Advanced Materials Research Vols. 332-334

Abstract: In order to find out the variation law of ink stickiness during the printing, the ink tack value under 9 different linear velocities of ink distributing roller was tested, and the relation equations between tack value and the roller linear velocity were built up. At the same time, the plastic viscosities of 8 offset inks and their tack values under 9 separation velocities were also tested. The study results showed that the higher the linear speed was, the larger the tack value was, and it would stay in a relatively high tack value (regarded as infinite tack value). Also, the printing ink having high viscosity may possess low tack value.

Abstract: Through the earlier accelerated aging tests (oven aging) of Nylon 66 yarns used in automobile airbags at the temperatures ranging from 60°C to 150°C, we have established a dynamics equation of tensile strength and aging time, and predicted the storage lifetime of this material in 25°C based on Arrhenius methodology and extrapolation method. Besides, the activation energy and thermal-oxidative aging parameter of Nylon 66 have been worked out from the test results. The study has showed that Nylon 66 airbag material has great thermal stability at high temperatures, and its storage lifetime under normal temperature is 4 times of its expected lifetime by design. The prediction results can be referenced for planning the service life of SRS or selecting airbag fabrics.

Abstract: A series of novel conducting nanocomposite (NC) hydrogels, poly(N-isopropylacrylamide) /Clay/MWNT, were synthesized by in situ free-radical polymerization. The chemical structure of the gels was characterized by Fourier transform infrared spectroscopy (FTIR). The temperature responsive behaviors and mechanical properties were also investigated in detail. The prepared NC gels presented a rising volume phase transition temperature (VPTT) and enhanced mechanical properties. When the water content reached 700%, the conductivity increased from 0.46 to 1.09 ms•cm^-1 with the addition of MWNTs increasing from 0 to 1.19wt%. The improved mechanical strength and conductivity make the NC gels a potential material in the development of artificial muscles, biosensors, bioseparation and other advanced materials both academically and practically.

Abstract: Antheraea pernyi silk fibroin (ASF) solution was prepared by dissolving Antheraea pernyi silk fiber in lithium thiocyanate solution. The ASF/1,4-butanediol (ASF/BDO) blend porous materials were prepared with freeze-drying method. The structure of ASF was investigated by the X-ray diffraction method. The result showed that the structure of regenerated ASF scaffold was α-helix and random coil conformation. After ASF mixed with 5 wt% BDO, the structure of ASF was changed to β-sheet and the ASF scaffolds became water-insoluble. There were some small pores and fibrous structure in the big pores and the surface of pores was rough with a great many raised particles. The scaffolds with the average pore size of 300-1000μm and the porosity of 82-92% can efficiently be produced in this paper. Due to avoid the use of organic solvents or harsh chemicals, these new ASF based porous materials provide much more excellent biocompatibility and is expected to be applied to tissue regeneration scaffolds.

Abstract: Two kinds of imide dicarboxylic acid monomers, 4,4'-bis(trimellitimido) diphenyl ether Ⅰ and p-trimellitimido-benzoic acid Ⅱ were successfully synthesized from 4,4'-diaminodiphenyl ether and p-aminobenzoic acid with trimellitic anhydride respectively.and used to synthesize a series of new aromatic poly(amide-imide)s (PAIs) by the tri-phenyl phosphite-activated polycondensation method. The preparation of PAIs was carried out using triphenyl phosphate and pyridine symtem. The PAIs had inherent viscosities of 0.55–1.46 dL g-1. PAI films were obtained by casting their N-Methyl-2-pyrrolidone (NMP) solution. Their cast films had tensile strengths ranging from 37.4 to 83.9 MPa. The glass-transition temperatures (measured by differential scanning calorimetry) were in the range of 265-310°C. According to thermogravimetric analysis, the polymers were fairly stable up to temperature around 420°C, and 10% weight losses in the temperature range of 474-550°C in nitrogen, that showed good thermal stabilities of these polymers.

Abstract: Rabbit hair is a kind of animal hair, containing a large amount of keratin which can be extracted. According to the preparation method of wool protein powder, rabbit hair powder was obtained, and the morphology of the protein powder was observed by microscopy. By reacting with the alkali solution, two kinds of protein powders which were prepared from rabbit hair and wool, were used in modification of polyester fabric. Experimental results showed that samples with rabbit hair protein powder has evident improvement in moisture absorption of polyester fabric compared with untreated and wool powder treated samples, while UV protective properties of sample treated by rabbit hair powder was unexpected decreased, a further investigation will carry out to explain it.

Abstract: Design of antibacterial woven fabrics was discussed in view of visual impact and antibacterial activity. Antibacterial yarns can be obtained from blending and combining of silver-coated fibers. Analysis of manufacturing process and cost shows that core-spinning and sirofil spinning are preferable. Core-spun yarns can be used in filling if silver color is not desired. If silver color is desirable, sirofil yarns can be spaced at regular intervals in filling direction.

Abstract: Large single crystal of Na2Ni (SO4)2.4H2O (NNSH) was grown for the first time using method of isothermal decrease of supersaturation. The crystal structure of NNSH is determined by single crystal X-ray diffraction method, which is far different from the structure of known nickel sulfate hexahydrate series compounds. The growth habit, optical transmission spectrum and thermal stability are first reported in this paper. Similar optical transmission spectrum with nickel sulfate hexahydrate (NSH) crystal shows that NNSH crystal can also been used as ultraviolet light filter (ULF). The dehydration temperature (tdh) is 132º, which is much higher than commercial available ultraviolet filters, this is correlate with the unique crystal structure of NNSH crystal.

Abstract: A novel chitosan/poly(vinyl alcohol) composite packaging films were prepared by the casting method, and the effects of chitosan concentration on the structures, mechanical properties, permeability for oxygen and water vapor were discussed in this study. Mechanical properties of these films, which were evaluated by the tensile test and the barrier properties showed that the elongation at break (E) of the composite films decreased rapidly with the addition of chitosan, whereas, the tensile strength (TS) presented an almost opposite trend. Both the water vapour and oxygen transmission rate values were increased with the increasing amount of the chitosan in the composite films. Based on the obtained results, the better property of the composites films would be prepared chitosan/poly(vinyl alcohol) blends at a weight ratio of 3/5, and the tensile strength and elongation at break of the packaging films were 34.12 MPa, 40.24 % respectively. It was also observed that the water vapor permeability coefficient (Pv) and the oxygen permeability coefficient (P) of chitosan/poly(vinyl alcohol) composite packaging films prepared with weight ratio of 3/5 were 1.99×10-15 g•cm/cm2•s•Pa and 7.98×10-16 cm3•cm/cm2•s•Pa respectively. The composite films in this paper can be used in fresh-keeping or other fields as a kind of green packaging material.

Abstract: The major indoor air pollution-formaldehyde has been a serious threat to our lives to our lives, and accordingly the formaldehyde degradation has turned into a concerned issue of public. This paper has based on a number of degradation methods and combined the adsorption effect of activated carbon with the catalytic effect of MnO₂ to remove formaldehyde. The results show that the Nano-MnO₂ particles loaded the surface of activated carbon particles possesses smaller sizes, better dispersion and no agglomeration, and consequently the AC/MnO₂ compounds degraded formaldehyde effectively.