Synthesis And Properties Of Nonionic Waterborne Polyurethane Based On Hydroxylated Plant Oil With Multi-double Bonds

The molecular structure of the nonionic waterborne polyurethane does not haveions, so it is present in acid and alkali environment. Because of its excellent stability,it can be widely used in the field of stabilizers and polymer surfactants.Plant oils not only have the advantages of universal availability, non-toxic,natural degradation and low price, but also have some highly reactive sites includinga double bond, allyl position and ester groups. Accordingly, plant oils have beenwidely used in synthesizing polymer materials. Because the double bonds reaction inthe polymerization process is relatively complicated, tung oil and linseed oil with themaximum content of double bonds are seldom used in the field of nonionicwaterborne polyurethane. It is expected to get functional nonionic waterbornepolyurethane with excellent performance by introducing tung oil and linseed oil intomolecular structure.Firstly, TG/DSC were used to study the thermal decomposition process andkinetics of two hydroxylated linseed in nitrogen and air by TG/DSC, especially thepyrolysis change of double bond in air atmosphere. Then hydroxylated tung oil (HTO)and hydroxylated linseed (HLO), polyethylene glycol (PEG) and dicyclohexylmethane diisocyanate (HMDI) were used to prepare nonionic waterbornepolyurethane based on hydroxylated plant oil with multi-double bonds. The nonionicwaterborne polyurethane structures were characterized by IR and NMR, theinfluences of the plant oil structure, plant oil content, PEG molecular weight, plant oiltypes on the performance of nonionic waterborne polyurethane were studied andanalyzed by the particle size, dynamic mechanical properties, cloud point, the thermaldecomposition,etc. Finally, the application of nonionic waterborne polyurethanebased on HTO as a stabilizer was studied by physically blending of amphotericwaterborne polyurethane. Following are the results:(1) The thermal stability of HLO from alcoholysis is better than HLO fromaminolysis, the oxidation and crosslinking reaction temperature range of thenon-conjugated double bonds in HLO is around190℃~330℃. (2) The particle size of nonionic waterborne polyurethane based on HTO andHLO is between10~50nm, and the stability is good. The ability to reduce surfacetension, cloud point and thermal stability are improved compared with theconventional nonionic waterborne polyurethane without plant oil, of which the cloudis increased to88℃and surface tension is decreased to31mN/m.(3)The content and types of plant oil have large effect on the performance ofnonionic waterborne polyurethane based on hydroxylated plant oil. The particle size,film hardness and storage modulus are all increased with the content, and thus thethermal stability is increased. The cloud point, surface tension, emulsification abilityand thermal stability of nonionic waterborne polyurethane based on HLO are betterthan nonionic waterborne polyurethane based on HTO, the cloud point and thermalstability of nonionic waterborne polyurethane based on hydroxylated plant oil fromalcoholysis is better than that from aminolysis, of which the foam properties andcalcium soap dispersing ability of nonionic waterborne polyurethane based on HTOfrom aminolysis are better than AEO9, which are12.5ml and2.7ml, respectively.(4) The ethoxy content in molecular structure increases with the increase of thePEG molecular weight, which will increase the cloud point and enhance theemulsification performance of nonionic waterborne polyurethane.(5) Compared with conventional nonionic waterborne polyurethane withoutplant oil, nonionic waterborne polyurethanes based on HTO have good stabilizingeffect on the physical blends of amphoteric waterborne.