产品中心
PVP K30在中空纤维超滤膜中应用
 
对膜表面外观的影响
用PVPK30作添加剂获得的膜表面均匀、光洁、整齐,其原因是PVP的粘度大,成膜性能较好。
 
对铸膜液粘度的影响
PVP水溶性最好,形成的嵌段结构更易以密集的方式堆积,铸膜液粘度增加幅度最大。
 
对膜孔隙率的影响
PVPK30作添加剂形成的膜的孔隙率较高。PVP具有良好的亲水性,在成膜后易于被洗去,具有较好致孔作用,同时膜的皮层由于PVPK30含量增加,改变了大分子在皮层的排列状态,易于形成大孔,使得皮层的孔隙率上升,这是PVPK30作添加剂形成的膜孔隙率较PEG1000和T80 高的原因。
 
对膜水通量的影响
PVP K30水溶性最好,添加PVP K30的膜浸入凝胶浴之后迅速发生相变,其原因是由于PVP K30 会在膜和空气的界面富集,其形成的膜水通量就比较高。当PVP K30的质量分数为6%时,五孔的外表皮层结构比较疏松,层内结构微孔数量较多而且分布较为均匀,中间部分是大的类指状孔穴和海绵状孔结构,这种膜结构具有较高的水通量,其机械性能也较好。随着PVP K30 的质量分数的进一步增大,达到8%时,虽然中空纤维膜的支撑层也是大的孔穴,但是孔大小不均匀,这对膜的机械性能不利。外表皮层也比较致密,同时海绵状结构中的微孔孔径也变小,因此膜的水通量变低。
 
对膜的断裂强度和拉伸率的影响
PVP K30不仅能增大膜的伸长率,而且能使膜的抗拉强度有较大程度的增大。随着铸膜液粘度的增加,膜的拉伸强度也大大增加,且PVP K30的质量分数为6%时制得的膜的机械性能较好。含量低时,由于大分子之间接触几率小,大分子之间建立起的物理交联点也就少,无法形成凝胶体,因此纤维的断裂强度和断裂伸长率均很低,纤维较脆,而含量较大时则导致缠结点密度增大,纤维的断裂强度和伸长率得到有效提高。由于PVP的亲水性好,它作添加剂制得的铸膜液的粘度较大,所以膜的机械性能比较好。
 
结论
PVP K30使溶液的粘度增大最多。粘度的改变直接影响到五孔共混膜结构和性能的改变。用PVP K30作添加剂制备的共混膜,最大水通量要优于T80 和PEG1000,其机械性能也具有较大的优势。对固体质量分数为17%的铸膜液,当PVP K30加入质量分数为6%时制得的中空纤维膜可达较佳性能。
用PVP K30 作添加剂获得的膜表面均匀、光洁、整齐。
,

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