In the present paper, the synthesis and imidization kinetic studies of polyamic acid esters have been made. Pyromellitic dianhydride (PMDA) diester monomers have been synthesized from the ring-opening reaction of PMDA and aliphatic alcohols such as methanol, ethanol, isopropanol, n-butanol, t-butanol, and 2-hydroxyethyl methacrylate. Polyamic acid esters have been synthesized from the direct polycondesation of 4,4'-oxydianiline and PMDA based diester monomers at room temperature using dicyclohexyl carbodiimide (DCC) or diphenyl (2,3-dihydro-2-thioxo-3-benzoxazolyl)-phos-phonate (DTBP) as an activation agent. When DCC was used as the activating agent. low molecular weight polyamic acid esters that are soluble in methanol were obtained. When DTBP was employed, however, high molecular weight polyamic acid esters whose inherent viscosity values were larger than 0.3 dl/g were synthesized. Furthermore. imidization kinetics of polyamic acid esters were studied by performing the dynamic thermogravimetric analysis (TGA) at a constant heating rate of 10℃/min. The activation energy and Arrhenius pre-exponential factor were calculated from the TGA thermograms. The imidization of polyamic acid esters was effected by the chemical structure of the diester monomers such as the size and bulkiness of alkyl groups of the diester monomers. Activation energy values for the imidization reaction increased from 83 KJ/mol to 169 KJ/mol with decreasing the size of the alkyl groups of polyamic acid esters.

Polyhydroxyamides derivatized with alkyl ester groups were investigated as possible candidates for new heat-resistant fiber materials which could be converted to polybenzoxazoles under fire conditions. Model compounds for these polyhydroxyamides were synthesized and their cyclization chemistry was investigated. The model compound study revealed that all the alkyl ester group containing model compounds could cyclize on heating. The rates of cyclization were dependent upon the structures of substituents. The longer and the larger the substituent, the faster was the rate of cyclization. The polyhydroxyamides showed similar results, namely, polyhydroxyamide derivatized with a longer or larger alkyl substituent showed a faster cyclization rate.

The effects of transesterification and blend composition on the physical properties of drawn PEN/PET blend fibers were investigated. Tensile strength and modulus of PEN/PET blend fibers were increased with increasing PEN content. The X-ray diffraction patterns of blend fibers exhibited less structure development compared with PEN or PET homopolymer fibers. The transesterification reaction leads to a miscible amorphous phase with the result that all blend fibers exhibit a single glass transition temperature between those of the two homopolymers. After drawing and annealing, PET or PEN homopolymer fibers exhibited higher degree of orientation-induced crystallization than PEN/PET blend fibers.

Air textured yarn(ATY) samples were prepared from hollow PET 75/24(SDY) and PET 100/192(SDY) under the different air pressures(6 bar~12 bar) and interlaced yarn(ITY) samples were prepared from hollow PET 75/24(POY) and PET HS 40/24 under the different air pressures(3 bar~6 bar) and two speeds(400 and 450 m/min) to determine their hollowness and physical properties. Measured physical properties included unit weight, tenacity, elongation, and dry and wet shrinkage. The important results of this study were: 1) The hollowness of ATY samples decreased with increasing air pressure. The hollowness decreased to 27% when the air pressure increased from 6 bar to 12 bar and the rate of decrease was most noticeable above 9 bar. In addition, the unit weight of samples increased with the air pressure and the rate of increase was most noticeable above 8 bar. However, there was little effect of air pressure on the physical properties. 2) The hollowness of ITY samples decreased with increasing the air pressure. The hollowness decreased to about 34% when the air pressure increased from 3 bar to 6 bar and the rate of increase was most noticeable above 4 bar. The number of entanglement of the samples increased with the air pressure. However, there was little effect of the air pressure on the physical properties.

An environmentally friendly artificial suede manufacturing procedure is established to improve the working condition, to lower the manufacturing cost and to make quality control easier. It binds fibers through hot melt pressing of PEE microfibers in the CDP/PEE islands-in-a-sea fiber eliminating the conventional manufacturing processes such as polyurethane impregnation, PVA treatment and slicing. The dyeing characteristic of multi-layered suede, whose K/S value was 12.4, was superior to the reference suede (K/S value: 9.6). Dyeing fastness of the nonwoven was generally superior to that of the reference suede. Especially wet abrasion and thermomigration were 1~2 grade higher than those .of the reference suede. The specifications of the environmentally friendly artificial suede after finishing were: weight; 190 g/$m^2$, thickness; 0.62 mm, fibrous density; 0.32 g/$\textrm{cm}^2$. It was lighter, thinner and more denser than those of the reference suede. The tensile strength, the tearing strength and the stretch recovery rate were comparable to the reference or a little better; the stiffness, the drape property and the anti-abrasion were excellent; the elongation and the compression recovery rate were somewhat unsatisfactory.

A method to manufacture aluminium(Al) fiber using powder extrusion technology and its nonwoven fabric was investigated. The fiber diameter(d) was determined by Al powder diameter(D) and extrusion ratio(ER). A good correlation between theoretical equation, d=1.15D/$(ER)^{1/2}$ and experimental value was obtained. The sub-micron scale Al fiber was also made by repeated extrusion. Two different bonding techniques, i.e., sintering and inorganic additive bonding methods were empolyed. For the production of Al nonwoven fabric, the latter method has many advantages, including lower process temperature, process simplicity, and productivity. Unlike the general characteristics of nonwoven fabrics produced by conventional bonding processes, the mechanical property of Al nonwoven fabric was relatively low. To enhance the property, the modification of web carding and bonding system is necessary.

This research is aimed at investigating torsional properties of two-ply wool yarn after waxing and heat setting. The properties of yarn in weft knitted fabrics influence post-processes such as knitting, dyeing, and finishing. Therefore, pre-treatments of the knitting yarn are required to exclude negative factors in these processes. In this paper two treatments were studied; one was waxing carried out to reduce friction in the knitting process, and the other was heat setting carried out to reduce residual torque. Torque, snarling tendency, and coefficient of friction were analyzed to investigate the effects of waxing, heat setting, or waxing after heat setting. Torque and coefficients of friction decrease and snarling is not significantly changed after waxing. Also, snarling of yarns decreases apparently on heat setting.

In this study, the frictional properties between geotextiles and geomembranes were estimated for utilization in the design of waste landfill systems. The shear stress at three different types of shear rates and each normal stress were evaluated by direct shear test. All eight geomembrane/geotextile interfaces showed post-peak reductions in shear strength and similar stress-strain curve patterns regardless of the type of materials. These post-peak strength reductions were apparently the polishing effects on the geomembrane surface. The shear rate showed no significant effects on the shear strength in each geosynthetic interface regardless of the type of geotextiles. The shear strength between geosynthetics interfaces increased proportional to the increasing normal stress. The parameters influencing the interface frictional properties between geomembrane and geotextile were the fiber length and type and the fiber diameter. The filament type in nonwoven geotextile exhibited higher frictional forces than other geotextiles.

Collision behavior of TPU(thermoplastic polyurethane elastomer) airbags were analyzed using two and three dimensional numerical methods to understand the effects of process parameters such as internal pressure, material properties, speed of air leakage on collision performance. The analysis results were also compared with experimental results. The internal pressure was confirmed to affect the collision performance significantly, as it increases to a certain degree showing favorable contribution. Also, air leakage was considered in order to further enhance the collision behavior.

The purpose of this study is to examine the influence of an acidic cellulase treatment on the properties of four kinds of cellulosic fabrics including cotton, viscose rayon, and their carboxymethyl derivatives. The degree of substitution of the carboxymethyl derivatives of cotton and rayon were 0.11 and 0.20, respectively. Weight loss after the enzyme treatment was in the following order: CM-cotton>cotton>CM-rayon>rayon. All treated fabrics had higher moisture regain, water retention value and air permeability, while tensile strength decreased after the treatment. Cellulase treated rayon and CM-rayon fabrics were more flexible than cellulase treated cotton and CM-cotton fabrics. Additionally the CMC treated fabrics were slightly whitened by the enzyme treatment.

Starch films plasticized with glycerol(weight ratio of starch to glycerol=10:3) were prepared by casting and were subsequently coated with polyurethane(PU) synthesized from castor oil and tolylene diisocyanate(TDI). The coating process was performed using a motor-driven dip-coater and thickness of coated layers was 5~23${\mu}{\textrm}{m}$. The coated layers were stabilized by covalent bonds between excess isocyanate groups of PU and hydroxyl groups of starch films, proved by FT-IR, DSC, and SEM. The effects of PU-coating on water-sorption behavior and mechanical properties of the films were investigated. The flexibility of uncoated films increased with relative humidity(R.H.), however, mechanical properties such as elastic modulus and tensile strength decreased significantly, due to the plasticizing effects of glycerol and water at ambient temperature. Overall absorption/desorption behavior of the coated films under different R.H. conditions was similar to that of uncoated film, whereas sorption rate and amount of sorbed water decreased with increasing coating thickness. In addition, elastic modulus and tensile strength of the coated films increased with thickness of the coated layers in the R.H. ranges investigated when compared with the uncoated films. Therefore, it could be concluded that the water-proof and mechanical properties of starch films were improved by PU-coating.

As a part of the study of "overseas-brand" and "domestic" apparel inventory control strategies utilising computer simulation. the work conducted in this paper is concerned with the investigation of one of the case study apparel organisations, company B, supplied with locally manufactured products in South Korea (refer to the "overseas-brand" apparel entrepreneur, company A, in part 1). The aim of the research was to explore the issues associated with the production and distribution of apparel products to improve the understanding of the interrelation of domestic apparel production-distribution system factors. The goal to develop the optimum inventory control strategies for domestic apparel companies was achieved by the use of a computer simulation model developed based on the specific apparel supply chain environment. The data derived from the two, selected case study companies' activities can be referred to in the previous studies [1-3], that also explained the development of a computer simulation model of apparel production-distribution strategies and the application of simulation to the selected overseas-brand garment inventory control strategies. In this paper, the key production-distribution functions, e.g. the "domestic" company's stock level control strategies were examined within the simulation model developed to determine optimum strategies by exploring the interactions of the defined apparel production-distribution parameters and their relative contributions within the given system. The experiments further demonstrated the benefits of the simulation models to devise strategies to improve the apparel inventory control as well as the production-distribution chain control performance. As the dominant factor within the total costs was the product cost (refer to appendix 1), maximising gross margins was critically dependent on ordering and re-ordering appropriate product quantity to maintain service levels while monitoring the stock level not too much to incur excess costs.