Effect Of Acetone Extract On Ozone Aging Properties Of Rubber

Natural rubber(NR)has excellent comprehensive performance.In addition to structure,the types and content of non-rubber substance from natural rubber affect the nature of the rubber and properties of vulcanized rubber.However,there are a large number of double bonds in the molecular chain and NR is easy to react.Ozone cracking break the rubber product and loses its use value.The main chain structure of isoprene rubber(IR)is the same as NR,so the ozonation reaction of IR is similar to NR.This paper adopt the new processing technology,the microbiological coagulation and airing to prepare purified natural rubber and acetone extract was extracted from skim rubber by dissolution of acetone.Acetone extract influence on the vulcanization performance,crosslink density,mechanical properties and properties of resistance to ozone aging were studied under purified natural rubber,natural rubber and isoprene rubber.On this basis,the changes of functional groups of purified natural rubber before and after ozone aging were studied.The results of vulcanization performance shows that the T90 of NR shorten significantly and the degree of cross-linking increase when acetone extract has reasonable added amount;however,the degree of cross-linking decrease of IR.The T90 and T10 of IR descend slightly due to the fact that the isoprene rubber is not contain non-rubber substances.The addition of acetone extract can improve the vulcanization performance of rubber with different level.Crosslink density test indicated that the crosslink density increase of NR with acetone extract,so the mechanical properties increase of NR.The tensile strength of purified NR increase by 33.36%compare to the blank sample when 2.5g acetone extract was available.If 1.5g acetone extract was added,the tensile strength of NR go up by 11.59%compare to the blank sample.Acetone extract can improve the crosslink density and mechanical properties of IR when the content of acetone extract is less than 1.5g;however,the crosslink density and mechanical properties reduce with the increase of acetone extract when the content of acetone extract is more than 1.5g.It can be concluded from properties of resistance to ozone aging test that the retention of tensile strength of purified NR is highest by 49.74%and the cracking time is longest when 2.5g acetone extract was available.If 1.5g and 0.5g acetone extract was added,respectively,the retention of tensile strength and the cracking time of NR and IR are the best,showing excellent ozone resistance.Acetone extract can ameliorate the thermal stability of rubber when it has reasonable added amount.FTIR analysis indicated that acetone extract participate in the anti-aging ozone reaction of purified NR.It can be seen from DSC test that the glass transition temperature increase of NR with acetone extract.