This paper deals with the effect of a metallic salt treatment on the antibacterial activity of cellulosic fabrics against three kinds of bacteria: gram-positive bacteria Staphylococcus aureus (S. aureus), gram-negative bacteria Klebsiella pneumoniae (K. pneumoniae), and methicillin resistant Staphylococcus aureus (MRSA). Two kinds of cellulose fabrics are treated with the metallic salts CuSO4 and ZnSO4. The fabrics are pretreated with succinic acid anhydride to make adsorption of metallic salts more effective. This pretreatment is very effective at increasing the amount of metal ions adsorbed, and is more prominent in Cu ion than in Zn ion. The degree of antibacterial activity of samples treated with Cu salt against one of the S. aureus increases with an increasing amount of adsorbed Cu ion. A similar tendency is observed for the samples treated with Zn salt, although its correlation is not as clear as for Cu ion. Antibacterial activity is also confirmed against K. pneumoniae. The degree of antibacterial activity of samples treated with Cu salt against MRSA is almost independent of the amount of Cu ion adsorbed, and the tendency is similar for samples treated with Zn salt. After ten laundering cycles, the effect of the treatment is maintained. We conclude that these treatments are very effective in providing antibacterial activities to cellulose fabrics.

The origins of the thermal and mechanical properties of chitosan and poly(vinyl alcohol) (PVA) with inter-and intra-hydrogen bonds were investigated systematically by using X-ray, DSC, positron annihilation and viscoelastic measurements. Based on their individual properties, the characteristics of the blend films were estimated in relation to their morphology and mechanical properties as a function of chitosan content. The characteristics of the blend films were also analyzed in terms of the deviation from a simple additive rule of chitosan and PVA content. These results suggested that the miscibility of chitosan and PVA could be ensured by entanglement of the amorphous chain segments of chitosan and PVA. Further detailed analysis revealed that the chitosan content on the film surface is higher than that of the admixture content of chitosan after elongation, although the chitosan and PVA chains were crystallized independently. The elongation could be achieved for the blend films whose PVA content was higher than 50% and the drawn blend films were transparent. Thus, it may be expected that sufficiently entangled meshes formed between chitosan and PVA amorphous chains within the film, the PVA content being higher than 50%, were maintained under the elongation process.

ABSTRACT:The orientation of the three principal crystallographic axes, the a-, b-, and c-axes of crystallites of poly(ethylene terephthalate) (PET) under simultaneous biaxial stretching was estimated in terms of the orientation distribution function. For most of crystalline polymers with a triclinic unit like PET, there are no crystal planes perpendicular to the a-, b-, and c-axes that can be detected directly by X-Ray diffraction techniques. Accordingly, the functions of the a-, b-, and c-axes must be calculated by the method proposed by Roe and Krigbaum. In doing so, the orientation functions of the reciprocal lattice vectors must be measured for a number of crystal planes. In this paper, as an example, the orientation of crystallites and the orientation of the a-, b-, and c-axes were estimated for a PET film under simultaneous biaxial stretching in terms of the orientation distribution function of crystallites because of considerable utilization rate of PET as commercial films. The estimated orientation functions of the b-and c-axes predicted the detailed information concerning uniplanner orientation of benzene rings parallel to the film surface. [DOI 10.1295/polymj.36.394] KEY WORDS The Three Principal Crystallographic Axes / Poly(ethylene terephthalate) / Simultaneous Biaxial Stretching / Orientation Distribution Function of Crystallites / Benzene Rings / The evaluation concerning molecular orientation was first proposed by Herman in terms of the second order orientation factor.1 This factor is a sort of the second moment of the orientation function. After then, the orientation of crystallites was estimated by Roe and Krigbaum 2-4 in terms of the distribution function. The mathematical representation was given by an expansion of the distribution function in a series of generalized spherical harmonics. This method has been very important to obtain the orientation of the three principal crystallographic axes, the a-, b-, and c-axes, in terms of the orientation distribution function. Actually, there are several papers for estimating orientation distribution functions of the three principal crystallographic axes, the a-, b-, and c-axes of polyethylene, 5,6 poly(vinyl alcohol), 7,8 nylon 6 9 and cellulose. 10The first trial for poly(ethylene terephthalate) by Krigbaum and Balta 11 was done by using a simple uniaxially stretched films but their trial was absolutely unsuccessful. However, the recent development of computer program and high power X-Ray source provide easy peak separation of overlapped peaks and the orientation functions for the reciprocal lattice vectors can be obtained for a number of crystal planes with high accuracy. Consequently it becomes possible to calculate the orientation distribution functions of crystallites as well as of the a-, b-, and c-axes from the observed orientation functions of the reciprocal lattice vectors of the crystal planes. In previous paper, 12 the orientation of crystallites with a triclinic unit was evaluated in terms of orientation distribution function for a PBT fi...

ABSTRACT:Simultaneous biaxially stretching was carried out using ultra-high molecular weight polyethylene dry gel films which were prepared by crystallization from solutions. The concentrations were 0.45, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0 g/100 mL. The maximum draw ratio was dependent upon the concentration of the solutions. The greatest significant drawability could be realized at 0.9 g/100 mL which is much higher than the optimum concentration of 0.45 g/100 mL assuring the draw ratio > 300-fold for uniaxially stretching. Young's modulus of the biaxially stretched film was much lower than that ofuniaxial films with the same draw ratio (70-fold), although the Young's modulus of the film with the maximum draw ratio was much higher than that of commercial films. To address this problem, the orientation function of crystallites was determined from the orientation of the reciprocal lattice vectors of the crystal planes. As the result, it turned out that the c-and a-axes are oriented predominantly to the film surface but the orientational degree of the caxis is not remarkable in spite of high draw ratio of 8.7 X 8.7. The second order orientation factor was estimated from birefringence by subtracting the crystalline contribution from the total birefringence. These results indicated that the preferential orientation of the c-axis to the stretching direction is mainly due to the rotation of crystallites around their b-axis leading to straining of tie molecules. Furthermore, the ultimate value of Young's modulus was estimated by assuming an ideal simultaneous biaxially stretching film with 100% crystallinity and the perfect orientation of the c-axis parallel to the film surface. Even so, the predicted value was less than 10 GPa, when the elastic compliance of a crystal unit by Odajima and Zehnder were employed. This indicates the difficulty in producing high modulus and high strength polyethylene sheets in terms of theoretical aspects.