Research On New Polyurethane Packaging Materials

A new type of polyurethane material was prepared by using hexamethylene diisocyanate(HDI)and 1,6-hexanediol(HDO)as hard segments and polycarbonate diol as soft segment.Adding hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine(TNO),commonly known as Sandan oil antibacterial agent,to prepare an antibacterial polyurethane film for use as an antibacterial packaging film.Polyurethane films(PU films)with different R values were prepared by changing the molar ratio(R value)of isocyanate to hydroxyl groups in the prepolymerization reaction,and the effect of R value on the properties of PU films was investigated.Infrared analysis showed that a new type of PU film was synthesized by HDI,PCDL and HDO.With the increase of R value,the mechanical strength,water contact angle and microphase separation degree of PU film increased gradually,transparency and oxygen permeability.The coefficient is gradually reduced,and the barrier properties and thermal stability are gradually getting better.By changing the content of HDO,PU films with different HDO contents were prepared,and the effect of HDO content on the properties of PU films was investigated.The results show that with the increase of HDO content,the tensile strength of PU film increases first and then decreases,and the elongation at break decreases.With the increase of HDO content,the water contact angle and microphase separation degree of PU film increase.The oxygen permeability coefficient is lowered,and the barrier property and thermal stability are improved.1,4-butanediol(BDO),diethylene glycol(DEG),1,6-hexanediol(HDO),dimethylolpropionic acid(DMPA)and dimethylolbutanoic acid(DMBA)is a chain extender to prepare PU films with different chain extender types,and to study the effect of chain extender types on the properties of PU films.The results show that the mechanical properties,barrier properties and thermal stability of HDO type PU film are the best,the degree of microphase separation and water contact angle are the largest;the mechanical properties,barrier properties,thermal stability and microphase of BDO type and DEG type PU film The degree of separation and water contact angle are both centered;the mechanical properties,barrier properties and thermal stability of DMPA and DMBA PU films are the worst,and the degree of microphase separation and water contact angle are the smallest.PU films with different film formation temperatures were prepared by changing the film formation temperature,and the effect of film formation temperature on the properties of PU films was investigated.The results show that with the increase of film forming temperature,the mechanical properties of PU film become better and then deteriorate,the water contact angle decreases first and then increases,the oxygen permeability coefficient first decreases and then rises,and the barrier property first changes and then changes.Poor;the degree of microphase separation of the PU film gradually:increases with the increase of the film forming temperature,the crystallinity is further enhanced,and the transparency is also gradually decreased.PU films with different TNO contents were prepared by using hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine(TNO)as antibacterial agent,and the effect of TNO content on the properties of PU film was studied.The antibacterial PU film was synthesized by infrared analysis.With the increase of TNO content,the tensile strength of PU film increased first and then decreased,the elongation at break decreased,the contact angle of water increased gradually,the degree of microphase separation,transparency and The oxygen permeability coefficient is gradually reduced,and the thermal stability and barrier properties are gradually improved.The antibacterial film prepared was tested for its antibacterial effect against Escherichia coli,Staphylococcus aureus,Rhizopus and Gray mold by the inhibition zone method.The results showed that with the increase of TNO content,the antibacterial performance of PU film on different strains was improved,but the degree of inhibition was different.