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Based on some assumptions, this study derives an equation that estimates the theoretical molding thickness hc of knitted fabric reinforced thermoplastic composites (KFRTC). This is required for controlling the actual molding thickness of KFRTC that are produced by hot pressing knitted preforms made from reinforcing fiber/matrix fiber commingled yarns. The relationship between the optimum actual molding thickness h that can result in composites with higher tensile strength and lower void content and the theoretical molding thickness hc are also determined experimentally in this study. It is found that the composites produced can have higher tensile property and lower void content when h and hc satisfy h = khc (0.85 ≤ k ≤ 0.95). This estimation of h contributes to manufacturing KFRTC.

Four groups of knitted glass fabric reinforced polypropylene (PP) composites with different cooling conditions are prepared by changing the method used in the cooling period. The crystal structure of the matrix in composites arising from different cooling conditions is studied using wide angle X-ray diffraction. It has been found that the various cooling conditions have no effect on the crystal types of the PP matrix. However, the crystal degree and sizes of microcrystal and spherulite vary with cooling conditions. They increase with the decrease of the cooling speed and the prolongation of the cooling time.

Tamoxifen citrate (TAM)-loaded polyacrylonitrile (PAN) fibers were prepared using an improved wet-spinning technique. TAM was used as a model drug to evaluate the potential application of the loaded fiber system for drug delivery. PAN was first homogeneously dissolved in the N,N-dimethylacetamide (DMAc) solution containing TAM and then the co-dissolving solution was solidified to prepare the fibers using a wet-spinning method. Chemical, morphological and mechanical property characterizations were carried out, as well as the studies of the drug release properties. TAM was successfully encapsulated into a monofilament fiber, and this system was stable in terms of high loading capacity and effectiveness in release. The diameter of drug-loaded fiber was in the range of 40-60 microm. The best values of the tensile strength at 2.968 cN/dtex and breaking elongation at 14.9% of drug-loaded fibers were obtained when the drug loading content was 23.1 wt.%. These characteristics were suitable for the weaving process. The in vitro release experiment indicated that constant drug release from the fiber was observed for a long duration of time. Kinetic studies demonstrated that the system followed the Higuchi kinetics. These findings demonstrate that controlled release of drugs from PAN fibers could be potentially useful in drug delivery systems.

Tamoxifen microcapsules and drug loaded medicated fabrics were investigated. The microcapsules were prepared using a complex coacervation procedure involving gelatin B and acacia gum. The morphology, particle size, drug loading capacity and in vitro release characteristics of the drug microcapsules were optimized for coating tamoxifen microcapsules onto the cotton fabrics. Infrared (IR) spectra and SEM were used to characterize the medicated fabrics and air permeability and laundering testing were undertaken to determine the efficiency and effectiveness of the system. Results showed that optimum condition for the microcapsules was at drug/polymer ratio 1:4, polymer concentration 3%, and rate of stirring 1000 rpm. In vitro release assays demonstrated that the tamoxifen was liberated over 10 h after an initial bust rate period. SEM images illustrated that the tamoxifen microcapsules were spherical in shape and were also tightly fixed on to the cotton fabrics fast. These observations demonstrate that we have designed and fabricated a medicated system that potentially could be applied within a transdermal drug delivery system and so act in a system for the treatment of breast cancer.