Synthesis And Characterization Of Novel Poly (Bisbenzoxazole)s And Polyamides Containing Xanthene Units

Industrialized poly(bisbenzoxazole)s and polyamides as the high performancematerials have been received much attention. But their hard-soluble and the difficultyof prcessing limited their use. In this paper, the design and preparation of newmonomers in the polymer chain is to introduce a large volume of Cardo-type xantheneunits, aims to prepare two types of polybenzoxazole and polyamide containingxanthene. The main skeleton of this dissertation contains four parts.1. Using9,9-bis(4-hydroxyphenyl)xanthene (BHPX) and concentrated nitric acid asmaterials to synthesis the intermediate9,9-bis(3-nitro-4-hydroxyphenyl)xanthene (BNHPX), then restore BNHPX to synthesis a novel bis(aminophenol)monomer-9,9-bis (3-amino-4-hydroxyphenyl) xanthene(BAHPX). The totalyield is80.4%. This method has the advantages of simple operation, mild reactioncondition and high yield.2. The new poly(bisbenzoxazole)s containing xanthene units were prepared fromBAHPX and a series of aromatic acids in poly(phosphoric acid)(PPA) and P2O5in an nitrogen atmosphere at high temperature. The polymers’ logarithmicviscosity ratio is between0.43-1.08dL/g. All of the poly(bisbenzoxazole)s showexcellent heat resistance,(461°C-555°C at5%weight loss and504°C-584°C at10%weight loss). They are all non-crystalline polymers. While maintaining theexcellent thermal properties also have good solubility. So these new polymerscould be considered as new materials.3. The reaction of9,9-bis [(3-methyl-4-hydroxy)phenyl]xanthene (BMHPX) andp-Nitro chlorobenzene is to produce an intermediate product-9,9-bis[(3-methyl-4-nitrophenoxy) phenyl]xanthene (BMNPPX), than using BMNPPX to prepare anew aromatic diamine monomer-9,9-bis[(3-methyl-4-aminophenoxy) phenyl]xanthene (BMAPPX), with a yield of91.1%. 4. Polymides containing xanthene units were prepared from BMAPPX,terephthaloyl chloride and isophthaloyl chaloride in DMAC in an nitrogenatmosphere at0°C. The yields of copolymers are higher than87%. Thecopolymers’ logarithmic viscosity ratio is between0.67-1.66dL/g. PAIs havegood solubility conducive to molding. They also show good thermal stability(413°C-437°C at5%weight loss and444°C-449°C at10%weight loss). Inaddition, PAIs’ films have high optical transmittance, the light transmittance atwavelength of500nm is between72.4-83.2%. Also, the copolymers showexcellent mechanical properties: The tensile strength of the polymer ranges from71.53-107.45MPa. The tensile modulus of the polymer is from1.73-2.71GPa.Elongation at break of the polymer ranges from3.33-9.07%. These newcopolymers could be considered as a type of high-strength materials.