Preparation method of dry high-hydrophilic polyvinylidene fluoride hollow fibrous membrane

Preparation method of dry high-hydrophilic polyvinylidene fluoride hollow fibrous membrane

  • CN 101,745,324 B
  • Filed: 12/10/2009
  • Issued: 03/11/2015
  • Est. Priority Date: 12/10/2009
  • Status: Active Grant
First Claim
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1. a preparation method for dry high-hydrophilic polyvinylidene fluoride hollow-fibre membrane, is characterized in that comprising the steps:

  • 1) by percentage by weight be 16 ~ 22% polyvinylidene fluoride resin, percentage by weight be 56 ~ 65% solvent, percentage by weight be 15 ~ 22% additive add in casting solution reactor, stir 12 ~ 24 hours at 60 ~ 90 DEG C, filtration, vacuum defoamation obtain casting solution in 12 ~ 36 hours, and the number-average molecular weight of polyvinylidene fluoride resin is 1 ×

    10 5~ 1.0 ×

    10 6;

    2) be 2 ~ 6% amphipathic copolymer hydrophilic modifying agent methyl methacrylate-monomethyl ether polyethylene glycol oxide methylmethacrylate copolymers by percentage by weight, percentage by weight is 12 ~ 20% polyvinylidene fluoride resins, percentage by weight be 56 ~ 75% solvents and percentage by weight is that 10 ~ 18% additives add in coating liquid reactor, stir 12 ~ 16 hours at 60 ~ 80 DEG C, filtration, vacuum defoamation obtain coating liquid in 12 ~ 36 hours, and Kynoar number-average molecular weight is 1 ×

    10 5~ 1.0 ×

    10 6;

    3) to be the casting solution of 65 ~ 90 DEG C and coating liquid and temperature by temperature be, and the core liquid of 15 ~ 40 DEG C carries out coextrusion by three layers of bushing type spinning head, and through 2 ~ 14cm Air flow, the coagulation bath exchange system immersing 20 ~ 40 DEG C obtains former film;

    4) former film first being immersed temperature is that the second hydrophilic bath 2 ~ 3 minutes is immersed in 20 ~ 60 DEG C of first hydrophilic bath again after 1 ~ 2 minute, the agent of amphipathic copolymer hydrophilic modifying is made to form gel layer, again film silk is dried naturally, finally make dry high-hydrophilic polyvinylidene fluoride hollow fiber ultrafiltration membrane;

    Wherein, step

         1) and step

         2) described in solvent be one or both in dimethylacetylamide, dimethyl formamide, 1-METHYLPYRROLIDONE, dimethyl sulfoxide (DMSO), trimethyl phosphate or triethyl phosphate;

    Step

         1) and step

         2) described in additive be two or three in polyethylene glycol, polyvinylpyrrolidone, polyvinyl alcohol or Tween-80 type emulsifying agent;

    Step

         3) described in core liquid consist of;

    percentage by weight is the dimethylacetylamide of 25 ~ 60%, and percentage by weight is the alcohols of 10 ~ 25%, and percentage by weight is the water of 25 ~ 50%.

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