【作者】 蒋文俊；

【导师】 杨绪杰； 陆路德； 汪信；

【作者基本信息】 南京理工大学 ， 材料物理与化学， 2009， 博士

【摘要】 本论文主要围绕无卤阻燃剂的制备以及其在热塑性高分子材料中的阻燃应用展开研究,具体内容如下:以三聚氰胺与甲醛为原料,甲醇为阻聚剂,三乙醇胺为pH值调节剂,合成出三聚氰胺甲醛树脂预聚体。以过硫酸钾（KPS）为催化剂,采用原位聚合法制备了微胶囊红磷（MRP）。结果表明,KPS的加入有助于提高三聚氰胺甲醛预聚体的反应活性,使三聚氰胺甲醛树脂有效地包覆在红磷（RP）表面,缩短了反应时间;且此时制备的MRP包覆效果最佳,其氧化反应峰温为480℃,较RP原料高,可使用范围宽。采用熔融挤出法制备了多组不同配方的聚丙烯（PP）复合材料。结果表明,当PP:MRP:氢氧化镁（MH）=100（phr）:15（phr）:50（phr）时,复合材料的极限氧指数（LOI）为26%,垂直燃烧达到UL-94标准的V-0级,且阻燃剂的加入对复合材料的拉伸强度影响很小。以硝酸铝、硝酸镁以及氢氧化钠为原料,采用共沉淀法制备硝酸根插层的层状双氢氧化镁铝（LDH-NO₃^-）。X射线粉末衍射（XRD）结果表明,LDH-NO₃^-的纯度与搅拌时间有关,随着搅拌时间的增加,产物中的杂质峰逐渐减弱;当搅拌时间为100min时,杂质峰完全消失。在制备LDH-NO₃^-的基础上,选用硬脂酸钠(C₁₈H₃₅O₂Na)改性LDH-NO₃^-。通过XRD表征发现,当n(C₁₈H₃₅O₂Na)/n（Al）=1时,C₁₈H₃₅O₂^-插层效果较好,层间距由0.80nm增加到2.98 nm。热重与差热分析（TG-DTA）结果显示,以硬脂酸钠改性的LDH热稳定性良好。采用熔融挤出法制备了多组不同配方的尼龙6（PA6）复合材料。结果表明,当PA6:LDH:MRP=100（phr）:9（phr）:9（phr）时,复合材料的LOI为28.5%,垂直燃烧达到V-0级,且阻燃剂的使用不影响复合材料的拉伸性能。以硝酸铜、钼酸钠以及氢氧化钠为原料,采用沉淀法,在较低的温度下制备出片状一水合二钼酸三铜（CMH）。结果显示,合成的CMH为（50～100）nm宽、（100～300）nm长的片状结构材料,且结晶性好,并具有很好的耐热性,起始分解温度达到320℃左右,能满足普通塑料的加工要求。采用熔融挤出法制备了多组不同配方的乙烯-醋酸乙烯酯共聚物（EVA）复合材料。结果表明,将CMH与MRP或MH复配使用时,能起到很好的协同阻燃作用。此外,当EVA:MRP:MH=100（phr）:15（phr）:60（phr）时,MRP/MH/EVA复合材料的LOI能达到为39%,且垂直燃烧为V-0级。以硫酸与高锰酸钾为氧化剂,磷酸为辅助插层剂,采用化学氧化法制备出具有高膨胀体积的可膨胀石墨（EG,粒径≤30μm）。XRD与扫描电子显微镜（SEM）结果表明,当硫酸与磷酸体积比为2:1时,氧化-插层效果最佳,膨胀体积达到102 mL·g^-1。X射线能谱（EDS）分析与傅立叶变换红外（FTIR）光谱分析显示,EG片层中可能插入了磷酸、硫酸以及Mn的磷酸二氢盐与硫酸盐等物质。TG-DTA结果表明,EG的起始膨胀温度应在160℃左右。采用熔融挤出法制备了多组不同配方的高密度聚乙烯（HDPE）复合材料。结果表明,当HDPE:MRP:MH:EG=100（phr）:15（phr）:35（phr）:5（phr）时,MRP/MH/EG/HDPE复合材料的LOI为28.5%,垂直燃烧能达到V-0级,且阻燃剂的加入对复合材料的拉伸强度影响不大。以氯化镁和氢氧化钠为原料,尿素为络合剂,采用反沉淀法制备了高纯片状氢氧化镁。XRD与EDS结果表明,当氯化镁浓度达到2 mol·L^-1时,就有杂质生成;使用尿素后,杂质会减少。当尿素量为30 g·L^-1时,杂质完全消失,此时制备的氢氧化镁为（30～120）nm的片状材料。以硬脂酸钠为改性剂,制备出改性氢氧化镁（MH）。结果显示,当硬脂酸钠用量为5%（wt）时,改性效果最好,与改性前相比,其形貌仍为片状,且粒径变化不大。采用熔融挤出法制备了多组不同配方的尼龙66（PA66）复合材料。结果表明,改性氢氧化镁（MH）与PA66的相容性很好,且少量MRP或MH的加入不会影响PA66复合材料的拉伸强度。当PA66:MRP:MH=100（phr）:10（phr）:8（phr）时,MRP/MH/PA66复合材料的垂直燃烧为V-0级,LOI能达到32%。更多还原

【Abstract】 In this contribution,several halogen-free flame retardants have been prepared,and their flame-retardant application in the thermoplastic polymers has also been studied.The main contents are as follows:The melamine-formaldehyde prepolymer has been first synthesized using melamine and formaldehyde as raw materials,methanol as inhibitor and triethanolamine as pH value regulator.Subsequently,the microencapsulated red phosphorus（MRP） has been successfully prepared by in-situ polymerization using potassium persulphate（KPS） as initiator.It is found that KPS is useful in enhancing the reaction activity of the melamine-formaldehyde prepolymer,which can encapsulate well on the red phosphorus by the melamine-formaldehyde prepolymer and reduce the reaction time.The differential scan calorimetry（DSC） curves show that the peak temperature of oxidation reaction for MRP is 480℃,which is higher than that of RP,extending the applications for MRP.Polyproplene（PP） composites with different formulations have been prepared by melt extrusion.It is shown that if PP:MRP:magnesium hydroxide（MH）=100（phr）:15（phr）:50（phr）,the limited oxygen index（LOI） of the composite is 26%,vertical firing ranking UL-94 V-0,and the use of flame retardants has less influence on the tensile strength of the composite.LDH-NO₃^-has been prepared by coprecipitation method using Al（NO₃）₃·9H₂O,NaOH and Mg（NO₃）₂·6H₂O as raw materials.The X-ray diffraction（XRD） results show that the purity of LDH-NO₃^-has a good relationship with the stirring time,and the intensities of impurity peaks for the resulting products decrease as the stirring time increased and almost disappeared when the reaction time reaches 100min.C₁₈H₃₅O₂Na has been used to modify LDH-NO₃^-.It is shown that when the ratio of C₁₈H₃₅O₂Na/Al（NO₃）₃·9H₂O is 1,the quantity of C₁₈H₃₅O₂^-intercalated into the interlayer of LDH almost gets the maximum.Compared with the LDH-NO₃^-,the interlayer spacing of LDH is increased from 0.80 nm to 2.98 nm.The LDH modified with C₁₈H₃₅O₂Na has a good thermal stability.Nylon-66（PA66） composites with different formulations have been prepared by melt extrusion.The results indicate that when PA6:LDH:MRP=100（phr）:9（phr）:9（phr）,the limited oxygen index（LOI） of the composite is 28.5%,vertical firing ranking V-0,and the use of flame retardants has no influence on the tensile property of the composite.The sheet-like Cu₃（MoO₄）₂（OH）₂（CMH） powder has been prepared at lower temperatures by precipitation method using Cu（NO₃）₂·3H₂O,Na₂MoO₄·2H₂O and NaOH as raw materials.The results show the obtained CMH powders are sheet-like and well-crystalline with 50～100 nm width and 100～300 nm length.The CMH powders also have a good thermal stability,and its initial decomposing temperature reach around 320℃, which can satisfy machining requests of common plastics.Poly（ethylene-co-vinyl acetate） （EVA） composites with different formulations have been prepared by melt extrusion.It is indicated that there is good synergistic effect between CMH and MRP（or MH）.In addition, when EVA:MRP:MH=100（phr）:15（phr）:60（phr）,the limited oxygen index（LOI） of the MRP/MH/EVA composite is 39%and vertical firing rankes V-0.The expendable graphite（EG） particles with the size of≤30μm and high expanded volume have been prepared by chemical oxidation method with H₂SO₄ and KMnO₄ as oxidant, H₃PO₄ as assisted intercalation agent.The XRD and scanning electron microscopic（SEM） results show that when the volume ratio between H₂SO₄ and H₃PO₄ is 2:1,the oxidation and intercalation effectiveness will be best,and the expanding volume gets to 102 mL·g^-1.The energy dispersive X-ray spectrum（EDS） analyses and the Fourier transform infrared（FTIR） spectra indicate there could be H₃PO₄,H₂SO₄,dihydric phosphate and sulphate containing Mn in the layers of EG.It is also demonstrated that the initial expanding temperature of EG is about 160℃through TG-DTA curves.High density polyethylene（HDPE） composites with different formulations have been prepared by melt extrusion.The studies reveal that when HDPE:MRP:MH:EG-100（phr）:15（phr）:35（phr）:5（phr）,the limited oxygen index（LOI） of the MRP/MH/EG/HDPE composite is 28.5%,vertical firing ranking V-0,and the use of flame retardants has less influence on the tensile strength of the composite.High purity MH powder has been prepared by precipitation method with MgCl₂·6H₂O and NaOH as raw materials,CO（NH₂）₂ as coordination agent.The XRD and EDS results show the impurity could generate when the concentration of MgCl₂ reaches 2 mol·L^-1.Unless CO（NH₂）₂ is used,it would not decrease.After the concentration of CO（NH₃）₂ gets to 30 g·L^-1,the impurity disappears and the obtained MH powder is lamellas with the size of （30～120） nm.The MH particles have been modified with C₁₈H₃₅O₂Na.It is revealed that the modification effect could be best when the usage of C₁₈H₃₅O₂Na reaches 5%（wt）.Comparing with pre-and post modification,the morphology and the size of MH almost have no change. Nylon-66（PA66） composites with different formulations have been prepared by melt extrusion.The results indicate the modified magnesium hydroxide has a good compatibility with PA66,and small quantity of MRP or MH almost has no influence on the tensile strength. As PA66:MRP:MH=100（phr）:10（phr）:8（phr）,the limited oxygen index（LOI） of the composite is 32%,and vertical firing ranksV-0.更多还原