| At present,synthetic leather has a good comprehensive performance and is widely used in furniture,shoes,clothing,luggage and other industries.However,compared with high-grade natural cattle leather and sheep leather,it still has unstable structure and easy to peel off the base fabric and inner layer;the outer layer has poor wear resistance,wrinkle resistance and weather resistance;the temperature change has a better influence on the synthetic leather.Great question.In this paper,a composite foam material was prepared by using PP non-woven felt instead of PP/PET base fabric and polyurethane foaming pulp as a synthetic leather substrate;and water-based polyurethane for synthetic leather with excellent weather resistance,abrasion resistance and hand feeling was prepared./epoxy resin/acrylate IPN film,as a synthetic leather surface layer;a new synthetic leather structure.The structure completely solves the problem that the internal structure of the synthetic leather is unstable and easy to be peeled off;the abrasion resistance,the wrinkle resistance and the hand feeling of the surface layer are poor.The performance of the target product was characterized by FTIR,particle size analyzer,TGA,DSC,DMA,SEM and other testing methods.(1)In this experiment,core-shell crosslinked waterborne polyurethane/epoxy/acrylate emulsion was synthesized from IPDI,PTMG,DMPA,HEA and E-51.Using FTIR test,it was proved that epoxy resin,HEA and acrylate were connected to the molecular chain of polyurethane.Polyurethane,epoxy resin and acrylate formed a stable core-shell crosslinked structure.With the increase of epoxy resin content,the maximum tensile strength of the film is 7.32 MPa;the maximum tear strength of the film is 29.4 kN/m;the maximum hardness is 58,the tensile strength and tear of the film.The mechanical properties such as strength and hardness are significantly improved.The elongation at break and the permanent deformation during the break are gradually reduced,and the minimum values are 545%and 6.8%,respectively.The water absorption rate was reduced from 7.2%to 5.1%,and the water resistance was improved.As the particle size of the emulsion becomes larger,the stability of the emulsion becomes worse.It can be seen from the SEM that as the epoxy resin content increases,the compatibility of the two phases becomes better and better.The interface of most regions is relatively ambiguous,but there is still phase separation in a small part of the area,and the compatibility of the micro-area still needs to be improved.In addition,the damping peak moves toward the high temperature direction,and the damping temperature range becomes wider,and the temperature range of-60?to40?when tan?is less than 0.2,indicating that the film can maintain good performance in a wide temperature range;The initial decomposition temperature is increased from 195?to 225?,and the thermal stability is improved.(2)In this experiment,IPDI,PTMG,DMPA,TMP,DAAM and ADH were used as raw materials to prepare a film of ketone-ruthenium crosslinked waterborne polyurethane/epoxy resin/polyacrylate IPN structure.Using FTIR testing,it was demonstrated that TMP participates in the reaction,hydrazone bond C=N formation,and formation of acrylate molecular chains.With the increase of TMP content,the maximum tensile strength of the film is 9.17 MPa;the maximum tear strength of the film is 30.8 MPa;the maximum hardness is 68,and the mechanical properties such as tensile strength,tear strength and hardness of the film Both are significantly improved;the elongation at break and the permanent deformation at break are gradually reduced,and the minimum values are 393%and 5.2%,respectively.It can be seen from SEM that the phase interface of the micro-region is fuzzy and the compatibility is good,indicating the interpenetrating network.The structure has been formed,and the structural compatibility is better than that of the core-shell cross-linking method.At the same time,through DMA,as the TMP content increases,the damping temperature becomes higher and higher,the damping temperature range becomes wider and wider,and the temperature range of-40?to 40?when tan?is less than 0.2,indicating that the glue is in a wide temperature range.The film maintains good performance.The initial decomposition temperature of the film increased from 210?to 255?,and the thermal stability was remarkably improved.(4)In this chapter,a pre-polymer method is used to prepare a composite foam by a method in which a PP nonwoven felt is immersed in a polyurethane foaming slurry to co-foam.The tensile strength,tear strength and material rebound rate of the material first increase and then decrease.When the water content is 1.5%,the maximum values are 24.7 MPa,4.2 kN/m,33%,respectively.At this time,the performance of the three is optimal;the density,elongation at break and hardness are gradually reduced,elongation at break,density,hardness were Reduced to 405%,0.20g/cm~3,and 52,respectively.Through stereomicroscope and SEM observation,as the water content increases,the cell size increases,the cell size uniformity decreases gradually,and the total contact area of the cell and PP non-woven mat surface increases first and then decreases,and the bonding ability first increases.After weakening,the peel strength is first increased and then decreased.When the water content is 1%,the maximum peel strength of the material is 23.5 N/cm,and the structure of the composite foam is the most stable.The glass transition temperature of the composite foam was reduced from-40?to-20?;the initial decomposition temperature of the material was lowered from 285?to 255?,and both were completely decomposed at around 500?.The damping peak moves toward the high temperature;the thermal stability of the composite foam is reduced. |
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