Synthesis And Modification Of Dimer Acid Polyamide Hot Melt Adhesive

Dimer acid polyamide hot melt adhesive with the characteristics of adhesive quickly, non-toxic and good adhesive to polarity material that has a good application prospect in industry. This paper used dimer acid and ethylenediamine as the main raw material to synthetic a basic dimer acid polyamide hot melt adhesive and introduced the synthesis reaction principle, synthetic method and technological process of dimer acid polyamide hot melt adhesive. Using IR spectra to analysis the structural of product, using DSC and TG analysis the thermal performance of product. Results showed that the basic dimer acid polyamide hot melt adhesive has good thermal stability. Analyzed the influence of polymerization temperature to the viscosity, softening point of the product, tensile strength and other performance. The best polymerization temperature is 240℃, under optimum temperature its softening point is 105℃,viscosity is 830 mPa?s(190℃), and the tensile strength is 8.84 MPa.For the basic dimer acid polyamide hot melt adhesive has disadvantages on softening point, viscosity and mechanical properties, sebacic acid and piperazine were used to modify the product. This paper introduces the principle of modification, and examines the sebacic acid dosage on the properties of modified dimer acid polyamide hot melt adhesive, it is concluded that the optimum dosage of sebacic acid is 0.5 mole ratio of dimer acid dosage. The performance of the modified dimer acid polyamide hot melt adhesive was tested under the optimal quantity, and its softening point temperature is 145℃, the viscosity is 3886 Mpa?s(190℃), the tensile strength is 15.24 MPa. Compared with the basic dimer acid polyamide hot melt adhesive synthesis in the second chapter, the performance of modified products in viscosity, softening point and tensile strength had improved greatly. Modified dimer acid polyamide hot melt adhesive has better performance.The fourth chapter is an extend experiment and the blending method was used, with dimer acid, sebacic acid, piperazine and ethylene diamine as the raw materials to synthesis dimer acid polyamide hot melt adhesive, examined the effects of dimer acid dosage and piperazine dosage to performance of the product, and infrared spectrum was used to of the characterize the product. The results showed that with the mole fraction piperazine changed from 10.5% to 35.5%, Tg and softening point temperature of the product reduced and the tensile strength decreased. With the mole fraction of dimer acid changed from 35.5% to 40%, Tg and softening point temperature of the product gradually reduced, the tensile strength decreased too.