js77999金沙com
PVP K30在中空纤维超滤膜中运用
js77999金沙com
 
对膜外面表面的影响
用PVPK30做添加剂得到的膜外面匀称、光亮、整洁,其缘由是PVP的粘度大,成膜机能较好。
  js77999金沙com
对铸膜液粘度的影响 85850.com
PVP水溶性最好,构成的嵌段构造更易以密集的体式格局聚积,铸膜液粘度增添幅度最大。
 
对膜孔隙率的影响
PVPK30做添加剂构成的膜的孔隙率较下。PVP具有优越的亲水性,在成膜后易于被洗去,具有较好致孔感化,同时膜的皮层因为PVPK30含量增添,改动了大分子在皮层的分列状况,易于构成大孔,使得皮层的孔隙率上升,那是PVPK30做添加剂构成的膜孔隙率较PEG1000和T80 下的缘由。 9159.com
  金沙0027jscom
对膜火通量的影响
PVP K30水溶性最好,增加PVP K30的膜浸入凝胶浴以后敏捷发作相变,其缘由是因为PVP K30 会在膜和氛围的界面富集,其构成的膜火通量便对照下。当PVP K30的质量分数为6%时,五孔的表面皮层构造对照松散,层内构造微孔数目较多并且散布较为匀称,中央局部是大的类指状孔穴和海绵状孔构造,这类膜结构具有较下的火通量,其机械性能也较好。跟着PVP K30 的质量分数的进一步增大,到达8%时,固然中空纤维膜的支持层也是大的孔穴,然则孔巨细不均匀,那对膜的机械性能晦气。表面皮层也对照致密,同时海绵状构造中的微孔孔径也变小,因而膜的火通量变低。
 
对膜的断裂强度和拉伸率的影响
PVP K30不只能增大膜的伸长率,并且能使膜的抗拉强度有较大水平的增大。跟着铸膜液粘度的增添,膜的拉伸强度也大大增添,且PVP K30的质量分数为6%时造得的膜的机械性能较好。含量低时,因为大分子之间打仗几率小,大分子之间建立起的物理交联点也就少,没法构成凝胶体,因而纤维的断裂强度和断裂伸长率均很低,纤维较脆,而含量较大时则致使缠结点密度增大,纤维的断裂强度和伸长率获得有用进步。因为PVP的亲水性好,它做添加剂造得的铸膜液的粘度较大,以是膜的机械性能对照好。
 
结论
PVP K30使溶液的粘度增大最多。粘度的改动间接影响到五孔共混膜结构和机能的改动。用PVP K30做添加剂制备的共混膜,最洪水通量要优于T80 和PEG1000,其机械性能也具有较大的上风。对固体质量分数为17%的铸膜液,当PVP K30到场质量分数为6%时造得的中空纤维膜可达较佳机能。
用PVP K30 做添加剂得到的膜外面匀称、光亮、整洁。
,

Chemical Structure:  Homopolymer of vinyl pyrrolidone CTFA Nomenclature:  POLYVINYLPYRROLIDONE ( Povidone , PVP )
CAS NO: 9003-39-8
Physical Properties: 

PVP exists as powder or aqueous solution. It can dissolve in water and a variety of organic solvents. It has good hygroscopicity, film-forming capability, complexing ability and physiological compatibility.

TEST   ITEMS
SPECIFICATIONS
Appearance
White powder
K V alue                             
2 9 -32
M ono m er                             ppm
≤ 10  
Impurity B(2-pyrrolidone)               %
≤ 3.0
Moisture                             %
≤ 5.0
Sulfate a sh                           %
≤ 0.1
PH value  
3-7
Formic acid                        %
≤ 0.5
Nitrogen                             %
11.5-12.8
Aldehyde  (as acetaldehyde)             %
<0.05
Heavy metal  (as lead)                     ppm
<10
Hydrazine                             ppm
≤ 1 .0
Peroxide                            ppm
<400

Application
Cosmetics:
PVP-K series can be used as film-forming agent, viscosity-enhancing agent, lubricator and adhesive in hair sprays, mousse, hair-fixing gels and solution. They are also useful auxiliary materials in skin-care product, hair-dying reagent, shampoo, lipstick, deodorant, sunscreen and dentifrice.
Pharmaceutical:
PVP-K30 (Pharmaceutical grade) is a kind of new excellent pharmaceutical excipient. It is mainly used as binder for tablet and granule, dissolving assistant for injection, flow assistant for capsule, dispersant for liquid medicine and pigment,stabilizer for enzyme and heat-sensitive drug, coprecipitant for poorly soluble drugs, lubricator and antitoxic assistant for eye drug.PVP has been used as excipient in more than one hundred drugs.
Other Utility:
Suspensant, dispersant and emulsifier Disinfector Paint and coating Printing ink Textile and dyestuff Building material Paper making TV kinescope Polymer ultra-filtration membrane, micro-filtration membrane Glass fiber