The Multi-copolymerization Of Allyl Reactive Emulsifier And The Study Of Acrylic Emulsion Pressure Sensitive Adhesive Structure And Properties

In this paper, acrylic multi-copolymerization emulsion pressure sensitive adhesive (PSA) was prepared by using reactive emulsifier and their influence factors were studied. Characterized by fourier transform infrared spectrometer(FTIR), high performance liquid chromatography(HPLC), dynamic mechanical analysis(DMA) and laser diffuse scattering(LDS), the reactivity of the reactive emulsifier, the adhesive bonding properties and water resistance of PSA were investigated. The results indicate that the reactive emulsifier has been reacted to a large degree and it has a great effect on the properties of PSA. In addition, the PSA synthesized by reactive emulsifier have a better water resistance than that of traditional PSA.The influence of polymerization condition, reactive emulsifier and other reactants on the properties of emulsion system and PSA were researched through orthogonal design and single factor analysis. By discussing the polymerization specificity of acrylic monomers, vinyl acetate and the influence of reactive emulsifier on the water resistance of PSA, we assure the optimal formula: 1) for quaternary system, BA 83%, AA 1%, HEA 1%, VAc 15%, HS-10 0.3%, 2) for quinary system, BA 78~78.5%, AA 0.5%, HEA 1~1.5%, blends monomer20%(the dosage rate of MMA to EHA is 0.4), HS-10 0.3 %.The testing results of PSA water resistance indicate that the water resistance of PSA gained by HS-10 is better than that of traditional PSA. The water absorption rate can be reached the saturation value in a few seconds. The maximum of quaternary is 5.5% at 0.3% of emulsifier dosage, and for quinary is 4.9% at 0.3% of emulsifier. The water resistance of quinary system is better than quaternary system.The character groups of the pressure sensitive adhesive after etching were characterized by FTIR. Combining the HPLC testing of pure emulsion and etching emulsion with FTIR, we can conclude that the reactive emulsifier has been reacted and the conversion rate is up to 99.4% in quaternary system, and 98.9% in quinary system.In order to realize the dynamic mechanical properties of polymer, temperaturescan and frequency scan were used to determinate the loss modulus, storage modulus and Tan 5 . The results indicated that Tg of quaternary PSA is about — 27 °C, the modulus of polymer is changed a lot at low temperature, but when the polymer is changed to viscosity flow state at high temperature, the modulus are nearly not influenced by temperature. Combining DMA results with the data of mechanical properties analysis, it can be concluded that the PSA gained by reactive emulsifier have a better properties. The results of frequency scan tell us that the modulus of polymer increases as the frequency increases, the Tan 8 is conversed at nearly lOHz, and the PSA gained by reactive emulsifier is more sensitive to frequency. For quaternary system, when the frequency is lHz, G', G" and Tan 6 are at the value of 37730Pa, 13580Pa and 0.36 for PSA gained by reactive emulsifier and 43160Pa, 18560Pa and 0.43 for traditional PSA. When the frequency is lOOHz, G', G" and Tan 6 are at the value of 97490Pa, 58960Pa and 0.60 for PSA gained by reactive emulsifier and 121000Pa, 86600Pa and 0.72 for traditional PSA. While in quinary system, the data of G1, G" and Tan 6 are 45930Pa, 17520Pa and 0.38 for PSA gained by reactive emulsifier and 52960Pa, 24520Pa and 0.463 for traditional PSA at lHz of frequency. When frequency is lOOHz, the data of G', G" and Tan 5 are 122000Pa, 81880Pa and 0.67 for PSA gained by reactive emulsifier and 124000Pa, 207000 Pa and 0.7 for traditional PSA.