Preparation And Properties Investigation Of Polymer Alloy Membrane Materials

In this paper, we used some kinds of polymer and cellulose to prepare the membrane materials of PVC/EC, PVA/PA-6 and PA-170/CA. The compability and thermal stability of blending alloys were studied using viscometry, refractive index, FTIR, DSC and TG. The interfacial seperation properties and the hydrophilicity of alloys were characterized by means of the HPLC and Contact angle. The main contents of this article consist of following points:1. This paper introduces the situation of membrane separation technology, the classification of membrane, the modification of polymer membrane material, the principle to choose the membran material and the trend of the development of polymer membrane material. It also provides a kind of design idea that blending different types of polymer materials to form a polymer blends with special performance. That will improve the quality of the original polymer and help to obtain good quality polymer membrane material.2. This paper introduces the basic concept of polymer blending and the theory about compatibility of the blend. According to the design idea, the 3 groups polymer blends PVC/EC, PVA/PA-6, PA-170/CA are prepared by means of solution blending. The reduced viscosity of PVC/EC,PVA/PA-6,PA-170/CA solution were measured by relative viscometry. Then we can get the relationship between trait viscosity [η] and component of the blending solution. The relationship between absolute viscosity of PVC/EC and quality component of PVC/EC were measured under the condition of the same temperature with different concentration and the same concentration with different temperature. The results show that the trait viscosity [η] of PVC/EC,PVA/PA-6,PA-170/CA have good linear relationship with component of the blending solution. When the concentration is fixed, the compatibility of PVC/EC gets better with the temperature's increase. When the temperature is fixed, the compatibility of PVC/EC gets worse with the concentration's increase. The absolute viscosity of PVC/EC solution and quality component of PVC/EC have good linear relationship under the condition of 50℃, 4mg/mL. It shows that PVC and EC have blended on the level of molecular. The refraction index of this 3 groups blending solution have good linear relationship with component of the polymer blends. So all of PVC/EC,PVA/PA-6,PA-170/CA have good compatibility.The solid alloy membrane material of PVC/EC,PVA/PA-6,PA-170/CA were prepared by the means of liquid-solid phase transformation. The solid alloy material were mesured by the differential scanning calorimetry, the results show that 3 groups solid alloy material have only one Tg. It proves the 3 groups solid alloy material have good compatibility. FTIR and TG can auxiliary prove the compatibility of PVC/EC,PVA/PA-6,PA-170/CA and the results of TG can also show us blending with EC,PA-6,CA the thermal stability of PVC/EC,PVA/PA-6,PA-170/CA are improved.3. This paper introduces the basic theory of high performance liquid chromatography(HPLC) and the theory of selecting membrane material. The PVC/EC,PVA/PA-6,PA-170/CA alloy was prepared by means of solution blending and liquid-solid phase transformation (L-S). The blends were used as column packing material of high performance liquid chromatography. The interfacial adsorption property,hydrophilicity,polar parameters,nonpolar parameters and interfacial affinity of PVC/EC,PVA/PA-6,PA-170/CA alloy were studied by HPLC. The results shew that: With the increase in EC content, the hydrophilicity of PVC/EC alloy membrane was improved, separation performance of non-dissociable polar organic was better than pure PVC; The hydrophilicity and swelling of PVA was obviously improved by blending with PA-6, PVA/PA-6 alloy is suitable for desalting and desaccharifying; With the increase in CA content, the hydrophilicity of PA-170/CA alloy membrane was improved, the PA-170/CA alloy became easy to filming.The solution blending was used to get some special polymer blending system. Through this method the quality of original polymer can be improved. Using HPLC to study the interfacial separation property of membrane material and selecting membrane material were not reported. It is pioneering work. Using HPLC to simulate the equilibrium conditions of membrane separation technology processes is very novel. This work will be a useful reference for the process of orientational membrane making.