Preparation Of 3D Polyurethane/polyvinylbutyral Nanofiber Sponge

Herein,we take advantage of polyurethanes,segmented polymers with highly elastomeric behaviours.They are also widely used polymers in filtration,heat insulation systems,mechanical performance systems and biomedical applications.This is due to the inherent,relative nonthrombogenicity of their surfaces and easy synthesis to different forms.Polyvinyl butyral(PVB)contains hydrophilic and hydrophobic vinyl alcohol and butyral groups which function as agents of polymer cementing glue and binders for organic medieties.PVB is resin strong in binding,sharp in optical clarity,flexible and tough.This presents them to be used as a constituent part of a composite while solving an issue of applications in numerous fields like composites and nanocomposites.A three-dimensional(3D)network structure that has many striking properties such as low density,high porosity,reversible compressibility and flexibility was fabricated to mimic a natural sponge.In this paper,PU and PVB were electrospun and build into such a 3D structure capable of fulfilling several functionalities based on the specific building blocks.We successfully overcame the challenge that came during transformation of electrospun fibrous membrane to building 3D structures with the nanofibres avoiding just stacking of fibre mats.We formulated a method specifically for harnessing the fibrous composition of PU/PVB membranes into a well collated crosslinked sponge edifice.The superlight weight and mechanical strength of the fibrous sponge create an expansion in the possibilities of applications for PU materials.For PU/PVB 3D sponge,PVB mainly worked as binding and reinforcement agent.A unique method to promote the binding of PU nanofibers within the sponge was designed using ethanol which allowed PVB to dissolve and conglutinate PU fibres together.This phenomenon resulted in super strong fibrous polymeric sponges after freeze drying.XRD test proved the strong presents of PU and also highly amorphous PVB strain with a higher alcohol content.The sponge models exhibited different levels of resistance to stress according to quality ratios with the model made from 7:3 PU to PVB ratio showing the highest yield point to stress.A measurement of over 2Mpa was recorded for this model as it showed different deformation along its length.The 3D fibrous sponges showed great compression recovery strength.It showed complete recovery after being subjected to manual hand strain.From these results,it was possible to harness the properties of PVB as a binding agent to promote the polymeric properties.This gives a wide scope of possibilities in building polymeric nano blocks using different polymers in-situ.This work shapes the possibility of controlling weight per unit volume in order to promote shaping fibrous sponges to different specifications.Stiffer to fluffy low-density 3D sponge PVB/PU material could also be synthesised depending on intended end use properties.More so,we demonstrated the absorption capacity of the sponge using oil.The sponge showed great mechanical strength and absorption capacities up to 81 times the dry weight of the sponge.