So far, already developed waterproof and breathable membranes with hydrophilic non porous and microporous type have advantages and disadvantages, each of them depend on their structure, morphology and polymers which were composed their. Therefore, in the first study, hydrophilic polyurethane of non ...
So far, already developed waterproof and breathable membranes with hydrophilic non porous and microporous type have advantages and disadvantages, each of them depend on their structure, morphology and polymers which were composed their. Therefore, in the first study, hydrophilic polyurethane of non swelling type was synthesized with reactive silicone oil of a mono-terminal and a bi-terminal type for the hydrophilic non porous membrane with improved performance & property. The non swelling membranes were prepared on a release paper using by synthesized polyurethane resin through dry coating process. The properties and performance of membranes were analyzed compared with existing products. The conclusion is as follow on its test result. Hydrophilic polyurethane (PU) was synthesized by one shot process to get good non swelling effect and to keep high breathability using reactive silicone oil of mono terminal type and bi-terminal type. We also blended non reactive silicone oil with pure hydrophilic PU to compare non swelling effect and breathability with hydrophilic PU synthesized by above mentioned 2 types of reactive silicone oils. The hydrophilic films were analyzed by nuclear magnetic resonance spectroscopy (NMR), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photo electron spectroscopy (XPS), energy dispersive spectrometry (EDS), breathability, water proofness, tensile strength, contact angle and swelling effect. The results showed that the film made by hydrophilic PU which was synthesized with mono terminal type silicone oil provided good non swelling effect and acceptable water vapor permeability due to surface properties its modified. In the second study, to improve limitations of hydrophilic non porous membranes such as high swelling problem and non air permeability, Tried research about electrospun nanofiber mat improved strength and durability for practical applications. For the this purpose, hydrophobic polyurethane for electrospinning was synthesized by one-shot process with PPG/PEA/MEG/MDI and the PU nanofiber was prepared by electrospinning. In this study, electrospun PU multi-membranes were prepared with various coating thickness ratio of base resin to top resin, where the base resin contains melamine curing agent and acid catalyst and the top resin contains water-repellent agent of fluoro-carbon compounds. The PU nanofiber multi-membranes were analyzed by field-emission scanning electron microscopy, differential scanning calorimeter, breathability, tensile strenth, air permeability and water resistance. The results showed that the PU multi-membrane provided excellent waterproof and water vapor permeability. In the final study, synthesized solvent free type water based polyurethane(WBPU) with TMXDI(META-tetramethylxylyne diisocyanate) as aliphatic isocyanate to prepare more environmental friendly membranes, This TMXDI based WBPU does not need any kinds of solvents in the manufacturing process as well as final product. Unfortunately, electrospinnability of only TMXDI based WBPU was not good due to too low viscosity and small molecular weight. Although many types of PVA nanofibers were prepared using electrospinning technique, PVA nanofibers blends with PU, especially WBPU, have not been reported yet. In this study, the PVA nanofiber mates containing different amounts of WBPU were successfully prepared using electrospinning technique. The effects of WBPU on PVA nanofiber formation and the properties were studied. Ultrafine PVA/WBPU submicron fibers were produced by the electrospinning method in aqueous solution. The nanofibers were characterized by FE-SEM, XRD, TGA, and tensile strength testing machine. The polymer concentration and mass ratios were the important factors influencing the electrospinnability and the morphology of the electrospun nanofiber mats. The elongation of PVA/WBPU nanofibers was improved as much as about 60-260% comparing to the pure PVA nanofibers. The results suggested that the optimum fabrication conditions for PVA/WBPU nanofiber are 15wt.% of total solid concentration with a mass ratio from 7/3 to 5/5. At these conditions, higher strength of and enhanced elasticity of electrospun nanofiber was obtained. Furthermore, higher thermal properties could be obtained with a higher mass ratio of PVA in the PVA/WBPU blend nanofiber mats. The electrospun PVA/WBPU membranes could have potential applications in wound dressings because of their higher water uptake. Besides, blended PVA/WBPU nanofiber mat was obtained excellent WVR(water vapor resistance) and WVP(water vapor resistance), AP(air permeability) at the optimum condition above mentioned. Therefore the electrospun PVA/WBPU membranes could have another potential applications in high breathable garment for spring and summer season, high performance filter, medical patch because of their excellent breathability and air permeability.
So far, already developed waterproof and breathable membranes with hydrophilic non porous and microporous type have advantages and disadvantages, each of them depend on their structure, morphology and polymers which were composed their. Therefore, in the first study, hydrophilic polyurethane of non swelling type was synthesized with reactive silicone oil of a mono-terminal and a bi-terminal type for the hydrophilic non porous membrane with improved performance & property. The non swelling membranes were prepared on a release paper using by synthesized polyurethane resin through dry coating process. The properties and performance of membranes were analyzed compared with existing products. The conclusion is as follow on its test result. Hydrophilic polyurethane (PU) was synthesized by one shot process to get good non swelling effect and to keep high breathability using reactive silicone oil of mono terminal type and bi-terminal type. We also blended non reactive silicone oil with pure hydrophilic PU to compare non swelling effect and breathability with hydrophilic PU synthesized by above mentioned 2 types of reactive silicone oils. The hydrophilic films were analyzed by nuclear magnetic resonance spectroscopy (NMR), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photo electron spectroscopy (XPS), energy dispersive spectrometry (EDS), breathability, water proofness, tensile strength, contact angle and swelling effect. The results showed that the film made by hydrophilic PU which was synthesized with mono terminal type silicone oil provided good non swelling effect and acceptable water vapor permeability due to surface properties its modified. In the second study, to improve limitations of hydrophilic non porous membranes such as high swelling problem and non air permeability, Tried research about electrospun nanofiber mat improved strength and durability for practical applications. For the this purpose, hydrophobic polyurethane for electrospinning was synthesized by one-shot process with PPG/PEA/MEG/MDI and the PU nanofiber was prepared by electrospinning. In this study, electrospun PU multi-membranes were prepared with various coating thickness ratio of base resin to top resin, where the base resin contains melamine curing agent and acid catalyst and the top resin contains water-repellent agent of fluoro-carbon compounds. The PU nanofiber multi-membranes were analyzed by field-emission scanning electron microscopy, differential scanning calorimeter, breathability, tensile strenth, air permeability and water resistance. The results showed that the PU multi-membrane provided excellent waterproof and water vapor permeability. In the final study, synthesized solvent free type water based polyurethane(WBPU) with TMXDI(META-tetramethylxylyne diisocyanate) as aliphatic isocyanate to prepare more environmental friendly membranes, This TMXDI based WBPU does not need any kinds of solvents in the manufacturing process as well as final product. Unfortunately, electrospinnability of only TMXDI based WBPU was not good due to too low viscosity and small molecular weight. Although many types of PVA nanofibers were prepared using electrospinning technique, PVA nanofibers blends with PU, especially WBPU, have not been reported yet. In this study, the PVA nanofiber mates containing different amounts of WBPU were successfully prepared using electrospinning technique. The effects of WBPU on PVA nanofiber formation and the properties were studied. Ultrafine PVA/WBPU submicron fibers were produced by the electrospinning method in aqueous solution. The nanofibers were characterized by FE-SEM, XRD, TGA, and tensile strength testing machine. The polymer concentration and mass ratios were the important factors influencing the electrospinnability and the morphology of the electrospun nanofiber mats. The elongation of PVA/WBPU nanofibers was improved as much as about 60-260% comparing to the pure PVA nanofibers. The results suggested that the optimum fabrication conditions for PVA/WBPU nanofiber are 15wt.% of total solid concentration with a mass ratio from 7/3 to 5/5. At these conditions, higher strength of and enhanced elasticity of electrospun nanofiber was obtained. Furthermore, higher thermal properties could be obtained with a higher mass ratio of PVA in the PVA/WBPU blend nanofiber mats. The electrospun PVA/WBPU membranes could have potential applications in wound dressings because of their higher water uptake. Besides, blended PVA/WBPU nanofiber mat was obtained excellent WVR(water vapor resistance) and WVP(water vapor resistance), AP(air permeability) at the optimum condition above mentioned. Therefore the electrospun PVA/WBPU membranes could have another potential applications in high breathable garment for spring and summer season, high performance filter, medical patch because of their excellent breathability and air permeability.
주제어
#breathable membrane polyurethane reactive silicone oil electrospinning
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