| Rubber film is one of the core components of gas regulator,which is related to gas safety.The requirements of such products are high strength,good elasticity and thin thickness(<0.5mm).Domestic film products are often thick(>1.0mm),with short life and low sensitivity of regulating pressure,which is difficult to meet the requirements,leading to the use of imported rubber film in major cities in China.How to control the processing rheology and the relationship between the thickness of the rubber film and the mechanical properties(strength/elasticity)is the key technology in the research and development of ultra-thin rubber film.This study starts with the rheological properties of the rubber,the relationship between the formula and the properties of the rubber,the Mooney viscosity of different rubber,viscosity resin,reinforcing filler,sulfur and the type and amount of accelerator and the fabric treatment agent on the properties of the rubber and the properties of the film.The main research contents and results are as follows:The rheological properties and mechanical properties of vulcanized rubber were controlled by three kinds of NBR with Mooney viscosity of 33,52 and 79,coumarone resin and phenolic resin(PF).The results showed that when the Mooney viscosity of 33and 52 was 20/80,the rheological properties of the rubber were better than other ratios,and the mechanical properties were the best.The effect of raw rubber used on the rheological properties was much greater than that on the mechanical properties of vulcanized rubber,which indicated that the influence of the molecular weight and distribution of raw rubber on the properties of vulcanized rubber was much lower than that of crosslinking.With the same amount of PF,the Mooney viscosity,shear viscosity and Payne effect of the rubber were all lower than those of the corresponding coumarone resin.When the amount of PF increased from 0phr to 20phr,the tensile strength of rubber increased from 12.8MPa to 17.2MPa,but the resilience decreased from 31.1%to10.5%.Coumarone resin had little effect on the tensile strength and resilience of vulcanized rubber.When the total amount of the two resins was 15phr and the blend ratio of coumarone resin and phenolic resin was 10/5,the comprehensive mechanical properties of NBR rubber were the best.The effects of carbon black(N330),Si O2,nano-kaolin and illite on the rheological properties and the mechanical properties of rubber were studied.The results showed that the four fillers all increased the viscosity and the mechanical properties of rubber.The viscosities,Payne effect and the mechanical properties of rubber were significantly improved by Si O2.The tensile strength of vulcanized rubber was increased from 6.2MPa to 20.6 MPa by Si O2 at 30phr,but the resilience decreased from 24.8%to 18.3%.The reinforcing property and viscosifying action of carbon black were in the middle.Nano-kaolin and illite had a slightly lower reinforcing property.When the dosage of nano-kaolin and illite was 30phr,the tensile strength of rubber was increased to 14.5MPa and11.5MPa,but they had little effect on the Mooney viscosity and resilience.Different sulfur(S)and accelerator(NS,TMTD)ratios were used to control the curing properties and mechanical properties of the rubber.The results showed that when the dosage of S and NS changed from 2.5phr and 1.0phr to 0.5phr and 3.0phr,the scorch time decreased firstly and then increased,the vulcanization rate increased firstly and then decreased,the mechanical strength and Payne effect of vulcanized rubber decreased,and the elongation at break and resilience of vulcanized rubber increased.TMTD could accelerate the vulcanization rate,but the dosage of TMTD also affected the properties of vulcanized rubber.The rubber film was prepared by double-sided laminating process and its properties were tested.The results showed that the imported rubber film(0.4mm)had a tensile strength of 29.6MPa and an elongation at break of 21.7%;Domestic rubber film(1.0mm)had a tensile strength of 11.2MPa,and an elongation at break of 12.3%;The experimental rubber film(0.5mm)had a tensile strength of 22.5MPa and an elongation at break of more than 22%.The quality change rate of the experimental rubber film in solvent resistance test was lower than that of imported and domestic film.The surface of the reinforced fabric was treated with NBR latex,isocyanate and Si-69 respectively.It was found that the peel strength of the rubber film was increased from21.60N/25mm to 35.50N/25mm after the impregnation of NBR latex.The peel strength of the rubber film was significantly improved after the impregnation of isocyanate,which was impossible to measure.However,the impregnation of Si-69 had little effect on the peel strength. |
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