| As we all know, as the reinforced material of rubber composites, polyester fabrics have been widely used in rubber tire, conveyor belt and other fields with its excellent heat resistance, dimensional stability and other characteristics. But because of the inactive chemical property of PET, its tight structure and lustrous surface and good handle, its lack of polar groups, they lead to the poor interfacial adhesion effect between PET and rubber. Thus, the expansion of polyester application market is restricted. The main research direction of this topic is to improve the adhesion property between cloth layers of PET reinforced composites.This topic has synthesized four resol resins with different mole ratio of resorcinol/formaldehyde (1:1.3,1:1.5,1:1.7,1:2). Then verify that if the phenolic resin is completely synthesized through’ammonia detection’.Afterwards, prepare the resite by resol resins under heating condition. The property of phenolic resin with different mole ratio of resorcinol/formaldehyde has been analysed by infrared spectrum, TG and DSC etc. The results showed that, when the mole ratio of resorcinol/formaldehyde is 1:2, phenolic resin quickly loses weight in the initial steps and has poor heat resistance. When the mole ratio of resorcinol/formaldehyde is 1:1.3, the phenolic resin,which has lower decomposition temperature and is easier to decompose, cannot meet the requirement of melting at a specific temperature (325℃).Phenolic resin maceration extract (RFL) is obtained by mixing the series of resol resins and butadiene-vinylpyridine copylymer latex. Then we research the optimal process of preparing RFL film through changing pre-drying temperature, pre-drying time, baking temperature and baking time. And also finish the film’s preparation. We can draw a conclusion, the optimal process of preparing RFL film is that the pre-drying temperature is 120 degrees centigrade, the pre-drying time is 40 minutes, the baking temperature is 170 degrees centigrade, the baking time is 20 minutes. Next, the composition and flexibility of films has been analysed by its hardness, tensile strength, elongation at break and spectrum analysis etc. We can reach a verdict from the results finally. When the mole ratio of resorcinol/formaldehyde is 1:1.7, the tensile strength of phenolic resin is the highest while the elongation at break is the least. It is not easy to cause deformation and has moderate hardness. In a word, its comprehensive performance is optimal.Polyester fabrics which is being functional finishing by RFL should be drying. Then it is compounded with rubber in the form of two pieces of cloth and three pieces of rubber. We prepare the PET reinforced composite by heating, pressing and curing. According to the requirement of GB/T 31334.1—2015, we have tested the PET reinforced composite’s adhesion strengh under high temperature and normal temperature. The adhesion strengh under high temperature and normal temperature is both the highest when the mole ratio of resorcinol/formaldehyde is 1:1.7. Because of the rising temperature, the movement between molecules is even more intense. Interaction force between molecules is reduced and some chemical bonds are breaking. It leads to the damage of adhesion interface between PET and rubber. Thus, the high temperature’s adhesion strengh decreases to some extent comparing to the normal temperature’s adhesion strengh.In summary, we should select the resol resin with the mole ratio of resorcinol/formaldehyde is 1:1.7. Then mix the resol resin and butadiene-vinylpyridine copylymer latex into RFL which is used to polyester fabrics for functional finishing. The series of handling to PET can make it flexible and heat-resisting at the same time. Thus, we can improve the adhesion property between polyester and rubber. The PET reinforced composite also has certain flexibility and can melt at a specific temperature.When the phenolic resin applied to the conveyor belt, it can meet the production requirements of strength, flexibility and adhesion property between cloth layers. |
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