Research And Application Of Organic Lithium Process Safety

Organometallic compounds are indispensable catalysts in organic synthesis,which are characterized by wide application,high efficiency and cleanness.Among them,alkali organometallic compounds have high activity,which can quickly drive the reaction,especially in the field of synthetic rubber.Lithium metal is a very active alkali metal,and its corresponding organic lithium compounds are easy to prepare and can be dissolved in inert solvents.At the same time,China is rich in lithium resources,ranking first in the world.As the most important organic lithium compounds,butyllithium occupies a very important low position in polymer polymerization.There are four isomers in butyl lithium.In the field of synthetic rubber,most of them choose secondary butyllithium and n-butyllithium.Secondary butyllithium has high activity,but its thermal stability is poor and it is easy to be inactivated in the synthesis process,which brings great challenges to industrial production Butyllithium has excellent thermal stability,stable reaction process and long storage time.It is a good choice of initiator in the field of synthetic rubber.Liquid isoprene rubber is an organic lithium-based catalyst.It adopts anionic living polymerization method to polymerize isoprene monomer in a non-polar system.After post-treatment processes such as devolatilization and drying,liquid polyisoprene with excellent performance is obtained Diene rubber.The development of polyisoprene liquid rubber in recent years shows that liquid rubber synthesized by lithium-based initiators can be used in polymers such as ordinary solid rubber and plastics,and it can act as a modification assistant or filler to improve product performance..On the other hand,it can also be used as a prepolymer or basic raw material for the preparation of elastomers.It can not only improve the mechanical properties,resistance to solvent extraction,thermal stability and other physical and mechanical properties of rubber materials,improve the adhesion of rubber to metals or non-metals,but also improve the processing technology of rubber mixing,extrusion,calendering and vulcanization Performance,while also meeting the application requirements of modern military products.In this paper,the safety analysis of the organolithium polymerization process was carried out,and the safe operation rules of n-butyllithium were formulated.Using n-butyllithium as the initiator,anionic living polymerization method was used in hexanesolvent to explore the low molecular weight polyisocyanate.The preparation conditions of liquid rubber(LIR)were successfully prepared with low molecular weight and high cis polyisoprene liquid rubber,and the combustion characteristics of different molecular weight LIR were investigated.The results showed that the molecular weight increased by1000,the p HRR increased 10w/g,the calorific value increases about 5000J/g.Using tetrahydrofuran(THF)as a polarity modifier,LIR with different microstructures were prepared.To obtain high yields,the requirements for polymerization under conditions of changing polarity were explored.The kinetics of the reaction was explained and the polarity was analyzed.The effect of the change on the polymerization structure of the monomer was studied,and the capabilities of 1,4-structure and 3,4-structure in the energy release of combustion were studied.The results showed that for every 5%increase in 3,4-structure,the HRR value increased by 36W/g,The calorific value increases by 10000J/g.