Study On Preparation And Performance Of Water-sensitive Medical Degradable Polyurethane Foam

In nasal surgery,the traditional hemostatic fillers used in the past have the shortcomings of airtightness,hardness,poor liquid absorption,painful plugging,and non-degradability.A porous,flexible,resilient,highly absorbent,and watersensitive filler has been developed.Shape memory,degradable polyurethane foam is very important.In this dissertation,polyethylene glycol(PEG),Liquefied diphenyl methane diisocyanate(L-MDI),water,etc.were used as the main raw materials to prepare high water-absorbent,water-sensitive shape memory and degradable polyurethane foams,which met the requirements of medical,by one-step chemical foaming method.Through density test,microscope observation,infrared spectroscopy,differential scanning calorimetry,thermal weight loss,shape memory performance,mechanical performance,water-absorbing quality,degradation performance and other characterization methods,the amount of foaming agent,PEG molecular weight,R value,and BDO addition were studied.The influence of the amount on the structure and performance of the watersensitive polyurethane foam,and the water-sensitive and degradable polyurethane foam was prepared by blending and grafting oxidized hydroxypropyl starch(OHS),polylactide(PLA)and polylactide-cocaprolactone(PCLA).Concluded as follow:(1)A series of water-sensitive polyurethane foams were prepared by exploring the amount of foaming agent,PEG molecular weight,R value,and BDO addition amount.It is finally determined to use PEG2000,L-MDI and water as the main raw materials.The mass fraction of water used as foaming agent is 1.0 phr,R=1.0,the water-sensitive polyurethane foam has the best water sensitivity and performance.Optimal.At this time,the density of WSPUF is 125.9 kg/cm3,Tm=29.27℃,and tensile strength is 0.548 MPa.After water absorption,it drops below 0.05 MPa.The water-sensitive shape recovery rate is 100%,and the water absorption rate is 17.22 g/g.(2)After the addition of PLA and PCLA,as the amount of addition increases,ratio of weight loss grow bigger,the water uptake gradually decreases,and the swelling degree gradually decreases.The gel content and tensile strength gradually decrease with the extension of the degradation time.Sensitivity gradually decreases with the increase in the amount of addition,but it shows obvious degradability.When PCLA was added at 15 phr,it degraded after 30 days.