Synthesis And Application Of Vegetable Oil-Based Fluorocarbon Water Repellent Agents On Cotton Fabrics

Water repellent finishing has attracted more attention nowadays.There are also various kinds of water repellent agents in the maket recently while the florine-containing water repellent agent has occupied the mostly part among the maket recently. Fluorocarbon compounds confer extreme hydrophobicity and water insolubility to polymers, which can lower the surface tension of fabrics largely while it has been favored by textile market for its unique oil repellency, anti-soiling ability, durability to washing and air permeability. However, the long chain organic fluorine agents with long perfluoroalkyl groups have been found to resist degradation, bioaccumulate in human and animal tissue and in limited use.These organic fluorine agents were synthetized from the cracked product of petroleum, which has been increasingly exhausted. Natural vegetable oil is seen as the most important category among many of natural renewable materials, which are the most promising oil alternative raw materials when synthetizing polymeric materials due to raw materials readily available, cheap, biodegradable, and many have become the research focus in recent years.Short-chain fluorocarbon agent has been extensively studied because of its easy to resist degradation vegetable oils constitute a suitable alternative, as they are wholly biodegradable, nontoxic. In this paper, different unsaturated vegetable oils(soybean oil and linseed oil)were choosen to prepared vegetable oil-based fluorocarbon water repellent agents. Main researches are as follows:(1)The main physical chemistry characteristics of four vegetable oils were analyzed through measuring saponification value and iodine value to find out characteristics of potential plant that are suitable for further treatment and modification. (2) Different fluorine containing water repellent agents were synthesized by chemical modifications of different vegetable oils through several reactions, including saponification, acidification, acylation of vegetable oil and trans-esterification with 2,2,2-trifluoroethanol and 2,2,3,3-tetrafluoropropanol, then polymerized with styrene. The structures of the modified vegetable oils were characterized by FT-IR and NMR.(3)By evaluating contact angle, time of disappearance of water, whiteness, breaking strength of the finished products and the fibre structure, the optimum cotton fabric finishing conditions were explored. The cotton fabrics finished with the modified vegetable oils showed excellent water repellency, while other properties of the cotton fabrics, such as whiteness and breaking strength declined to certain level while the fabrics'performance was affected a little. The tetrafluoropropapanol modified linseed oil displayed the highest water repellency among all modified oils (contact angel was 141°, disappearance time of water drop was 6480s). Moreover, the performance of these reagents after repeat launderings was also researched. All the treated fabrics exhibited good durability of water repellency. The tetrafluoropropapanol modified linseed oil showed the best durability among all the vegetable oils. Even after 20 cycles of washing, the contact angle of treated samples remained about 130°or higher.