The statistical analysis and artificial neural networks were applied to the prediction of cotton yarn strength with fiber properties measured by an HVI instrument. The linear and non linear relationships between fiber properties and yarn strength were compared in the multiple regression analysis. The coefficients of correlation and determination as well as the adjusted coefficients of determination were calculated in order to select effective parameters among the various fiber properties. Neural networks with the back propagation learning algorithm were trained to match a set of input data with the corresponding set of output data, and their weights were obtained. The results obtained by the statistical analysis and neural networks were compared with each other in terms of the mean of square error between the target values and the experimental ones. It is therefore concluded that neural networks provide an effective tool alternative to the statistical method for yarn strength prediction and do not require a specific model necessary for the regression method.

Since the pyrolysis of polymers has continuous cycle, acrylonitrile (AN) was polymerized on the surface of the PET fabrics using an inductively coupled glow discharge system to promote crosslinking at the fabric surface to protect further pyrolysis. We investigated the flammability characteristic of plasma polymerized acrylonitrile (PPAN) deposited fabric, and dyeability. The chemical structure of PPAN was different from that of AN by molecular recombination, and the thermal analysis indicated that the PPAN was crosslinked. PPAN on the fabric results in a char which insulates the bulk from the heat of flame zone, and prevents the producing of flammable volatile fragment, and caused an increase in LOI value and decrease in burnins rate. Owing to the formation of unsaturated groups such as C=C and C=N and the second generation polar group C=0, dyeability of treated fabrics was improved.

The effects of surface treatment carried out to improve the spinnability and anti-static property of angora rabbit fibers were studied. Angora rabbit fibers were treated with a mixture of 0.5%(wt%) formic acid and 1.5%(wt%) hydrogen peroxide (1:1 v/v) for 60, 80 or 100 minutes at 40, 60 or 80 $^{\circ}C$. The effects of treatment time and temperature on the surface structure, tenacity, elongation, tensile modulus and surface resistance were investigated. Scales of the cuticle layer were effectively raised without lowering the tenacity when treated for 80 minutes that of the untreated. The tenacity and the tensile modulus decreased slightly with the increase of treatment time and temperature, while the elongation and the surface resistance increased markedly. It should be noted that the influence of treatment temperature on the decrease in surface resistance of the treated fibers is more significant than that of treatment time.

Six aminoazobenzene disperse dyes derived from different N,N-dialkylanilines and 2-chloro-4-nitroaniline, were synthesized and their chemical structure were analyzed by 500 MHz NMR spectroscopy. The wavelength of maximum absorption of the synthesized dyes, which was dependent on the electron donating ability of the substituent, was in the range of 517.5~531.0 nm. As terminal alkyl group had more carbon, the dyeing rate of disperse dye decreased, the exhaustion rate became lower, and wash fastness of the dyed fabric improved. These results were discussed in terms of the molecular volume of the dispose dye and dye-fiber interaction such as van der Waals force.

Mordant dyeing method was applied for good levellness and colourfastness in dyeing of nylon microfibre nonwoven fabric. Optimum mordanting conditions such as exhaustion time srior to chroming, chroming time, and temperature were determined. The optimum conditions obtained in this study were exhaustion for 30 minutes before adding chroming agent, adding caroming agent at 80 $^{\circ}C$ and chroming for 40 minutes. Wash fastness of nylon nonwoven fabric dyed with mordant dyes was better than that of the fabric dyed with metal complex dyes. Rubbing and perspiration fastness of the fabrics dyed with mordant dyes were satisfactory as well.

The phenolic carbon matrix precursor was modified by adding pitch and graphite powders. The carbon yield measured both from thermogravimetric analysis and normal carbonization process increased as the powder content increased. The carbon yield from the normal carbonization process has resulted higher value due to the slower heating rate. The bulk densities of c/c composites made from different matrix systems were in the range of 1.35~1.41 g/㎤. From 3-point bending test, the effect of matrix modification was confirmed with the changes in the mechanical properties of the greenbody. As the powder content increases, the mechanical properties of greenbody deteriorated. However, after carbonization the mechanical properties of the c/c composites made from the modified resin with pitch and graphite powder showed higher value than those of the c/c composites made with non-modified phenolic matrix precursor.

Poly(amirs dialkyl ester) precursors of high performance polyimides were synthesized by employing the direct polymerization method using phenylphosphonic dichloride as an activating agent and pyridine as a Lewis base. Their thermal imidization behavior was investigated by performing both isothermal and nonisothermal TGA(thermogravimetric analysis) experiments. The precursor polymers showed a two-stage imidization behavior, i.e., fast imidization at the early stage and slow imidization at the later stage. In our studies, the kinetic data obtained at the early stage were chosen to determine the rate constants. Kinetic data were interpreted using the first order kinetic plot of the logarithmic wt % loss versus time. The observed imidization behavior was interpreted in view of the length of alkyl leaving group, chemical reactivity and the mobilitl of polymer backbones.

A new method for the estimation of the initial portion of the crystallization exotherm, normally obscured due to the response time of the DSC in the case of fast crystallization, was developed. This method allowed a more accurate analysis of the DSC isothermal crystallization data. Poly(propylene glycol)(PPG)-poly($\varepsilon$-caprolactam) (PCL)-PPG triblock copolymers with various PPG contents were synthesized via anionic copolymerization of $\varepsilon$-cairo-lactam and the macroactivators which contain PPG units. Isothermal crystallization behaviors of the synthesized block copolymers were allalyzed with Avrami equation by using above-mentinned non-linear curve fitting program and conventional Avraml plot. At PPG contents greater than 10%, the overall crystallization rate decreased because of the uncrystallizable PPG unit. The induction time for crystallization increased, and the ratio of primary crystallization to overall crystallization increased at the same degree of undercooling. On the other hand, crystal growth rate increased with PPG content. The presence of PPG unit in the block copolymer has two opposing effects on crystallization. First, as the amount of PPG unit increases it interferes with nucleation. As a result the induction time for crystallization increases and the crystallization rate decreases. Secondly, it increases the mobility of the block copolymers because of the ether linkage and allows faster diffion of the copolymer chain to the crystal surface. Consequently the crystal growth rate after nucleation increases. Between the two effects the first one seems to be dominating and the overall crystallization rate decreases with increasing PPG content in block copolymers. Furthermore there are some different crystallization behaviors between the block copolymers and PCL homo polymer. Nucleation of block copolymers of PPG content up to 10% occurs faster than in the case of homo PCL because small amounts of PPG unit may act as heterogeneous nuclei. Also the chain mobility increased with the introduction of PPG unit, therefore the overall crystallization rate was faster than homo PCL. But if the PPG content exceeds 10% the overall crystallization rate of the block copolymers becomes slower than homo PCL.

Two-component polyurethane coatings were prepared by blending benzoic acid poIycaprolactone modified polyester polyol (BZAOs), synthesized with components of adipic acid/1,4-butanediol/polycaprolactone/bensoic acid, and polyisocyanate (TDI- adduct). Kinematic viscosity of BZAO was gradully decreased with increasing benzoic acid content in BZAO. The kinematic viscosity of modified polyesters are decreased as the benzoic acid content increases. After the film was coated with the prepared polyurethane coatings, the various physical properties were measured. They showed drying time of 4~6 hour and pot-life time of 15~27 hour, so they were proved to be coatings with long pot-life time. They showed good physical properties such as flexibility, impact resistance, cross hatch adhesion, and rust resistance. These advantages are the results of introducing polycaprolactone polyol.ram and conventional Avraml plot. At PPG contents greater than 10%, the overall crystallization rate decreased because of the uncrystallizable PPG unit. The induction time for crystallization increased, and the ratio of primary crystallization to overall crystallization increased at the same degree of undercooling. On the other hand, crystal growth rate increased with PPG content. The presence of PPG unit in the block copolymer has two opposing effects on crystallization. First, as the amount of PPG unit increases it interferes with nucleation. As a result the induction time for crystallization increases and the crystallization rate decreases. Secondly, it increases the mobility of the block copolymers because of the ether linkage and allows faster diffion of the copolymer chain to the crystal surface. Consequently the crystal growth rate after nucleation increases. Between the two effects the first one seems to be dominating and the overall crystallization rate decreases with increasing PPG content in block copolymers. Furthermore there are some different crystallization behaviors between the block copolymers and PCL homo polymer. Nucleation of block copolymers of PPG content up to 10% occurs faster than in the case of homo PCL because small amounts of PPG unit may act as heterogeneous nuclei. Also the chain mobility increased with the introduction of PPG unit, therefore the overall crystallization rate was faster than homo PCL. But if the PPG content exceeds 10% the overall crystallization rate of the block copolymers becomes slower than homo PCL.

The purpose of this work is to set up design conditions of picking mechanisms in rapier looms. For this purpose, various kinds of picking mechanisms are surveyed during the study with a special emphasis on what kind of functions are required for a successful picking process and on how these functions are realized in each of the picking mechanism investigated. Based on the observations, two basic functions that must be accomplished by a picking mechanism are identified. Finally, the design conditions are utilized in evaluating the surveyed picking mechanisms with the help of the axiomatic design approach.