硬质聚氨酯泡沫塑料阻燃研究进展

本文阐述了硬质聚氨酯泡沫塑料阻燃研究的必要性和重要性,介绍了硬质聚氨酯泡沫塑料的燃烧过程,概述了阻燃材料的三种作用机理。文中介绍了硬质聚氨酯泡沫塑料的几种常用的添加型阻燃剂,总结了它们各自的阻燃机理、优缺点及研究进展,指出由具有协同作用的阻燃元素构成的复配型阻燃剂是当下研究热点。文中还举例介绍了反应型阻燃剂常用的改性方法以及创新性的思路,最后阐述了硬质聚氨酯泡沫塑料阻燃技术的现状及未来发展趋势。     

聚氨酯/环氧树脂互穿网络硬质泡沫塑料反应过程和微观结构

聚氨酯／环氧树脂互穿网络(PU／EPIPN)硬泡中异氰酸根的消耗速度较纯PU硬泡高，是由于环氧树脂的固化荆同时也是异氰酸根反应的催化荆。而PU／EP IPN硬泡中环氧基的反应速度和反应程度均较纯EP网络低，归因于互穿网络对基团扩散的阻碍。在互穿网络硬泡形成过程中，存在环氧开环中所新产生的羟基与异氰酸根的反应、大分子多元醇中羟基与环氧基的反应以及异氰酸根与环氧基形成嗯唑烷酮的反应三种形成网络间的化学键的途径。同时由于PU／EPIPN硬泡高度的交联，使得IPN硬泡中两个网络具有良好的相容性。动态力学性能表明所有IPN样品都只有一个玻璃化温度。透射电镜表明IPN样品无明显的相界面。     

膨胀阻燃硬质聚氨酯泡沫塑料热降解及燃烧产烟研究

采用热失重、X-射线光电子能谱分析、氧指数及烟密度测试等方法研究了可膨胀石墨(EG)与聚磷酸铵(APP)复配膨胀阻燃硬质聚氨酯泡沫塑料(RPUF)的热降解、燃烧性能及产烟行为.在此基础上利用锥形量热仪考察了EG/APP对磷酸三(β-氯异丙基)酯(TCPP)阻燃RPUF体系燃烧性能的影响.研究表明,EG与APP间的相互作用导致了EG/APP体系高温阶段失重速率下降、残炭量显著上升;EG/APP与RPUF之间的成炭作用以APP的化学成炭为主.与RPUF比较,RPUF/EG/APP的氧指数由19.8%提高至35.4%的同时,烟密度没有显著上升.对比EG、APP及EG/APP阻燃RPUF,体系残炭量越高、炭层耐热氧化能力越强,氧指数就越大;残炭表面越致密,产烟量就越少.添加EG/APP可显著降低含卤体系RPUF/TCPP的热释放、烟释放及CO释放速率,体现了EG与APP复合体系物理与化学膨胀结合的优势.     

聚氨酯／丙烯酸酯类树脂互穿网络的结构形态与力学性能研究

通过示差扫描量热计，扫描电与广角Ｘ－光衍射仪研究了由化二亚胺改性二苯基甲烷二异氰酸酯合成的聚氨酯（ＰＵ）与丙烯酸酯类树脂（ＶＥＲ）形成的同步互穿网络（ＳＩＮ）的结构，形态与力学性能，发现网络间的化学键对其影响极大，网络间没有化学键宫接的ＰＵ＝ＶＥＲＳＩＮｓ是一个热力学不相容体系，存在显示的相分离形态，后者同时与两个网络的形成速率与工程因素有关；对于网络间有化学键连接的ＰＵ／ＶＥＲＳＩＮｓ，两个网络     

聚氨酯/乙烯基酯树脂互穿聚合物网络阻尼性能的研究

采用二步法制备了聚氨酯／乙烯基酯树脂互穿聚合物网络,动态力学分析法研究了ＩＰＮ的阻尼性能。结果表明,聚氨酯／乙烯基酯树脂互穿聚合物网络出现宽温度阻尼范围。当聚氨酯／乙烯基酯树脂＝４０／６０时,材料的宽温度范围的阻尼性能最好。在体系中引入柔性链可改善低温阻尼性能,而引入刚性链则降低阻尼值、提高阻尼温度、阻尼温度范围变窄。在体系中引入大侧基能显著提高聚氨酯／乙烯基酯树脂互穿聚合物网络的阻尼性能,提高交     

玻纤增强硬质聚氨酯材料的合成及其力学性能

以聚醚多元醇,玻璃纤维(G)及多次甲基多苯基多异氰酸酯为原料,采用一步法制备了玻纤增强硬质聚氨酯复合材料(RPU-G).对RPU-G的力学性能进行了研究,结果表明,随着G含量(m)的增加,其拉伸强度呈先升后降的变化趋势;当m为10%[长径比(n)为20～40]时,RPU-G20～4010 的力学性能达到最佳.由于G的n不同,其增强效果差异显著,以RPU-G20～4010的拉伸强度最大(0.80 MPa),与RPU相比提高了95%.压缩强度因G的n不同出现不同的趋势,仍以n为20～40的G增强效果最为明显,RPU-G20～405的压缩强度增加了10%.     

聚氨酯一聚丙烯酸酯共聚乳液的合成研究

以甲基丙烯酸β－羟乙酯封端的聚氨酯大分子单体与丙烯酸酯类单体进行乳液共聚，合成了以聚丙烯酸酯（PA）为主链、聚氨酯（PU）为侧链的接枝共聚物（PA－g－PU）乳液，用IR光谱和^1H NMR光谱对该聚氨酯大分子单体及PA－g－PU接枝共聚物进行了表征，并对影响聚氨酯－聚丙烯酸酯共聚合的因素进行了探讨。结果表明：聚氨酯大分子单体的加入对乳液聚合的速率造成较大的影响。该体系的表观活化自由能为99.39KJ/mol,Rp∝[I]^0.87,Rp∝[S]^0.12。     

聚氨酯与接枝乙烯基酯树脂互穿网络研究: 自由基共聚 单体的影响

通过分子设计技术合成了两种侧链种类和长度可能控制的接枝乙烯基酯树脂(VER),并用它们与聚氨酯(PU)形成了同步互穿网络(SIN)。通过DSC,SEM,TEM,FTIR等考察了接枝VER的共聚单体对VERSIN的形态结构与力学性能的影响。研究结果表明,用甲基丙烯酸甲酯(MMA)为共聚单体的接枝VER网络中的MMA链段与PU网络中的硬段有较好的相容性,导致这类PU/接枝VERSIN中两个网络间的相容性和互穿程度好于由苯乙烯为共聚单体时合成4SIN。因此,在这两类共聚单体合成的SIN中,由MMA形成的接枝VER网络增强PU网络的效果更为显著。     

8—羟基喹啉—酚酞—改性聚氨酯泡沫塑料分离富集水中微量镉的研究

本文研究了８－羟基喹啉－酚酞负载在开孔聚氨酯泡沫塑料，用于水样中痕量镉的富集和原子吸收法测定，考察了振荡平衡时间（或流速）水相酸度和干扰元素的影响，提出一种新的快速富集－ＡＡＳ方法，水样中痕量镉可定量回收。     

甲苯二异氰酸酯形成的聚氨酯脲与接枝乙烯基酯树脂互穿网络研究

本文首先通过分子设计技术合成了一系列侧链长度可以控制的接枝乙烯基酯树脂 (接枝VER :BO g VER ,2 0 0 g VER ,390 g VER) ,并用它们与甲苯二异氰酸酯合成的聚氨酯脲 (PUU)形成同步互穿网络(SIN) .通过DSC、SEM等考察了接枝VER的结构对PUU/接枝VERSIN的形态与力学性能的影响 .在PUU/BO g VERSIN中 ,BO g VER网络主要与PUU网络中的硬段相容和互穿 ;对于PUU/ 2 0 0 g VERSIN而言 ,2 0 0 g VER网络与PUU网络中的软段和硬段均有一定的相容性 .由于这两种SIN中两个网络间均有一定的相容性和互穿 ,故这类接枝网络能显著地增强PUU网络 ,使材料的力学性能有较大幅度的提高 .390 g VER网络本身存在的微相分离结构 ,使PUU/ 390 g VERSIN两个网络也存在显著的相分离形态 ,导致390 g VER网络对PUU网络的增强效果并不明显 .     

新型耐腐蚀含氟环氧乙烯基酯树脂的合成与性能

以含氟环氧树脂（F-EP）、丙烯酸（AA）和甲基丙烯酸（MAA）为单体,用顺丁烯二酸（MA）进行改性,合成了含氟环氧乙烯基酯树脂（F-EVER）。用傅里叶红外光谱、热重分析、力学性能分析等手段对产物进行表征,研究了树脂的耐腐蚀性能。结果表明：当以N,N-二甲基甲酰胺（DMF）为催化剂,羧基与环氧基摩尔比为0.9,MA与...     

Studying the Suitability of Nineteen Lignins as Partial Polyol Replacement in Rigid Polyurethane/Polyisocyanurate Foam

In this study, nineteen unmodified lignins from various sources (hardwood, softwood, wheat straw, and corn stover) and isolation processes (kraft, soda, organosolv, sulfite, and enzymatic hydrolysis) were used to replace 30 wt.% of petroleum-based polyol in rigid polyurethane/polyisocyanurate (PUR/PIR) foam formulations. Lignin samples were characterized by measuring their ash content, hydroxyl content (Phosphorus Nuclear Magnetic Resonance Spectroscopy), impurities (Inductively Coupled Plasma), and pH. After foam formulation, properties of lignin-based foams were evaluated and compared with a control foam (with no lignin) via cell morphology, closed-cell content, compression strength, apparent density, thermal conductivity, and color analysis. Lignin-based foams passed all measured standard specifications required by ASTM International C1029-15 for type 1 rigid insulation foams, except for three foams. These three foams had poor compressive strengths, significantly larger cell sizes, darker color, lower closed-cell contents, and slower foaming times. The foam made with corn stover enzymatic hydrolysis lignin showed no significant difference from the control foam in terms of compressive strength and outperformed all other lignin-based foams due to its higher aliphatic and p-hydroxyphenyl hydroxyl contents. Lignin-based foams that passed all required performance testing were made with lignins having higher pH, potassium, sodium, calcium, magnesium, and aliphatic/p-hydroxyphenyl hydroxyl group contents than those that failed.     

A Bridge-Linked Phosphorus-Containing Flame Retardant for Endowing Vinyl Ester Resin with Low Fire Hazard

The high flammability of vinyl ester resin (VE) significantly limits its widespread application in the fields of electronics and aerospace. A new phosphorus-based flame retardant 6,6’-(1-phenylethane-1,2 diyl) bis (dibenzo[c,e][1,2]oxaphosphinine 6-oxide) (PBDOO), was synthesized using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and acetophenone. The synthesized PBDOO was further incorporated with VE to form the VE/PBDOO composites, which displayed an improved flame retardancy with higher thermal stability. The structure of PBDOO was investigated using Fourier transformed infrared spectrometry (FTIR) and nuclear magnetic resonances (NMR). The thermal stability and flame retardancy of VE/PBDOO composites were investigated by thermogravimetric analysis (TGA), vertical burn test (UL-94), limiting oxygen index (LOI), and cone calorimetry. The impacts of PBDOO weight percentage (wt%) on the flame-retardant properties of the formed VE/PBDOO composites were also examined. When applying 15 wt% PBDOO, the formed VE composites can meet the UL-94 V-0 rating with a high LOI value of 31.5%. The peak heat release rate (PHRR) and the total heat release (THR) of VE loaded 15 wt% of PBDOO decreased by 76.71% and 40.63%, respectively, compared with that of untreated VE. In addition, the flame-retardant mechanism of PBDOO was proposed by analyzing pyrolysis behavior and residual carbon of VE/PBDOO composites. This work is expected to provide an efficient method to enhance the fire safety of VE.     

新型高冲击韧性环氧乙烯基酯树脂的合成和表征

通过引入柔性环氧封端聚醚(ETPE)单体, 报道了一种温和且高效制备新型高冲击韧性的乙烯基酯树脂(EVER-2)的方法。 用傅里叶变换红外光谱(FTIR)、核磁共振氢谱(¹H NMR)和碳谱(¹³C NMR)等技术手段对其结构进行了表征, 并对其拉伸强度、弯曲强度和冲击韧性等力学性能和热变形温度进行了测试。 结果表明, 只需少量的ETPE参与反应(约占树脂总质量的7.9%), EVER-2固化产物就具有很高的冲击韧性。 其SEM的冲击断面形貌表明, 新型高冲击韧性乙烯基酯树脂为均相结构, 其与玻璃纤维有很好的粘结能力。 提出了EVER-2及其与玻璃纤维复合材料 EVERL-2可能的增韧机理。     

磷杂菲改性腰果酚多元醇的合成及阻燃聚氨酯硬泡性能

采用生物质原料腰果酚和9,10-二氢-9-氧杂-10-膦杂菲-10-氧化物(DOPO)为原料, 合成了一种磷杂菲改性腰果酚多元醇(P-Cardanol-Polyol), 并利用核磁共振氢谱和磷谱对其结构进行了表征. 利用P-Cardanol-Polyol对聚氨酯硬泡(RPUF)进行阻燃改性, 得到一系列阻燃聚氨酯硬泡. 考察了P-Cardanol-Polyol的用量对阻燃聚氨酯硬泡的形貌、 密度、 热导率、 压缩性能、 热稳定性以及阻燃性能的影响. 研究结果表明, P-Cardanol-Polyol对聚氨酯硬泡的密度影响可以忽略不计; 随着P-Cardanol-Polyol的加入, 阻燃聚氨酯硬泡的平均孔径逐渐减小, 热导率也逐渐降低. 未改性聚氨酯硬泡的最大热释放速率和总放热量分别为390 kW/m²和31.9 MJ/m², 阻燃聚氨酯硬泡则降低至340 kW/m²和24.6 MJ/m². 此外, 阻燃聚氨酯硬泡的压缩强度比未改性聚氨酯硬泡提升了约13%. 炭层分析结果表明, P-Cardanol-Polyol能够促进聚氨酯硬泡形成连续致密且具有良好抗热氧化性能的炭层, 有利于减少燃烧过程中可燃性气体的逸出, 从而提升阻燃性能.     

乙烯基酯树脂整体柱用于溶菌酶的分离

以甲基丙烯酸间苯二酚二缩甘油酯树脂兼作单体和交联剂,偶氮二异丁腈(AIBN)为引发剂,十六醇为致孔剂,在不锈钢柱管中制成聚合物整体柱,通过电镜分析考察了该聚合物的微观孔结构.以此聚合物整体柱为基质,将该柱修饰为具有二醇基的聚合物整体柱,考察了此修饰柱的通透性,并将其作为高效液相色谱固定相考察了该柱对溶菌酶(Lys)的最大吸附量、α-淀粉酶(α-Amy)和溶菌酶在该柱上的分离,并对蛋清中的溶菌酶进行了分离.结果表明,分离效果良好,为蛋白分离提供了一种简单、快捷、有效的方法.     

Lignin as a Partial Polyol Replacement in Polyurethane Flexible Foam

This study was focused on evaluating the suitability of a wide range of lignins, a natural polymer isolated from different plant sources and chemical extractions, in replacing 20 wt.% of petroleum-based polyol in the formulation of PU flexible foams. The main goal was to investigate the effect of unmodified lignin incorporation on the foam’s structural, mechanical, and thermal properties. The hydroxyl contents of the commercial lignins were measured using phosphorus nuclear magnetic resonance (³¹P NMR) spectroscopy, molar mass distributions with gel permeation chromatography (GPC), and thermal properties with differential scanning calorimetry (DSC) techniques. The results showed that incorporating 20 wt.% lignin increased tensile, compression, tear propagation strengths, thermal stability, and the support factor of the developed PU flexible foams. Additionally, statistical analysis of the results showed that foam properties such as density and compression force deflection were positively correlated with lignin’s total hydroxyl content. Studying correlations between lignin properties and the performance of the developed lignin-based PU foams showed that lignins with low hydroxyl content, high flexibility (low T_g), and high solubility in the co-polyol are better candidates for partially substituting petroleum-based polyols in the formulation of flexible PU foams intended for the automotive applications.     

Chlorine-Functional Silsesquioxanes (POSS-Cl) as Effective Flame Retardants and Reinforcing Additives for Rigid Polyurethane Foams

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.