The three-dimension weft- knitted loop model was constructed using the simulated yarn which was made by mass-spring system. The simulated yarn was constructed with the cross-sections consisting of the mass-points connected by the springs within the mass-points. In the simulated yarn, two types of springs were used to describe tensile and bending behaviour of the model. The geometrical knitted loop structure was constructed by setting the cross-sections of the simulated yarn in the loop model considering with the loop parameters. The mechanical properties of the loop model under the tensile condition were expressed by using some formulae considering with the construction of the knitted structure.
Cotton cellulose is the most widely used natural polymers in various areas. Graft polymerization was attempted to introduce dyestuff onto cotton cellulose fiber for a trial on clean dyeing. A conventional free radical polymerization via UV initiation and a living radical polymerization via atom transfer radical polymerization method were used. Modified cationic dye with acrylic acid was grafted for coloring and an organosilane monomer was co-grafted for dye fixation. The chemical structure and morphology of grafted polymer of modified dye and organosilane were characterized. The color fastness and physical properties of grafted cotton cellulose were discussed. It is found that uniform organosilane film with moderate thickness formed via ATRP method was more beneficial to dye fixation with better color fastness. The original shape and typical convolutions of cotton fiber were reserved via ATRP method.
A study of the structure and morphology of polyurea-9, polyurea-10, and polyurea-11 crystals was conducted. For the quantitative analysis, these uniaxially drawn samples were examined using wide-angle X ray scattering (WAXS) measurements. The WAXS patterns of the polyurea films suggested a chain-packing configuration similar to that of polyamide crystals, which might indicate the trigonal lattice structure observed for polyamide-10, polyamide-11, polyamide-12. The diffractions of (001) and (002) were strongly dependent on the length of the aliphatic hydrocarbon of polyurea. In addition, we observed the occurrence of transitions from the α-form to the δ-form during heating, and that from the δ-form to the α-form during cooling with insitu synchrotron radiation WAXS measurements. The transitions were similar to the so-called Brill transition in polyamide or nylon films.