【作者】 陈卫东；

【导师】 张鹏云；

【作者基本信息】 西北师范大学 ， 有机化学， 2011， 硕士

【摘要】 3,3′,5,5′-四甲基联苯二酚（TMBP）是一种重要的有机中间体,可用作聚酯﹑聚氨酯﹑聚碳酸酯﹑聚砜﹑环氧树脂等诸多产品的改性单体;也可用作橡胶﹑乳剂防老剂和塑料抗氧剂,以及染料中间体或石油制品的稳定剂。本实验提供了一种制备3,3′,5,5′-四甲基联苯二酚的新方法,即以2,6-二甲基苯酚为原料,在水介质中采用双氧水做氧化剂,通过氧化偶合反应和还原反应,两步法合成3,3′,5,5′-四甲基联苯二酚;另外还探讨了氧化剂和催化剂对产物收率的影响,经过反复实验得出最佳工艺条件为:2,6-二甲基苯酚:双氧水:催化剂=1:2:0.00018（摩尔比）,氧化偶合反应温度为80℃,氧化反应时间为3h,还原反应温度为80℃,还原反应时间为0.5h,产品产率和纯度分别可达80%和99%以上。此合成方法在工业中具有很好的应用前景。含联苯结构的环氧树脂是一种具有液晶性的环氧树脂,具有许多优异的性能。本文采用新的方法合成了环氧树脂改性单体-3,3′,5,5′-四甲基联苯-4,4′-二羟乙基醚;用三种方法合成了3,3′,5,5′-四甲基联苯二酚二缩水甘油醚,并对三种方法的反应步骤,原料,反应条件,产率和后处理进行了讨论;此外,还合成了4,4′-双（2-羟基乙基）-3,3′,5,5′-四甲基联苯二缩水甘油醚（BP1）和4,4′-双（4-羟基苯甲氧基）-3,3′,5,5′-四甲基联苯二缩水甘油醚（BP2）两种联苯环氧树脂。联苯结构的液晶是目前应用最广泛的一种液晶材料,本文以3,3′,5,5′-四甲基联苯二酚为原料设计并合成了八个对称联苯双酯类液晶化合物,它们的介晶性通过差示扫描量热仪（DSC）,X-射线衍射仪（XRD）和热台偏光显微镜（POM）进行了研究;并测定了4,4′-3,3′,5,5′-四甲基联苯-二（4-甲基苯甲酸酯）（Ⅲa）的单晶结构,结果显示:晶体属于单斜晶系,P2₁/C空间群,晶胞参数为a=18.525（3）（A|°）,b=12.196（2）（A|°）,c=12.195（2）（A|°）,（A|°）=97.142（2）°,V=2733.7（9）（A|°）³,Z=4,D_c=1.163 Mg/m³,R=0.0521, R_W=0.1161。化合物均为热致型互变液晶,并讨论了氧原子、不饱和端基和端基链长对介晶性的影响。更多还原

【Abstract】 3,3′,5,5′-tetramethyl-diphenol（TMBP） is an important organic intermediate of dye which can be used as modified monomers of polyester, polyurethane, polycarbonate, polysulphone, epoxy resin and so on. Also used for the stabilizer of rubber, emulsion, plastic and some petroleum products. This experiment provided a new synthetic route of TMBP. It was synthesized from 2,6-dimethylphenol by two-step method which are oxidative coupling and reduction reaction, hydrogen peroxide was used as oxidant in the water. The effect of oxidant and catalyst on product was studied, The optimum process was determined and was that 2, 6-dimethylphenol: oxydol: catalyst= 1: 2: 0.00018 （molar ratio）, the temperature and time of oxidative coupling are 80℃and 3h, the temperature and time of reduction reaction are 80℃and 0.5h, the yield and purity are above 80% and 99% respectively. The method is very useful from the industrial point of view.Epoxy resin containing biphenyl structure is a kind of liquid crystal epoxy resin. 3,3′,5,5′-tetramethyl-4,4′-di（2-hydroxyethanyoxy）-biphenyl as a modified monomer of epoxy resin was synthesized by a new synthesis method in this article. Also 3,3′,5,5′-tetramethyl- diphenyldiglycidyl ether was synthesized by three methods. Reaction steps, raw material, reaction conditions, yield and treatment processes of three methods were studied. Then two epoxy resins containing biphenyl structure were synthesized, They are 4,4′-bis（2-hydroxylethyl）-3,3′,5,5′-tetramethylbiphenyl（BP1） and 4, 4′-bis（ 4-hydroxybenzoyloxy ） -3,3′,5,5′-tetramethylbiphenyl （BP2）.At present biphenyl liquid crystals are widely used. Eight symmetrical diphenylnate liquid crystals were prepared from 3,3′,5,5′-tetramethyl-diphenol in this article. Their liquid crystal properties were tested by differential scanning calorimetry （DSC）, X-ray diffraction （XRD） and hot stage polarizing microscop （POM）. The crystal structure ofⅢa was detemfined by single crystal X-ray diffraction techniques,Ⅲa is a monoclinic crystal system, space group P2₁/C with the unit cell parameters: a=18.525（3）（A|°）, b=12.196（2）（A|°）, c=12.195（2）（A|°）,（A|°）=97.142（2）°, V=2733.7（9）（A|°）³, Z=4, D_c=1.163 Mg/m³, R=0.0521, R_W=0.1161. The results showed that molecules lead thermotropic liquid crystals properties. The relations among the mesomorphism, oxygen atoms, terminal unsaturated bond, the flexible chain length were investigated.更多还原