Study On Polyurea Protective Coating For Weather Resistance And Corrosion Resistance

With the rapid development of economy and national important projectsconstruction. Polyurea is more widely used in all kinds of important field as aprotective material. So, study the aging properties of polyurea under differentconditions is necessary.This paper mainly studies the polyurea coatings in differentcuring temperature, outdoor natural insolated, ultraviolet ray artificial acceleratedaging, acid or alkali or salt corrosive medium properties.First, study Qtech A1and Qtech A2are two different polyurea formulationsperformance changes under60℃or23℃conditions. And Qtech B1and Qtech B2performance changes at23℃or15℃conditions. The study results shown that themechanical properties in60℃condition cured2d is equivalent to7d cured in23℃.Qtech A1cured in60℃for7d,the growth rate of tensile strength and elongation atbreak is68.58%and20.55%respectively. Qtech A1cured in23℃for7d,the growthrate of tensile strength and elongation at break is74.07%and3.64%respectively.Polyurea mechanical properties growth rate is lower cured in15℃than cured in23℃. Qtech B1polyurea is suitable for low temperature used. The tensile strength ofpolyurea cured in15℃and23℃is24.49MPa and26.19MPa respectively. Theelongation at break is of polyurea cured in15℃and23℃is553.07%and537.09%,respectively.Natural ageing research used Qtech F1, Qtech F2and Qtech F3three kinds ofpolyurea coatings for study. Mainly studies the mechanical properties and ATR FTIRand microscopic analysis. The mechanical properties research including glossiness,tensile strength, elongation at breaks. The results show that after270d natural ageingthe glossiness decreased rates were95.86%,79.31%and85.98%respectively. Thetensile strength is decrease0.54%, increase by0.81%and decrease0.36%,respectively. The elongation at break is increased by5.24%,4.08%and2.40%. TheATR FTIR spectra and microstructure showed that three different kinds of polyureachemical bond of N R, C H, C=O bond and C O C in surface occurred breaking andoxidation, but its internal structure is without any changes. Comprehensive resultsshow that after270d natural ageing, the surface of polyurea coatings has taken aparticularly photodegradation ageing, but its internal structure is not affected byaging. Ultraviolet artificial accelerated ageing studies Qtech F4, Qtech F5andQtech F6three different formulations of polyurea coating glossiness, tensile strength,elongation at break changes and ATR FTIR and DSC properties during4000hartificial accelerated ageing. The research results show that after4000h acceleratedageing Qtech F4、Qtech F5å’ŒQtech F6surface glossiness decrease rate is98.80%,97.70%and96.52%respectively. The te nsile strength decrease rate is3.66%、6.13%and7.26%. The elongation at break is decreased4.01%, increased by14.60%anddecreased1.28%, respectively. ATR FTIR spectroscopy and DSC test results indicatesthat polyurea coating surface has an obvious chemical bond fracture or oxidationreaction, but its internal structure has not any changes.The corrosion resistant study Qtech H polyurea coating resisting10%H₂SO₄,10%NaOH and10%NaCl properties in23℃and50℃temperature. Theresults show that Qtech H polyurea coating immersed in10%H2SO4at23℃and50℃for60d, the tensile strength decrease rate is26.54%and33.65%, the elongation atbreak increased by1.21%and decreased1.92%, respectively. Polyurea coatingimmersed in10%NaOH at23℃and50℃for60d, the tensile strength decrease rateis15.88%and20.06%, the elongation at break increased by2.97%and8.99%,respectively.Polyurea coating immersed in10%NaCl at23℃and50℃for60d, thetensile strength decrease rate is17.05%and21.37%, the elongation at break increasedby0.88%and9.07%, respectively. ATR FTIR spectra show that polyurea coatingafter immersed in corrodents for60d, the chemical bond have no any breakingphenomenon.All of the polyurea coatings research results provide important theoretical basis.And the research results will as reference for the future application in projects.