The ferroelectric phase transition was investigated in the blends of vinylidenefluoridetetrafluoroethylene (VDF-TFE) and vinylidenefluoride-hexafluoroacetone(VDF-HFA) copoly-mers using X-ray diffraction, infrared spectroscopic and differential scanning measurements. All the samples prepared except pure VDF-HFA copolymer showed the ferroelectric transition well. The ferroelectric-paraelectric phase transition temperature was over a broad temperature range and complete transition finished with its melting. The transition from ferroelectric phase to paraelectric seemed to occur without passing through the intermediate phase which was shown in vinylidenefluoride-trifluoroethylene copolymer. The paraelectric-ferroelectric phase transition of blends was found only at a cooling rate less than at least 5˚C/min from the melt and this transition was due to that of VDF-TFE copolymer because of crystallization behavior in the blends.

In this study, preparation of new chelating resins hearing dihydroxamic acid groups and the adsorptive ability for heavy metal ions are described. The various types of the macroporous polychloromethylstyrene(PCMS) resin matrix were firstly synthesized by polymerizing chloromethylstyrene(CMS) with divinylbenzene or ethylene-glycol dimethacrylate. PCMS was treated with diethylmalonate in N, N'-dimethylformamide to give the resin having diethylmalonate groups. These resins were then treated with hydroxylamine in methanol to afford the dihydroxamic acid resin. The dihydroxamic acid polymer contained carboxylic acid groups as well as hydroxa-mic acid ones. The polymer showed an excellent adsorption capacity for uranium ions.

PET/nylon 6 blends were prepared in the presence of p-toluenesulfonic acid (TsOH) and analyzed by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray diffraction (XD). As ester-amide interchange reaction proceeds, Tm of each component in the blends was decreased and crystallization temperature on cooling was increased. Especially, Tm of nylon 6 component was decreased more rapidly than that of PET component with the increase of blending time. This finding is explained by the reduction of hydrogen bonding interaction of nylon 6 resulting from interchange reaction. SEM observation and XD analysis showed that miscibility was increased with the progress of inter-chain reaction.

In order to explore the piezoelectric mechanism of the poly(vinylidene fluoride) (PVDF) film, the true piezoelectric constant was expressed in terms of a combination of measurable mechanical and piezoelectric constant values. Each piezoelectric constant was divided into four subgroups according to their boundary conditions and then their interrelations were derived. In addition, the values of piezoelectric constants by the dimensional effect only were calculated. Thus, if we determine the ten constants of piezoelectric film, we can reveal the contribution of the dimensional effect in the piezoelectric mechanism.

In order to elucidate the coagulation mechanism for the polyacrylonitrile/HNO₃ (solvent)/H₂0(nonsolvent) wet-spinning system, the effects of the coagulation bath temperature and composition (content of solvent m the bath) on the coagulation behavior, and hence structure and properties of the resulting(proto and drawn) fibers have been investigated prior to finding out the optimum(critical) bath composition. Apparent diffusion coefficients of solvent at different coagulation conditions have been estimated from diffusing-out experiments during the coagulation step using Takeda's simplified model based on quasi-binary, equimolar diffusion. The changes in structure and properties of the fibers caused by the variation of the diffusion coefficient at different coagulation conditions have been confirmed from the experiments on mechanical properties, dye sorption, and morphological structure of the fibers.

The objective of this research is to develop the CAD system package used for digitized pattern designs and nesting, based on the mathematical and computational principles. In the pattern generation step, the digitizer is used for completed pattern input and the patterns information is defined such as family, name, size, loop, notch, hole, grading rule and etc. First of all, the geometric and alphanumeric data are defined, and then Qubic Bezier Curve is used in order to obtain the 2-dimensional smooth curve. So all of the pattern information organize the pattern database. After accomplished the step of the drafting patterns, this CAD package coverts the pattern data into the grid pattern data, which organizies the grid-pattern database. So in this research, the grid algorithm is developed. Using the grid algorithm, the overlapping between the patterns is easily protected. The transformation sub-programs easily support the nesting process, used to change the image on the display screen and to reposition the items in the pattern data base. This sub-program, which is applied to the pattern data in order to nest the minimum arrangement, is composed of translation, magnification, reduction, rutation and separation. Therefore, this CAD system package is the total procedures by which the sequence of processing steps to involve drafting clothing patterns, modifications, grading and nesting is planed and carried out. In the operation of this CAD package by the user, every programs is mutually joined.