Preparation And Performance Of Modified EVA Hot-melt Sealant

Adhesive is widely used in every feild,such as construction,textiles,footwear,health care and so on.The hot-melt adhesives not only can cement,but also can be used to seal.This paper,which adopted the method of physical blending modification research,used EVA as the main component of the hot-melt adhesives and regarded these things such as:PE,PVC,TPU,auxiliary rosin and nanoCaCO₃ as modifiers,on the basis of exploring appropriate mixer temperature,time and revolution,to prepare a type of EVA hot-melt sealant.And then the tensile strength,elongation at break,modulus of elasticity,hardness and shear strength were tested by the electronic universal testing machine.The microstructure of the sealants were investigated by FTIR,TGA and SEM.EVA/PE,EVA/PE/138 rosin resin,EVA/PE/nanoCaCO₃ and EVA/PE/138 rosin resin/nanoCaCO₃ were blended by the Banbury Mixer in turn and in the course a certain amount of antioxidant 1010 and PEG6000 were also added,The blending temperature was 120?,rotationl speed was 30 rpm,time was 5 min.By analyzing the chemical properties,hardness and the microstructure of these four groups of mixture,the conclusion were as follows:The best ration of EVA:PE:138 rosin resin:nanoCaCO₃ was 14:6:3:2.3?mass ratio?;the tensile strength was 16.52 Mpa,the elongation at break was 821%,the shear strength was 3.54 Mpa,the shore hardness was 38 D;the thermal stability and compatibility were also improved.Above all,this mixture had the best comprehensive performance.EVA/PVC,EVA/PVC/138 rosin resin,EVA/PVC/TPU and EVA/PVC/138 rosin resin/TPU were blended by the Banbury Mixer in turn and in the course a certain amount of antioxidant such as 1010 and PEG6000 and thermal stabilizers were also added.The blending temperature was 110?,rotationl speed was 30 rpm,time was 5 min.By analyzing the chemical properties,hardness and the microstructure of these four groups of mixture,the conclusion were as follows:the best ration of EVA:PVC:TPU:138 rosin resin was 2:2:2:0.9?mass ratio?;the tensile strength was 16.14 Mpa,the elongation at break was 346%,the shear strength was 3.8 Mpa,the shore hardness was 40 D;the thermal stability and compatibility were also improved.Above all,this mixture had the best comprehensive performance.Eventually,comparing the comprehensive performance of the two types mixture of EVA/PE/138 rosin resin/nanoCaCO₃ and EVA/PVC/138 rosin resin/TPU,these conclusion were found that their tensile strength,shore hardness and shear strength were similar;The elongation of EVA/PE/138 rosin resin/nanoCaCO₃ was far better than the elongation of EVA/PVC/138 rosin resin/TPU;the thermal stability and compatibility of EVA/PE/138 rosin resin/nanoCaCO₃ was also better than the thermal stability and compatibility of the EVA/PVC/138 rosin resin/TPU.So for the modificartion effect,PVC was not as good as PE.