Water-repellent fabric and preparation method therefor

Abstract

Disclosed are a water-repellent fabric and a preparation method therefor. A short carbon chain fluoroalkyl alcohol with different fluorine atom numbers used as a starter is firstly treated with an acylation reagent to generate a short carbon chain fluoroalkyl bromoacetate, and is then synthesized with N,N-bis(p-toluenesulfonyl) hydrazine to form a short carbon chain fluoroalkyl diazoacetate monomer, a fabric is respectively treated with an acylation reagent and N,N″-dimethylbenzenesulfonyl hydrazide in sequence to prepare a diazotized fabric having grafting sites on the surface thereof, and finally, a fluorine-containing polymer having a single carbon repeating unit is grafted to the surface of the fabric via a covalent bond by means of carbene polymerization, and thus a hydrophobic modified fabric is prepared. The entire reaction is carried out at a low temperature/room temperature, the operation is simple, and the process is environmentally friendly.

1 . A water-repellent fabric, wherein: the water-repellent fabric comprises a fabric and a covalent grafting fluoropolymer by carbene polymerization on the surface of the fabric. 
     
     
         2 . The water-repellent fabric according to the  claim 1 , wherein: the structural formula of the covalent grafting fluoropolymer by carbene polymerization is as follows: 
       
         
           
           
               
               
           
         
         Rf represents fluoroalkyl. 
       
     
     
         3 . The water-repellent fabric according to the  claim 2 , wherein: a fluorine atom number of the fluoroalkyl is 3-15. 
     
     
         4 . The water-repellent fabric according to the  claim 1  is applied in the preparation of waterproof materials. 
     
     
         5 . A preparation method of the water-repellent fabric according to the  claim 1 , wherein: the method comprises the following steps: under the action of a catalyst, place the fluoroalkyl diazoacetate and the active fabric in an organic solvent, and the fluoropolymer is covalently grafted to the fiber surface of the fabric by means of carbene polymerization to obtain the water-repellent fabric; the active fabric is a fabric containing a grafting site. 
     
     
         6 . The preparation method of the water-repellent fabric according to the  claim 5 , wherein: a fluorine atom number in the fluoroalkyl diazoacetate is 3-15; the grafting site is diazo. 
     
     
         7 . The preparation method of the water-repellent fabric according to the  claim 5 , wherein: the catalyst is palladium chloride; the organic solvent is one or more of tetrahydrofuran, dichloromethane and ethanol; the carbene polymerization is carried out under oscillation or stirring. 
     
     
         8 . The preparation method of the water-repellent fabric according to the  claim 5 , wherein: the fluoroalkyl alcohol reacts with bromoacetyl bromide to obtain fluoroalkyl bromoacetate, and then fluoroalkyl bromoacetate reacts with N,N″-dimethylbenzenesulfonyl hydrazide to obtain fluoroalkyl diazoacetate; the fabric is acylated and then reacted with N,N″-dimethylbenzenesulfonyl hydrazide to prepare the active fabric. 
     
     
         9 . The preparation method of the water-repellent fabric according to the  claim 8 , wherein: the reaction of fluoroalkyl alcohol and bromoacetyl bromide is carried out in the presence of alkali; the reaction of fluoroalkyl bromoacetate and N,N″-dimethylbenzenesulfonyl hydrazide is carried out in the presence of organic acid binding agent. 
     
     
         10 . The preparation method of the water-repellent fabric according to the  claim 8 , wherein: the fluorine atom number of the fluoroalkyl is 3-15.