光固化阻燃单体、树脂合成及其阻燃机理研究

本文综述了过去十余年间中国科技大学施文芳教授研究组在光固化阻燃技术领域的工作成果，主要包括活性单体、稀释剂、光固化树脂配方等体系，品类有磷酸酯类单体、含磷丙烯酸酯、超支化丙烯酸酯树脂、膦酸酯类单体和树脂、丙烯酸化环状磷腈、甲基丙烯酸化三聚氰胺、含磷环氧单体等十余种。同时介绍了这些配方体系的合成、性能和应用方法，以及对其热降解、阻燃性能评价和阻燃机理的研究。     

POP-290阻燃剂对丙烯酸酯光固化涂料的影响

制备了双酚A环氧丙烯酸酯(EA)/阻燃剂(POP-290,聚合物聚醚多元醇)/活性单体阻燃UV涂料,主要考察了不同用量的阻燃剂对丙烯酸酯UV涂料的阻燃性能和光固化的影响.研究结果表明,阻燃剂的使用提高了UV涂料体系的固化速度、凝胶含量及玻璃化转变温度(T_g).当m(EA):m(活性单体)=4:1,POP-290含量为7%(质量分数)时,水平燃烧等级达到FH-1,LOI从原来的21提高到26.     

含烯丙基六苯氧基环三磷腈的合成及其在阻燃丙烯酸酯树脂中的应用

以六氯环三磷腈（HCCP）、苯酚和2-烯丙基苯酚为原料,合成了新型含烯丙基的环磷腈阻燃单体（2-烯丙基苯氧基）五苯氧基环三磷腈（APPCP),用红外光谱、核磁氢谱、质谱和元素分析表征其组成和结构。 将APPCP与丙烯酸酯单体共聚制备了阻燃丙烯酸酯树脂,测试了共聚丙烯酸酯树脂的热稳定性和阻燃性,当APPCP用量为20%时,共聚丙烯酸酯树脂燃烧等级（UL-94）可达V-0级,极限氧指数（LOI）高达31.2%,在空气中600 ℃时残留质量提高至23.2%。     

光盘用2P胶应用研究进展

对光盘用２Ｐ胶的应用研究进展情况进行了评述，其中光盘制备用光聚合浮雕成型２Ｐ胶的基本组成为各类多官能团丙烯酸酯类单体；光盘保护涂层用２Ｐ胶主要组分为环氧丙烯酸酯类预聚体。     

含氟丙烯酸酯-苯乙烯共聚物的制备及其表面性能的研究

研究了聚合工艺、含氟丙烯酸酯类单体种类和用量、苯乙烯和自由基引发剂用量及硅烷偶联剂、催化剂等因素对含氟丙烯酸酯-乙烯共聚物表面性能的影响。结果表明：聚合工艺、含氟丙烯酸酯类单体种类和用量对共聚物表面的憎水性能有显著的影响;采用延时滴加含氟丙烯酸酯类单体可提高共聚物膜表面的憎水性;随含氟丙烯酸酯类单体侧链含氟烷基的链长和氟原子数及含氟单体用量的增加,共聚物水接触角增大,吸水率下降;共聚物薄膜的硬度则与含氟丙烯酸酯类单体中α-取代基、侧链含氟烷基的链长和用量、苯乙烯用量、引发剂浓度等相关;硅烷偶联剂和催化交联剂的加入可提高共聚物薄膜的强度。     

热固性丙烯酸酯液晶

介绍了热固性丙烯酸酯液晶单体的合成路线、取向方式和聚合工艺，叙述了数种影响热固性丙烯酸酯液晶单体及其聚合物性能的主要因素，简要介绍了国内外热固性丙烯酸酯液晶研究的最新动向。     

顶空气相色谱-质谱联用法测定胶粘剂中的残余单体

建立了一种测定胶黏剂中6种丙烯酸酯和甲基丙烯酸酯类残余单体的分析方法。样品经100 ℃、30 min顶空加热后,通过DB-WAX色谱柱(30 m×0.25 mm×0.25 μm)分离和质谱选择离子模式检测,内标法定量。结果表明,6种残余单体能达到良好的分离,检出限(信噪比为3)为0.069～0.096 mg/kg,定量限(信噪比为10)为0.23～0.32 mg/kg,平均回收率为96.0%～104.6%,相对标准偏差(RSD)小于7.2%。该方法操作简便、准确、重复性好、灵敏度高,可用于胶黏剂中丙烯酸酯和甲基丙烯酸酯类残余单体的快速测定。     

分子结构对丙烯酸酯类单体接枝LLDPE影响的研究

利用HAAKE密炼机对比研究了甲基丙烯酸缩水甘油酯(GMA)、甲基丙烯酸羟丙酯(HPMA)、甲基丙烯酸羟乙酯(HEMA)、甲基丙烯酸乙酯(EMA)、甲基丙烯酸甲酯(MMA)以及丙烯酸羟乙酯(HEA)等具有不同分子结构的丙烯酸酯类单体对线性低密度聚乙烯(LLDPE)的接枝反应.通过对不同温度下不同反应时间的产物接枝率的测定,发现丙烯酸酯类单体接枝聚烯烃过程中均存在解聚现象.开始发生解聚现象的温度,也即解聚温度(ceiling temperature,Tc),与单体分子结构有关.讨论了位阻效应和特殊基团(如羟基等)相互作用对解聚温度的影响,并通过丙烯酸酯类单体的溶液聚合反应确认了不同丙烯酸酯类单体的解聚温度范围.讨论了添加苯乙烯(St)作为助单体对不同丙烯酸酯类单体接枝率的影响,并结合Q-e法则和竞聚率对其进行了解释.     

含氟/硅丙烯酸酯乳液的合成进展

含氟丙烯酸酯聚合物具有良好的成膜性、光泽性、柔韧性、耐污性及耐腐蚀性,广泛应用于防腐耐候涂料。但其对基体的附着性差,对颜料、填料的润湿性差,不耐低温,加之含氟丙烯酸酯单体价格昂贵,大量使用受到限制。含氟/硅丙烯酸酯共聚物不仅兼备了含氟聚合物的诸多优良性能,而且能有效地提高与基体的附着力并降低聚合物成本。本文综述了氟/硅改性丙烯酸酯乳液常用单体;核壳型乳胶粒的结构及影响因素;氟/硅丙烯酸酯共聚物合成路线。     

甲基丙烯酸羟乙酯改性水性聚氨酯乳液的制备及性能

采用种子溶胀乳液聚合法,以水性聚氨酯为种子,甲基丙烯酸羟乙酯、甲基丙烯酸甲酯和丙烯酸丁酯为单体制备水性聚氨酯丙烯酸酯复合乳液,考察了甲基丙烯酸羟乙酯含量对复合乳液的T型剥离、胶膜的硬度、耐水性和力学性能的影响。结果表明,随着甲基丙烯酸羟乙酯含量的增加,复合乳液的T型剥离强度、胶膜的硬度和拉伸强度增大,胶膜的耐水性先增大后减小,断裂伸长率有所降低,适宜的甲基丙烯酸羟乙酯用量为3%。     

硅溶胶改性水性超薄型钢结构防火涂料的研究

以过硫酸铵为引发剂,OP-10为乳化剂,在聚乙烯醇保护下,用甲基丙烯酸甲酯、丙烯酸丁酯进行共聚,合成乳液型丙烯酸酯树脂,并用红外光谱表征.用磷酸、五氧化二磷、季戊四醇反应生成的酯型中间体与三聚氰胺混合,制得膨胀型阻燃剂,用红外光谱表征并对其进行热重分析.用自制膨胀型阻燃剂与乳液型丙烯酸树脂及少量硅溶胶按一定比例混合调匀,制备超薄型钢结构防火涂料,根据国家标准对涂料性能进行检测,其基本性能达到防火涂料要求.     

阻燃剂对5Ah锂离子软包电池倍率性能和安全性能的影响研究

在电解液中加入不同含量(5 %,10 %,20 %)的阻燃剂,研究了其对LiNi _0.4Co_0.2Mn_0.4 O₂三元材料作为正极材料组装的5 Ah锂离子软包电池的倍率性能、过充性能和短路性能的影响. 实验结果表明,电解液中5 %体积含量的阻燃剂使软包电池在1C和2C放电时,具有最好的倍率性能;当阻燃剂的体积含量提升到20 %,在过充时,电池表面温度升高的最少;在短路实验时,电池不起火、不爆炸.     

阻燃剂及材料的阻燃处理

阻燃剂是能够保护材料不着火或使火焰难以蔓延的化学物质。介绍了常见阻燃剂的种类、阻燃机理、材料的阻燃处理及新型阻燃剂的发展,以增强人们对阻燃技术领域的认识和了解。     

绿色环保型氢氧化镁阻燃剂

介绍了阻燃剂的种类和发展趋势,并重点介绍了氢氧化镁阻燃剂的阻燃机理、特点、应用和发展。指出氢氧化镁阻燃剂是一种新型的、对环境友好的无机阻燃剂。     

Polyamides incorporating phosphine oxide groups. III. Polymerisation of bis[4-(2-aminoethyl)aminophenyl]-phenylphosphine oxide with dicarboxylic acids

The new polymerisation monomer bis[4-(2-aminoethyl)aminophenyl]-phenylphosphine oxide (p-BAPPO) was prepared in good yield by the nucleophilic substitution reaction between bis(4-fluorophenyl)phenylphosphine oxide and a large excess of 1,2-diaminoethane. Five novel polyamides, incorporating phosphine oxide groups within the polymer backbone were synthesised by the condensation reaction of p-BAPPO with a series of aromatic and aliphatic dicarboxylic acids. The thermal properties of these polymers were investigated by differential scanning calorimetry and thermogravimetric analysis. Glass transition temperatures in the 180–215°C range were recorded. Although we observed their thermooxidative stabilities (5% weight loss > 345°C) to be lower by 40–70°C than those previously found for wholly aromatic polyamides with phosphine oxide groups within the parent chain, char yields upon prolonged heating at 650°C were still excellent (26–38%). Also, good solubility in aprotic polar solvents was observed for all polyamides synthesised. The new polyamides clearly represent significant progress in the quest for processible fire retardant materials. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2865–2870, 1997     

Effect of acrylic polymer and nanocomposite with nano-SiO2 on thermal degradation and fire resistance of APP-DPER-MEL coating

Acrylic nanocomposite and flame retardant coatings with different acrylic polymers were prepared. The effect of molecular structure and molecular weight of acrylic resins and nanocomposite with nano-SiO₂ on the interaction and char formation of ammonium polyphosphate-dipentaerythritol-melamine (APP-DPER-MEL) coating was investigated using differential thermal analysis (DTA), thermogravimetry (TG), Limiting Oxygen Index (LOI), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and fire protection test. The interaction of APP, DPER, MEL and 3F-1 acrylic resin led to the formation of intumescent coherent char at 300-450 °C. Owing to low molecular weight and lack of benzene rings, F-963 acrylic resin decomposed at lower temperature than APP, and hence their endothermic interaction was destroyed. The well-distributed nano-SiO₂ particles in acrylic nanocomposite could modify char formation and anti-oxidation of char structure at high temperature. It is noted that the fire protection properties of nanocoating with acrylic nanocomposite were better than those of flame retardant coatings with conventional acrylic resins.     

Synthesis of a novel hybrid synergistic flame retardant and its application in PP/IFR

A novel inorganic-organic hybrid synergistic flame retardant was prepared by sol-gel reaction and characterized by NMR and FT-IR. It showed that the fire resistance of polypropylene/intumescent flame retardant (PP/IFR) composites could be improved with the combination of hybrid synergistic flame retardant. The char morphology and structure of PP composites were characterized by SEM and Raman spectra. The influence of the hybrid flame retardant on the thermal degradation process of PP composites was analyzed by FT-IR and the rheological behavior of the PP composites was also evaluated. The thermal stability of PP composites was characterized by TGA, weight loss difference and integral procedural decomposition temperature (IPDT). It indicated that the hybrid synergistic flame retardant had good synergistic effect with IFR.     

无卤阻燃丙烯腈共聚物的制备及性能

以K₂S₂O₈-NaHSO₃ 氧化还原体系为引发剂, 采用水相沉淀自由基聚合法合成丙烯腈(AN)-醋酸乙烯酯(VAc)无规共聚物[P(AN-co-VAc)], 然后在KOH水溶液中进行P(AN-co-VAc)中VAc单元的选择性水解, 再与磷酸和尿素进行磷酰化反应, 制备无卤阻燃丙烯腈共聚物. 用核磁共振氢谱(¹H NMR)、傅里叶变换红外光谱(FTIR)、差示扫描量热(DSC)和热重分析(TGA)对聚合物结构及热性能进行表征, 用凝胶渗透色谱(GPC)测定了P(AN-co-VAc)的分子量及其分布, 并利用FTIR和扫描电子显微镜(SEM)对无卤阻燃丙烯腈共聚物的炭残渣进行分析. 结果表明, VAc与AN发生共聚反应, 制得了P(AN-co-VAc), 随着KOH水溶液pH值的增大, P(AN-co-VAc)中VAc单元迅速水解; DSC分析结果表明, 随着共聚物中VAc单元含量的增大, 共聚物的环化放热分解峰值温度(T_p)增大, 当VAc单元的质量分数为25%时, T_p最大值高达328 ℃, 而阻燃丙烯腈共聚物的T_p高达340 ℃; TGA分析结果表明, 阻燃共聚物在800 ℃时的炭残渣量高达55%以上, 远高于P(AN-co-VAc)的41%, 具有良好的成炭性; 炭残渣的FTIR及SEM结果表明, 阻燃丙烯腈共聚物的阻燃属于凝聚相阻燃.     

Structural and thermal interpretation of the synergy and interactions between the fire retardants magnesium hydroxide and zinc borate

The mechanism of cooperative action of commercial fire retardants is interpreted as resulting from specific chemical reaction and phase changes. This investigation focuses on the thermally initiated interactions between two forms of commercially available fire retardant compounds. The fire performance of a polyolefin with a metal hydroxide fire retardant, magnesium hydroxide, can significantly reduce the heat release rate through absorption of heat during conversion to its metal oxide. Formation of water, followed by vaporisation, decreases heat and dilutes volatiles from polymer degradation. The second form of fire retardant compounds are zinc borates (2ZnO·3B₂O₃·3H₂O and 4ZnO·B₂O₃·H₂O), that undergo dehydration with increasing temperature. Differential thermal analysis and wide-angle X-ray spectroscopy indicated that various structural changes occurred during heating. Endothermic transitions were observed for all components, while zinc borate (2ZnO·3B₂O₃·3H₂O) showed an exothermic crystallisation transition at relatively high temperature. The exotherm was modified by the development of a new crystalline phase, magnesium orthoborate (3MgO·B₂O₃) that formed on reaction with magnesium oxide (MgO) at temperatures greater than 500 °C. Formation of crystalline zinc oxide (ZnO) was also detected. From zinc borate (4ZnO·B₂O₃·H₂O), ZnO was primarily formed. No new crystalline phases were observed in the presence of MgO over the temperature range investigated.     

Effect of ethylene-acrylic acid copolymer on flame retardancy and properties of LLDPE/EAA/MH composites

Halogen-free flame retardant linear low density polyethylene (LLDPE)/ethylene-acrylic acid copolymer (EAA) blends were prepared in a melt process using magnesium hydroxide (MH) as flame retardant. The effect of EAA on flame retardancy and properties of LLDPE/EAA/MH composites was studied. The flammability of composites was investigated using Limiting Oxygen Index (LOI) and Cone calorimeter test. The results showed that the introduction of EAA into composites apparently increased LOI from 28% to 39%, meanwhile, reduced heat release rate (HRR) and smoke production rate (SPR) according to Cone calorimeter results, which was mainly due to the uniform dispersion of MH as a result of hydrogen bonding and acid-base reaction between MH and EAA. This improved interfacial adhesion was confirmed by Scanning Electronic Microscopy (SEM). Thermogravimetric analysis (TGA) showed that EAA could enhance the thermal oxidative stability of composites. It was attributed to the formation of a stable barrier to prevent the heat and mass transfer in fire, which was confirmed by the observation of fire performance with Cone calorimeter. The crystallization and rheological behaviour of composites were studied using Differential scanning calorimeter (DSC) and oscillatory rheological measurements. Mechanical test results indicated that the addition of EAA could increase the elongation at break and impact strength of composites.