Advanced Materials Research Vols. 554-556

Abstract: N-alkyl poly(p-phenylene terephthalamide)s (PPTA) is synthesized from PPTA and bromoalkane via metalation process in a solution of potassium methylsulfinylcarbanion in dimethyl sulfoxide. The modified PPTAs have been dissolved in conventional solvents, such as THF and CHCl3. The effects of substituted alkyl, substitution degree and inherent viscosity of PPTA on the solubility of N-alkyl PPTA were discussed. The substitution degree is calculated by FTIR and NMR. The molecular weight and distribution of N-alkyl PPTA has been obtained by GPC. The thermal properties are also discussed.

Abstract: Two phosphorus-containing flame retardant (FR) were synthesized and incorporated in the backbone of polyamide 6(PA6) by polymerization. The structure and spectroscopic data of these flame retardant were determined by Fourier Transform Infrared Spectroscopy (FTIR) and Elemental analysis. Flame-retardancy and thermal property of PA6 modified with CEP, and MMP were examined by LOI and TGA. The LOI value of PA6 shows ascending trend by adding FRs, and it rise from 24 to 31%. TGA data revealed that FR improves thermal stability of PA6. The on-set temperature was added at least 20°C.

Abstract: Taking polyether dihydroxy alcohol, toluene diisocyanate (TDI) and dimethylolpr- opionic acid (DMPA) as raw materials, aromatic polyether waterborne polyurethane emulsion was synthesized. And then the effects of isocyanate/macroglycol molar ratio(R value), amount of DMPA, neutral degree and temperature on the properties of emulsion such as appearance, viscosity, water absorption and stability were studied. The experimental results showed that when R value is 2~2.5, amount of DMPA used is 5.0%, reaction temperature is 80°C and neutral temperature is 40°C, the waterborne polyurethane emulsion synthesized meet the requirement of printing ink.

Abstract: The elastic recovery property of a novel poly(ester-imide-ether) (PEIE) was prepared from the 1, 4-butanediol (BD), poly(tetramethylene glycol) (PTMG1000) and imide dicarboxylic acid based on 1, 2, 4-benzenetricarboxylic (TMA) and aminobenzoic acid (PABA) was studied. The elastic recovery of the PEIE was studied in the fiber form. The influences of the draw ratio, temperature and heat treatment on elastic recovery were investigated. The results show that the novel PEIE possesses the excellent elastic recovery at low temperature and the quickly-changed temperature is lower than that of traditional poly(ester-ether)s. Meanwhile, the heat treatment process can improve the elastic recovery of the PEIE because this process improves the crystallization of the hard segments.

Abstract: A series of different generation hyperbranched polyurethane(HBPU) was synthesized based on the raw materials of isophorone diisocyanate(IPDI) and diethanolamine(DEOA). Their structure, thermal degradation mechanism and glass transition temperature(Tg) were characterized by fourier transform infrared spectroscopy(FTIR), nuclear magnetic resonance spectroscopy(NMR), thermal gravimetric analysis(TGA) and differential scanning calorimetry(DSC). The results showed that: the yield of each generation HBPU was up to 90%, different generation HBPU had almost the same initial degradation temperature(about at 200°C) and they all had two decomposition platforms; with the increase of generation, Tg increased from 107.2°C to 132.1°C. The gloss and hardness of the HBPU coatings were significantly improved.

Abstract: Taking L-Lysine Diisocyanate (LDI) as hard segments, poly-ε-caprolactone diol (PCL) as soft segments, a kind of nontoxic and biodegradable waterborne polyurethanes were synthesized using two-step polymerization. And then the effects of isocyanate/macroglycol molar ratio(NCO/OH, R value), the 1,4-butylene glycol (BDO) content and prepolymerization temperature on the properties of waterborne polyurethanes were investigated. The experimental results showed that when R value is 1.5, the BDO content used is 4% and the reaction temperature is 80°C, the products prepared were best in application. The mechanical property tests showed that it has good mechanical properties, tensile strength is up to 46.5MPa and the loss amounts of the hydrolytic degradation after 80 days is 42%. The waterborne polyurethanes prepared have excellent biodegradability, which can be widely used as a biological medical material.

Abstract: As social civilization advances, more and more people reside in the city. Consequently, the number of automobiles and locomotives increases, causing greenhouse effect and noise pollution increasingly serious. Therefore, lowering the temperature and reducing the noise in living conditions has become an urgent task, in order to save resources usage amount and to produce a low-noise dwelling environment. In this study, the sound-absorption and heat-insulation nonwoven fabrics were firstly prepared by three-dimensional crimp hollow polyester fiber (PET) fibers and Polypropylene (PP) fibers based on nonwoven processing technology, following by sound-absorption coefficient test, thermal conductivity test, as well as maximum tensile strength and maximum tearing strength tests. The results show that, 70/30 wt% PET/ PP nonwoven fabrics have the maximum tensile strength of 2.47 MPa (CD) and 1.67 MPa (MD), in addition with the maximum tearing strength of 83.96 kN/m (CD), 111.88 kN/m (MD); the 90/10 wt% PET/ PP nonwoven presents the lowest thermal conductivity coefficient of 0.0365 W/K‧m; nonwoven with three different ratios show the similar sound-absorbing curves, which all reaches the highest absorption coefficient of 0.76 at 4000 Hz.

Abstract: According to the corresponding national standard methods, the surface tension, HLB value, CMC value and emulsification performance of the product were determined. Compare the hydrolytic stability with other three kinds of organic silicon surfactants, the experiment result shows that the hydrolytic stability of product is better than the similar products. The key to reduce the hydrolysis rate of polyether modified polysiloxane surfactant is to reduce the contact of polysiloxane chain in surfactant molecules with water solution. For methoxy-terminated polyether modified polysiloxane, the methyl ether open as the umbrella, which can reduce the contact of polysiloxane chain in surfactant molecules and water solution to a certain extent, so the hydrolysis stability raise.

Abstract: Polyphenylene sulfide (PPS) is considered as a high performance thermoplastic material and to be used in many areas, but the application of PPS used as protective clothing is limited because it is difficulties to be dyed and finished. In this work the effects of benzyl benzoate as a carrier on the structure and performance of PPS especially dyeability were evaluated. The glass transition temperature, crystalline structure and orientation degree of treated PPS fiber with benzyl benzoate were investigated by differential scanning calorimetry (DSC), X-ray diffraction analysis and velocity-oriented tester. Adsorption thermodynamic and kinetic study of disperse dye on PPS treated with carrier was carried out under the condition of pH value 5, initial dye concentration 0.01–0.5 g/L and liquor ratio 1,000:1. The results indicated that benzyl benzoate, as a dyeing carrier, could reduce the glass transition temperature and orientation degree of treated PPS fiber. The benzyl benzoate could improve the standard affinity, diffusion coefficient and the equilibrium dyeing rate of disperse dye on PPS fiber, while the decrease of tensile strength was very little.

Abstract: A new prepolymer of polyurethane acrylate (PUA) was synthesized from cyclohexanone- formaldehyde resin (CFR) with high hydroxyl value, toluene diisocyanate (TDI) and 2-hydroxyethyl methacrylate (HEMA) by using dibutyltion dilaurate as catalyst via two steps. The result from Fourier transform infrared spectrum (FT-IR) showed that methacrylate group was introduced into the terminal of CFR by using TDI as bridge and curable PUA was obtained. Then, the PUA was cured by using azodiisobutyronitrile as catalyst at 110-130°C for 2h. The resulting product has excellent solvent resistance.