The Study Of The Synthesis Of Styrene-butadiene Latex With High And Low Temperature Composite Technology

At present, construction of highways, airports, Bridges is increasingly using asphalt pavement, but the shortcomings of matrix asphalt, such as high temperature sensitivity, poor ageing resistance, unable to bear high temperature and low temperature environment, etc. resulting in poor pavement material effect, appear the phenomenon such as damage, cracking, rutting within the design service life, ordinary asphalt has been difficult to meet the requirements. Therefore, it is necessary to optimize the performance of asphalt. The most commonly used modifier is polymer materials, they can give asphalt the better low temperature ductility and high temperature resistant performance. The styrene-butadiene latex has simple production process, high degree of industrialization, the preferable modification effect, so is widely used to modify asphalt.Through the exploration of polymerization process, we synthesized the high temperature and low temperature styrene-butadiene latex respectively through emulsion polymerization unit, and used in modified asphalt performance testing. The experimental results show that different styrene-butadiene latex make imparity influence on the modified asphalt. The styrene-butadiene latex synthesized at high temperature more improves asphalt softening point, accordingly the styrene-butadiene latex synthesized at low temperature more improves asphalt ductility. Compound use of two kinds of latex, with the change of latex content, the impact on the modified asphalt also is different.Synthesis of styrene-butadiene rubber latex with high and low temperature composite technology, the basic condition and formula after optimization:theory of solid content is 60%, St:Bd=30:70, low-temperature section reaction temperature 8?, high-temperature section reaction temperature 45 ?, from 8 hours began to heat up, total reaction time for 12 hours. Used in the modified asphalt performance test, it can improve the asphalt at low temperature and high temperature performance at the same time. Explores the method of two pieces of various conditions on the polymerization conversion and the effect of modified asphalt performance, mainly examines the temperature, time, chain transfer agent and initiator on the polymerization reaction. After completion of the process optimization, high solid content of styrene-butadiene rubber latex was synthesized by the complex technology, after removal of residual monomer, without concentration treatment, the solid content has reached 54%.Analyzed the performance of latex impact on the modified asphalt, mainly discusses the effect of combination of styrene content and gel content. The experimental results show that: Raise content of rubber latex gel and styrene can improve asphalt high temperature resistant performance. When latex is added an amount of 3% by mass of asphalt, modified 90# asphalt softening point increased to 52.2?,5 ? ductility more than 150 cm, and has very good strength. The performance of styrene-butadiene rubber latex is close to imported products and it can be used for industrial production.