| The compatibilities between SIS,SBS and various accessory ingredients are firstly researched. And based on that, the main materials for preparing SDS Hot-melt Pressure-sensitive Adhesive(HMPSA) are decided. And the most appropriate formulation for preparing SDS HMPSA is determined after considering important performances of 180°racking strength,initial adhesion,etc, by the method of Orthogonal design.For block copolymer PSA, the intermingling of various molecules of accessory ingredients changes the micro phasal structure of block copolymer, thereby initial adhesion and plasticity are bestowed. Using SIS/SBS polymer blend as parent meterial, SIS/SBS polymer blend and the transformation of phasal structure and rheological property of it after being blended with various accessory ingredients are studied. The result indicates that, SIS/SBS still possesses segregative hard and soft phasal structure after blending; polystyrene of different polymerization degree blend to the level of molecules; while in the phase of rubbery state, PB phase with solution of PI molecules and pure PI phase appear, and the system still possesses good mechanical property after blending; After the blending of SIS/SBS and tackifier, the system yet preserves distinct segregative biphasal structure, tackifier does not resolved in the hard phase of polystyrene,but resolved very well in the PB/PI phase, which makes the original phase in rubber state separate and the structure collapse, then become a single phase; After the blending of SIS/SBS with naphthenoid oil and PIB respectively, the separate phasal structure in the soft phase can not be uniformed by the two kinds of plasticizer, so the biphasal separate structure is maintained in the rubber state. And the plasticization- efficiency of softener oil is higher than that of naphthenoid oil.However, the interface of soft and hard phasal will be made undistinguishable.The adhesion and peeling is a dynamic process,which is a typical macromolecule rheology behavior. In application of PSA, the molecular motion and coherent structure both could be reflected on the change of rheology behavior. Based on the most optimal formulation from Orthogonal design with the understanding of polyphase-topological structure,the influences of various accessory ingredients to rheological property of PSA in the range of linear viscoelasticity are studied through the test of dynamic viscoelasticity: as the dosage of the three accessory ingredient increases, initial adhesion of PSA and 180°racking strength both increase first and then decrease. The mechanics are different from the three aspects of difficulty of molecular motion, the transformation of phase state and the time of molecular chain effecting on external force, frequency response.For the difference in mechanical property between acrylic emulsion and hot melt pressure-sensitive adhesive(PSA), the rheology behaviors of the two PSAs were studied. They were characterized by dynamic-viscoelastic frequency-scanning technique in the range of adhesion frequency (0.01 Hz) to peeling frequency (100 Hz). The results indicated that storage modulus (E′), loss modulus (E″), loss factor (Tanδ) and viscosity (η) have a great difference between acrylic emulsion and hot melt PSA, and these characteristics showed different transformation rules. Conclusions can be drawn considering the experimental results based on polymer rheology theory that low polymer storage modulus leads to great initial adhesion under the adhesion frequency (0.01 Hz),and polymers with high value of storage modulus have great sustained adhesion, and those with great values ofη,E′give long sustained adhesion time under the peeling frequency(100Hz).
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