and not decrease mechanical properties. It is hoped that the modified polyurethane could be used as coatings superior to the solvent-borne systems.

Abstract: Amorphous nickel hydroxide powder codoped with Fe³⁺ and PO₄^3- was synthesized by micro-emulsion precipitation method combined with rapid freezing technique. The microstructures of the prepared samples were characterized by XRD, SEM, EDS, and Raman spectra. The electrochemical performance of the prepared samples was analyzed by cyclic voltammetry, electrochemical impedance spectroscopy, and charge-discharge tests. The results showed that this amorphous nickel hydroxide codoped with Fe³⁺ and PO₄^3- resulted in more structural defects within the nickel hydroxide. The Fe³⁺ and PO₄^3- codoping could increase the specific discharge capacity and improve the electrochemical reversibility of the amorphous nickel hydroxide.

Abstract: The morphology, shock absorption and dynamic mechanical properties of a new architectured multifunctional materials- polyaspartic esters (PAE) based ployureas were investigated through FTIR, atomic force microscope(AFM), drop-weight test and dynamic mechanical analysis(DMA). The PAE based polyureas were prepared from synthesized PAE and hexamethylene diisocyanate（HDI）trimer /polytetramethylene ether glycol (PTMG) prepolymer. The FTIR results indicated that hydrogen-bonded urea carbonyl of PAE based polyurea was 76.1%, and the length of hydrogen bonding was 0.306nm. The microphase separation phenomenon of the PAE based polyureas were observed directly through AFM topography studies. PAE based polyureas exhibited unique shock absorption and dynamic mechanical properties.

Abstract: New polyaspartic ester (PAE) chain extender named PAE-f was prepared via two steps of Michael addition reactions:(1) Michael addition reaction between 4,4’-methylenebis(2-methyl cyclohexyl amine) (Laromin C260) and excessive dialkyl maleates（DEF）; (2) The Michael addition reaction of the residual dialkyl maleates of step (1) with polyester polyamine Jeffamine D230. The two-steps method proposed could reduce the reaction time in comparison with the current one step Michael addition reaction method, thus satisfying the industrialized production. New PAE based polyureas were synthesized by reacting the PAE-f chain extender with aliphatic polyisocyanates 4,4’-diisocyanato dicyclohexylmethane (H₁₂MDI) / polyester polyamine Jeffamine D2000 prepolymer at room temperature. FT-IR and GPC were employed to characterize the new PAE prepared, and the morphology, molecular weight distribution and mechanical properties of the prepared PAE based polyureas were investigated by means of FT-IR and GPC. The FT-IR results indicated that the hydrogen bonding degree of amidogen groups in hard segments of the prepared polyureas were high, the length of hydrogen bonding were 0.305nm～0.306nm. The GPC experimental results show that the weight average molecular weight of the PAE-f based polyureas were 4.95×10⁴～6.05×10⁴,Mw/Mn were 1.65～1.97, the molecular weight distribution were relatively narrow. The mechanical properties demonstrated that the tensile strength were 14.7～22.5MPa, Elongation at break were 306～511%, Yang’s modulus were 67～127MPa, Shore A hardness were 64～83. The mechanical properties confirmed that the polyureas based on PAE-f were kinds of elastomeric materials with satisfied flexibility, strength, module and hardness.

Abstract: A reactive poly (ether ether ketone) PEEK with pendant propenyl groups was prepared by nucleophilic aromatic substitution of 4, 4’-Difluorobenzophenone (DFBP), diallylbisphenol A (DABPA) and bisphenyl A (BPA) as monomer. The prepared reactive PEEK with varying proportion was introduced to toughen bismaleimide (BMI) resin composing of 4,4'-bismaleimidodiphenyl methane (BMDM) and DABPA by melt technique without any solvent. The properties of the BMI resin as a function of the reactive PEEK concentration were evaluated. The presence of PEEK heightened the temperature of “ene” reaction for BMI and DABPA and slightly lowered the glass transition temperature (Tg) of the blends. The impact strength and fracture toughness were highest elevated from 9.0 KJ/m² and 186 J/m² to 15.2 KJ/m² and 239 J/m2 by 10 phr PEEK, respectively. At the same time, the thermal stability was improved by increasing the proportion of the PEEK. Scanning electron microscopy (SEM) of fracture surface revealed that the blends have good interfacial adhesion.

Abstract: Cellulose Oleate (CO) was synthesized by acylating cellulose in homogeneous system with p-toluenesulfonyl chloride (Tos-Cl) and oleic acid. The structure of CO was characterized by FT-IR, and degree of substitution (DS) of CO was determined by saponification method. Substituent distribution analysis was carried out with curve-fitting method, and the results indicated that acyl reaction of cellulose with oleic acid preferred to react at primary hydroxyl groups. The CO converted into films by casting. The mechanical properties of CO films were investigated. With the increase of DS, the tensile strength decreases gradually, but the tensile strain increases apparently.

Abstract: The rheological performance of konjac glucomannan (KGM) sol was investigated in alcohol/water solution, and the structure of KGM films were analyzed. The results showed that the dependent relation between the rheological properties and alcohol concentraiton, the viscosity increased with the concentration of alcohol increasing until the inflexion point of 11%. The results of KGM films analyzing indicated that alcohol promoted KGM film partially formed ordered layer arrangement, and the crystallinity gradually increased with the increase of alcohol concentration, then the transmittance and water absorption decrease.

Abstract: The Cu-Ni-Si-Mg alloy was treated by aging after varying cold deformation. The effect of cold deformation, aging temperature and aging time on the microstructure and properties of the alloy were investigated. The results indicate that the alloy produce a larger number of slip bands and dislocations after cold deformation, it can accelerate the precipitation of phase during aging, improve the microhardness and electrical conductivity. The microhardness and electrical conductivity of the alloy with 80% deformation aging at 723 K for 1h are 242HV and 35.53%IACS, respectively. The volume fraction of the precipitated phase was calculated by measuring the electrical conductivity of the alloy with 80% deformation aging at 773 K, then both the equations of phase transformation and the electrical conductivity equation were obtained.