Green Flocculation Mechanism And Experimental Study Of Skim Rubber

Skim latex is a by-product of the centrifugation of fresh natural latex to produce concentrated latex.The particle size is small,the concentration is low,and the impurity content is high,resulting in a small amount of skim rubber and poor performance after flocculation.In order to speed up the flocculation speed and reduce the cost,sulfuric acid flocculation is commonly used at present,the obtained skim rubber has poor aging resistance,large amount of waste water and difficult post-treatment,and great environmental pressure.Therefore,researching an environmentally friendly flocculation method so that the performance of skim rubber can be equivalent to ordinary natural rubber is equivalent to increasing the output of natural rubber,while reducing the difficulty of post-treatment of wastewater,enabling the production process to be environmentally friendly,and reducing cost of production.At present,it has become an urgent problem for the industry to solve.In this paper,three methods of electrophoresis,wet mixing and microwave-assisted carbon black flocculation are proposed to prepare skim rubber from skim.The effect of skim rubber used to prepare tire apex and its properties was analyzed,and the properties and application feasibility of the rubber compound were analyzed.The residual liquid produced after flocculation was tested for element content.The main work completed are as follows:（1）A method of preparing skim rubber from skim by electrophoresis was proposed,the electrophoretic flocculation mechanism of skim rubber was studied,and the difference between it and magnesium chloride and acetic acid flocculation mechanism was analyzed.Three groups of rubber compounds were tested for performance using the basic formula.The test results shown that compared with the other two processes,the skim rubber flocculated by electrophoresis has the best aging resistance and abrasion resistance,and the abrasion resistance is 16.31% and 8.45%higher than that of skim rubber flocculated by magnesium chloride and acetic acid,respectively.（2）A method of replacing part of deionized water with skim latex to prepare carbon black/skim latex dispersion liquid,and using skim latex in wet mixing process was proposed,and the wet mixing mechanism of skim latex was studied.Tire apex with skim rubber content of 6,13,20,and 27 parts were prepared,and compared with the tire apex without skim rubber.The influence of blending skim latex on the properties of tire apex in the wet mixing process was analyzed by testing mechanical properties and vulcanization properties;The influence of different fractions of skim rubber added on the comprehensive properties of tire apex was investigated,and the optimal addition fraction of skim rubber was determined.The test found that with the increase of skim rubber content,the hardness of the tire apex increased.The hardness of the tire apex without skim rubber was 83.5,and the hardness increased to 89.5 after adding 27 parts of skim rubber;After adding skim rubber,the vulcanization speed of tire apex is increased by about 5.5%;The carbon black of tire apex with 27 parts of skim rubber added had the best dispersion.（3）A method of skim rubber flocculated by microwave-assisted carbon black was proposed,and the mechanism of the synergistic effect of microwave and carbon black was studied.The tire apex with 23 skim rubber flocculated by microwave-assisted carbon black,23 skim rubber flocculated by electrophoresis and skim rubber flocculated by electrophoresis as matrix were prepared,compared with the tire apex rubber prepared with Thai standard rubber,the feasibility of applying skim rubber flocculated by electrophoresis to the preparation of tire apex rubber in large quantities was analyzed.The test found that the hardness of the tire apex after adding 23 parts of skim rubber increased,the tensile stress increased by about 15%,and the aging resistance was improved;Among them,the thermal stability of the tire apex with 23 parts of skim rubber flocculated by electrophoresis was the best.（4）The residual liquid after electrophoresis and microwave-assisted carbon black flocculation was treated and the element content was tested,compared with the skim latex and tap water,and the influence of the two flocculation processes on the element content of wastewater was analyzed.It was found that the content of metal ions in the electrophoresis and microwave waste liquids was significantly lower than that in skim latex.