Preparation Of Medical Catheter With Ultrasonic Imaging Ability Using Polyurethane Foam And Porous Starch

Medical catheters are often used for drug delivery,intravenous infusion,hemodialysis,and tumor chemotherapy.It is difficult for doctors to accurately locate them when doing these operations.At present,the medical catheter used does not have the capability of ultrasound imaging itself,and it is necessary to inject a contrast agent and to modify the surface of the catheter to achieve the purpose of ultrasound imaging.This paper proposes to add porous materials such as polyurethane foam(PUF)and composite cross-linked hydrophobic porous starch(CLPSt)to the pellets for preparing medical catheters,so that the prepared medical catheter itself has the effect of ultrasound imaging.The specific research content is as follows:In this study,polyurethane foam was prepared by one-step process.The main raw materials were TEA,water,chain extender(BDO),crosslinking agent(TMP)and foam stabilizer.Their consumption amounts were 5.0%,1.0%,2.0%,1.0%and 2.0%respectively.In addition,polyether polyols(303)/polyether polyols(390)were added.Their compound ratio was 10/2-10/4,and the foam pore size was small and distributed.It can meet the processing conditions.The polyurethane foam materials with excellent properties is cut into pellets and sampled,blended with TPU pellets,and extruded to obtain the wire of the catheter material.The wire is pelletized and injection molded to explore the ultrasonic imaging capabilities and mechanical properties under different ratios.The research results show that when no PUF is added,the wire has no imaging effect,while the ultrasonic imaging effect of TPU/PUF=80/20 and TPU/PUF=70/30 is very obvious.You can clearly see the position of the wire insertion and its mechanical The performance meets the requirements of medical catheter materials.Next,the study used three methods of complex enzyme(glucoamylase and ?-amylase)enzymatic hydrolysis,octenyl succinic anhydride esterification method and Al2(S04)3 cross-linking method to modify the starch for porous and hydrophobic modification.Through SEM,FT-IR,TGA,water contact angle and other methods to characterize its performance,and successfully prepared composite cross-linked hydrophobic porous starch.The CLPSt and TPU pellets were blended and extruded according to the mass ratio,and cooled to obtain the wire of the catheter material.The wire was cut into pellets for injection molding,and the ultrasonic imaging ability and mechanical properties under different ratios were explored.The research results show that the pure TPU wire has no ultrasonic imaging effect under the ultrasonic instrument;when the addition amount of CLPSt is 5%,10%,15%and 20%,the ultrasonic imaging effect of the wire in the pork is very obvious.You can clearly see where the wire is inserted,and its mechanical properties meet the requirements of medical catheter materials.In summary,in this paper,PUF and CLPSt porous materials are added to thermoplastic polyurethane to prepare medical catheters,which can make the prepared medical catheters have the ability of ultrasonic imaging,without the need to modify the ultrasonic coatings of the catheters,which improves the implantation operation.The accuracy of this method is of great significance to achieve the purpose of timely diagnosis and treatment.