Exploration Of New Monomers For Modified PBO With Imidazole-group And Preliminarily Industrial Design Of 1,2,4,5-tetra Aminobenzene Hydrochloride

Poly(p-phenylene-2,6-benzobisoxazole)(PBO),as a new-type super fiber,possesses merits of extremely high strength,modulus,heat and fire resistance,has been widely concerned and become a hot spot in research field of high performance fiber materials.Whereas,due to weakness in resistance of light aging and pressure,along with the expensive raw material of monomer,the pace of its industrialization is hindered.In the paper,we aim at modifying the monomer with imidazole structure and chemical group to enhance some specific performance of PBO material.Firstly,with 4,6-dinitro-dichlorobenzene from m-dichlorobenzene(DCB)as raw material,the 1,2,4,5-tetraaminobenzene hydrochloride(TABH)was obtained after aminolysis and hydrogenation which occured in autoclave,then the DT complex salt was provided by 2,5-dihydroxyterephthalic acid(DHTA),thus the raw PDBI silk was gotten in subsequent polymerization and spinning,and effectively improved the surface cohesiveness of PBO materials.Secondly,with 2,6-dichlorotoluene(DCT)as starting materials,2,3,5,6-tetraaminotoluene hydrochloride(TATH),which is the imidazolemodified PBO monomer and could provide modified PBO fiber in subsequent synthesis prosess,was obtained through nitration,aminolysis and hydrogenation.In addition,the synthesis of precursor of PBO monomer was also explored,but the yield and purity of product need to be optimized in the latter part.Finally,the output of 500 t TABH product per year was primarily designed,mainly including material balance,major equipment selection and preliminary treatment plan of three wastes,the purity of final product is 99.34%,the overall yield is 63.91% by taking initial material of DCB as the base,and the gross profit could be up to 40.953 million RMB per year.