The Preparation And Properties Of PTFE-Chitosan Composite Membranes

In this thesis, using Sodium-Naphthalide Solution, the surface ofpolytetrafluoroethylene (PTFE) micro-pore membrane was modified. The preparationtechnics of Sodium- Naphthalide Solution and the modification effect of the PTFEmicro-pore membrane after treating solution were studied. The study shows that mol ratioof sodium and Naphthalide should be 1:1, and dosage of sodium should excessive 3-5g;solvent should be selected tetrahydrofuran (THF); 20g olefin should be acceded to thesolution in the reacting process to improve its stability; the reacting process needed 2.5hours. The Sodium-Naphthalide solution has very strong action on the modification ofmembrane surface. After treatment the surface element percent composition wassignificantly changed, the C element increased and while the F element decreased.Contact angle with water of the membrane surface minished. Both the wettability andadhesive performance were also improved.In order to empolder multi-functionality of PTFE micro-pore membrane, endow itwith antibacterial capability, a layer of chitosan membrane was adhered to the modifiedPTFE film to make composite membrane. The preparation condition and performance ofthe chitosan membrane were firstly studied in the paper, in order to seek the bestcondition for the preparation of the PTFE-Chitosan Composite Membranes. The studydiscovered that concentration of chitosan solution should be 10g/L; 1mL of 4％glycerinand 0.3mL of 0.5％glutaraldehyde should be acceded to the chitosan solution; dryingtemperature should be 60℃. In this condition, the general performance of the chitosanmembrane was better.By flow casting method, different concentration of chitosan solution was adhered tothe modified PTFE film to prepare composite membranes. The peeling property of thecomposite membranes was tested, and the mechanical properties and the moisture permeable properties of the composite membranes were studied. The study shows thatconcentration of chitosan solution should be 10g/L, drying temperature should be 60℃, inwhich condition the peeling strength and properties of the composite membranes are thebest. The peeling strength will not be influenced by washing. The intensity of thecomposite membranes can be improved clearly only when the thickness of chitosanmembrane exceeds 0.4mm. Moisture permeable quantity of the composite membranes willaugment along with the increase of the concentration of chitosan Solution and theenhancing of the drying temperature.