IPN结构聚氨酯改性环氧树脂的性能研究

采用同步互穿聚合物网络技术制备了聚氨酯改性TDE-85/Me THPA环氧树脂体系,比较了环氧树脂TDE-85/MeTHPA固化体系改性前后力学性能和热稳定性的差异。研究结果表明,加入适量的由不同分子量聚醚二元醇合成的聚氨酯预聚体,对TDE-85/MeTHPA固化体系的力学性能、热稳定性均有所增加;当聚醚二元醇分子量为1000,且合成的聚氨酯预聚体加入量为15%时,同未改性的固化体系相比,该改性体系的拉伸强度和冲击强度分别上升48.0%和115%,分别达到69.39 MPa和23.56 kJ/m2,同时,该改性材料的热稳定性也有较明显的提高,其失重1%的温度T1%为300℃,比未改性的固化体系失重1%的温度高了30℃。     

聚氨酯改性环氧树脂胶黏剂的研究与应用进展

简要介绍了环氧树脂胶黏剂的特性,指出聚氨酯改性环氧树脂的主要目的是提高其韧性。分别论述了几种常用的聚氨酯增韧改性环氧树脂胶黏剂的方法,包括端胺基／端羟基／端异氰酸酯基／端环氧基聚氨酯预聚体增韧改性环氧树脂,聚氨酯环氧树脂接枝共聚改性环氧树脂以及聚氨酯互穿聚合物网络增韧环氧树脂,其中详细介绍了聚氨酯互穿聚合物网络增韧环氧树脂技术。同时,对国内聚氨酯改性环氧树脂胶黏剂的主要应用进行了介绍,并指出了我国目前聚氨酯改性环氧树脂胶黏剂的不足和发展方向。     

1993年中国聚氨酯研究与开发应用文摘(三)

聚氨酯水分散体系改性丙烯酸胶粘剂的性能／经菊琴（宁波市化工研究设计院）／聚氨酯工业，1993，（4）：35～36聚氨酯水分散体系加入到丙烯酸树脂胶粘剂中，明显提高胶粘剂的粘结性能。聚氨酯的种类、添加量、湿度、热和光将影响改性后丙烯酸乳液的粘结能力。聚丁二烯型聚氨酯／环氧树脂互穿聚合物网络的研究／贾德民（华南理工大学高分子系）／合成橡胶工业，1993，16（3）：142～145用同步法合成了聚丁二烯型聚氨酯／环氧树脂互穿聚合物网络，借助傅里叶红外光谱、动态力学温度谱、透射电镜和力学性能测试等手段，研究其合成、结构、形态…     

聚氨酯对环氧树脂增韧性能研究

利用甲苯二异氰酸酯(TDI)和聚丙二醇(PPG)合成不同结构的端—NCO聚氨酯(PU)预聚体,然后由聚氨酯预聚体与环氧树脂进行接枝反应,制备聚氨酯改性环氧树脂。研究了聚氨酯预聚体结构和用量对改性环氧树脂力学性能的影响规律。结果表明,当聚醚多元醇选用PPG1000,且TDI∶PPG=2∶1时,制得的聚氨酯预聚体对环氧树脂的增韧效果最好,当ω(PU预聚体)=10%时,改性环氧树脂的应变和拉伸强度分别达到84. 7%和27. 1 MPa,是改性前的30. 47倍和3. 04倍。通过扫描电镜对聚氨酯的增韧机理进行了研究,发现改性前环氧树脂为脆性断裂,聚氨酯改性后的环氧树脂断裂时银纹明显增多,为韧性断裂。     

PU/EP共混物中的化学反应及粘接性能的研究

合成聚氨酯（PU）预聚体同环氧树脂（EP）共混,加入扩链剂、交联剂,制得PU／EP复合材料,用红外光谱分析研究了共混体系中的化学反应,考察了两聚合物组成对聚合物网络间互穿程度的影响,研究了共混物的粘接性能。     

聚氨酯对环氧树脂增韧性能研究

利用甲苯二异氰酸酯(TDI)和聚丙二醇(PPG)合成不同结构的端—NCO聚氨酯(PU)预聚体,然后由聚氨酯预聚体与环氧树脂进行接枝反应,制备聚氨酯改性环氧树脂。研究了聚氨酯预聚体结构和用量对改性环氧树脂力学性能的影响规律。结果表明,当聚醚多元醇选用PPG1000,且TDI∶PPG=2∶1时,制得的聚氨酯预聚体对环氧树脂的增韧效果最好,当ω(PU预聚体)=10%时,改性环氧树脂的应变和拉伸强度分别达到84. 7%和27. 1 MPa,是改性前的30. 47倍和3. 04倍。通过扫描电镜对聚氨酯的增韧机理进行了研究,发现改性前环氧树脂为脆性断裂,聚氨酯改性后的环氧树脂断裂时银纹明显增多,为韧性断裂。     

聚氨酯改性环氧树脂的制备及红外光谱分析

制备了聚氨酯改性环氧树脂体系,并通过红外光谱分析,研究了异氰酸酯端基的聚氨酯预聚体、扩链剂、环氧树脂及其固化剂之间相互反应的规律。结果表明,聚氨酯、环氧树脂二者之间形成IPN结构过程中,环氧树脂与其固化剂之间发生固化反应;扩链剂1,4-丁二醇对PU预聚体进行扩链;同时TDE-85同PU预聚体之间还发生两相间的化学反应,这可有效地提高2种聚合物之间的相容性和稳定性,从而可以提高环氧树脂性能,达到改性目的。     

新型环氧封端聚氨酯/环氧树脂胶粘剂的研制

以多元醇(PPG-2000或PTMG-2000)、甲苯二异氰酸酯(TDI)为主要原料,合成了PU(聚氨酯)预聚体;然后加入E-44型EP(环氧树脂)和缩水甘油醚(Glycidyl)对PU预聚体进行封端,制成E/G-PU(端环氧基PU);再加入TDE-85型EP和活性稀释剂,制备出环保无溶剂型E/G-PU/TDE-85/活性稀释剂胶粘剂;最后采用间苯二甲胺(m-XDA)固化剂和2,4,6-三(二甲胺基甲基)苯酚(DMP-30).促进剂对该EP胶粘剂进行固化,明显提升了体系的固化速率。结果表明:当w(活性稀释剂D-085)=5%时,E/G-PU(PTMG-2000)/TDE-85/D-085胶粘剂的剪切强度(24.63 MPa)相对最大。     

聚碳酸酯型聚氨酯—环氧树脂IPN的性能及结构形态

由甲苯二异氰酸酯和聚六亚甲基碳酸酯二醇制备聚氨酯预聚体，再由该预聚体、双酚A环氧树脂等用同步法合成了聚碳酸酯型聚氨酯-环氧树脂互穿网络聚合物（PCPU－EPIPN）。红外光谱分析表明PCPU和EP两组分间存在一定的化学结合。差示扫描量热分析及热重分析研究表明：IPN在高温区存在单一玻璃化转变峰，当PCPU与EP的质量比mU／mE＝25／75时，IPN的Tg最高且热稳定性最好。透射电镜和扫描隧道显微镜研究表明，PCPU与EP的配比对IPN的形态结构有显著的影响。应力-应变测试发现：当mU／mE＝25／75时IPN体系力学性能最佳。     

聚氨酯改性环氧树脂阴极电泳涂料的制备与性能研究

利用聚醚二元醇、二环己基甲烷 -4,4'-二异氰酸酯（ HMDI）合成— NCO封端的聚氨酯预聚体,再与环氧树脂（E-44）反应生成聚氨酯改性环氧树脂,聚醚二元醇、 HMDI与环氧树脂 E-44的物质的量比为 1∶2∶2。以聚氨酯改性环氧树脂为主体,用一乙醇胺（ MEA）和二乙醇胺（ DEA）对树脂进行环氧开环,封闭型异氰酸酯为固化剂,用乳酸进行酸化中和,加入去离子水乳化得到阴极电泳涂料。结果表明： n（MEA）∶n（DEA）∶n（聚氨酯改性环氧树脂） =4∶4∶3,固化剂用量为 21%,中和度 65%,并加入去离子水可调节成固体分为 12%的稳定阴极电泳涂料,涂料乳白并伴有蓝相。最后在工件上进行电泳涂装,得到表面光滑平整、硬度 3H、耐冲击性 50 cm、耐盐雾 500 h、柔韧性 1 mm、附着力 1级 的阴极电泳漆膜。     

Synthesis and characterization of cryogenic adhesives based on epoxy-modified polyurethane resin systems

Polyurethane adhesives containing the polyether backbone exhibit a good joint strength in cryogenic environments. In practice, many of the commercially available polyurethane adhesive systems contain free or chemically blocked isocyanates which have some limitations. This study presents the synthesis and characterization of a modified polyurethane type adhesive. Glycidol was used to convert the isocyanate-terminated polyurethane prepolymer to glycidylterminated polyurethane prepolymer. A series of glycidyl-terminated polyurethanes, based on polyoxypropylene glycol (PPG) soft segments having different molecular weights, were synthesized and their adhesive properties on aluminium were evaluated. The effect of the soft segment length on adhesion was examined. The adhesive properties at room temperature and cryogenic temperature are in line with the phenomenon observed in dynamical mechanical analysis (DMA) and in the phase separation behavior of the polyurethanes. Differential scaning calorimetry (DSC) was used to assess the phase separation content. An improvement in the adhesive strengths at room temperature is achieved by adding epoxy resins to the glycidyl-terminated polyurethane resins.     

聚氨酯改性环氧树脂胶粘剂的制备及性能研究

由端-NCO基聚氨酯(PU)预聚物与环氧树脂反应,制备了PU接枝改性环氧树脂。着重探讨了PU预聚物的含量、活性稀释剂的含量和异氰酸酯结构等因素,对改性环氧树脂的粘度和粘接性能的影响。实验结果表明,该改性环氧树脂的粘度随着PU预聚物含量的增加而逐渐增大,随着活性稀释剂含量的增加而逐渐降低,而且在相同的条件下,用不同的二异氰酸酯改性环氧树脂的粘度大小次序为:IPDI型>MDI型>TDI型;该改性环氧树脂在PU预聚物含量为20%时,对铝片/铝片的剪切强度最大(7.82 MPa);在PU预聚物含量为10%时,对铁片/铁片的剪切强度最大(11.70 MPa),而且TDI型和IPDI型改性环氧树脂的粘接性能明显好于MDI型改性环氧树脂。     

Polyether and polyester polyol based glycidyl-terminated polyurethane modified epoxy resins: Mechanical properties and morphology

A glycidyl-terminated polyurethane prepolymer was synthesized and used to enhance the properties of epoxy resins. Some properties of glycidyl-terminated PU/epoxy with polyether based (PPG) and polyester based (PBA) glycidyl-terminated PU were investigated in this research. The polyether based glycidyl-terminated PU(PPG) modified epoxy resin proved to be superior to conventional epoxy resins in improved impact strength and fracture energy, but not tensile strength, tensile modulus, flexural strength and flexural modulus. On the other hand, the polyester based glycidyl-terminated PU(PBA) modified epoxy resin had increased mechanical properties while showing slight variation of impact strength and fracture energy. Different mechanisms for this behaviour are advanced in this paper.     

Glycidyl-terminated polyurethane modified epoxy resins: Mechanical properties,adhesion properties,and morphology

Glycidol was used to convert the isocyanate-terminated polyurethane prepolymer to glycidyl-terminated polyurethane prepolymer. The modified polyurethane not only offers some distinct advantages over the commercial polyurethane prepolymer, but also enhances the properties of the epoxy resins. The glycidyl-terminated polyurethane modified epoxy resin proved to be superior to conventional epoxy resins in improving impact strength, fracture energy, and adhesion properties. The compatibility of the compounds in this glycidyl-terminated PU/epoxy system was investigated using different preparation procedures. It was found that the synthesized glycidyl-terminated polyurethane prereacted with curing agents, exhibited a lesser degree of phase separation, and can influence the mechanical properties of polymer blends. The results coincide with the phenomena observed in dynamic mechanical analysis and scanning election microscopy. © 1994 John Wiley & Sons, Inc.     

Synthesis and studies of the physical properties of polyaniline and polyurethane‐modified epoxy composites

Two series of toughened, semiconductive polyaniline (PANI)/polyurethane (PU)‐epoxy (PANI/PU‐EPOXY) nano‐composites were prepared using a conductive polymer, PANI, and PU prepolymer‐modified‐diglycidyl ether of bisphenol A (DGEBA) epoxy. First, the PU prepolymer‐modified epoxy oligomer was synthesized by a stoichiometric reaction between the terminal isocyanate groups of the PU prepolymer and the pendent hydroxyl groups of the epoxide. PU prepolymers were made either of polyester (polybutylene adipate, PBA) or polyether (polypropylene glycol, PPG) segments. The composites were characterized by thermal, morphological, mechanical, and electrical studies. Impact strength was enhanced 100% in PU (PPG 2000)‐modified composites; whereas, only ca. 30–50% increases in impact strength were observed for the other modified composites. In addition, the thermal stability of this composite proved superior to that of neat epoxy resin, regardless of a PU content at 27.5 wt%. Scanning electron microscopy (SEM) morphology study showed that the spherical PU (PPG 2000) particles (ca. 0.2–0.5 μm) dispersed within the matrix accounts for these extraordinary properties. The conductivity of the composite increased to ca. 10^?9–10^?3 S cm^?1 upon addition of PANI when tested in the frequency range 1 kHz–13 MHz. This study demonstrated a useful way to simultaneously improve the toughness and conductivity of the epoxy composite, thus rendering it suitable for electromagnetic interference and various charge dissipation applications. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers     

聚氨酯/聚甲基丙烯酸酯交联聚合物合成与力学性能的研究

采用相对分子质量不同的聚氧化丙烯二醇(PPG)与甲苯二异氰酸酯合成聚氨酯预聚物,将该预聚物用甲基丙烯酸-2-羟乙酯(HEMA)封端后与甲基丙烯酸甲酯(MMA)、甲基丙烯酸丁酯(BMA)进行自由基聚合得到一系列交联聚合物。利用红外光谱(FT-IR)、力学性能测试及动态力学热分析(DMTA)等手段对交联聚合物进行了表征。聚氨酯/聚甲基丙烯酸甲酯(PU/PMMA)交联聚合物具有较高的阻尼值和较宽的阻尼温域,当两组分的质量比为5∶5时,阻尼性能最佳。PU/PMMA交联聚合物的拉伸强度随聚甲基丙烯酸甲酯含量的增加而增加,断裂伸长率随其含量的增加而减小;聚氨酯/聚甲基丙烯酸丁酯(PU/PBMA)交联聚合物的拉伸强度随聚甲基丙烯酸丁酯含量的增加而减小,断裂伸长率随其含量的增加而增大。     

接枝型PUA乳液合成及聚合动力学研究

甲基丙烯酸羟丙酯与水性聚氨酯预聚体反应,得到双烯封端的水性聚氨酯乳液。在乳化剂、引发剂存在下,将丙烯酸酯单体与水性聚氨酯乳液充分混合,并引发聚合,制备了接枝型PUA乳液。TEM观察了PUA乳液的形貌,PUA乳液的粒径在60～120 nm之间;FTIR和NMR表征了合成的PUA结构,显示丙烯酸酯的加入改变了PU本身的氢键相互作用;转化率测试表明,甲基丙烯酸羟丙酯与PU预聚体的反应具有二级动力学特征,而乳化剂的用量影响丙烯酸酯单体与双烯封端聚氨酯乳液的反应速率,反应速率与乳化剂用量符合Rp∝[SDS]0.28。     

硬段含量对聚氨酯和聚氨酯脲氢键化程度的影响

以PPG600,PPG2000,甲苯二异氰酸酯(TDI)和1,4-丁二醇(1,4-BD)为原料合成了聚氨酯(PU),通过改变PPG600,PPG2000配比调节产品硬段含量;以PPG2000,TDI和异佛尔酮二胺(IPDA)为原料合成了聚氨酯脲(PUU),通过调节TDI与IPDA在体系中的比例调节产品硬段含量。利用FT-IR,DSC,旋转黏度计研究了硬段含量对聚醚型PU和PUU的微观结构及黏度的影响。结果表明,随硬段含量提高,PU和PUU的氢键化程度均提高,PU较多地形成不完善的氢键,而PUU倾向于形成完善有序的氢键结构。此外随硬段含量增大,PU和PUU的黏度增大,PU软段的玻璃化转变温度升高。     

无溶剂型单组分聚氨酯胶粘剂的研制

以聚醚二元醇(PPG)、改性MDI(4,4′-二苯基甲烷二异氰酸酯)、PAPI(多亚甲基多苯基多异氰酸酯)、1,4-BDO(1,4-丁二醇)和环保型PU潜固化剂等为主要原料,采用预聚体法制得无溶剂型单组分聚氨酯(PU)胶粘剂。研究结果表明:该胶粘剂的玻璃化转变温度(Tg)为-26.9℃;当R=n(-NCO)/n(-OH)=6.5~9.0、w(-NCO)=3.5%、w(环保型PU潜固化剂)=3%和聚醚二元醇是相对分子质量为1 000的PPG210时,PU胶粘剂的黏度适中、固化速率较快和可操作性良好,并且其强度和韧性俱佳。     

聚醚型聚氨酯增强增韧环氧树脂的研究

用聚丙二醇(PPG400,PPG1000)与异佛尔酮二异氰酸酯(IPDI)反应制备了聚氨酯(PU)预聚体,然后通过与环氧树脂(EP)的加成反应和环氧树脂的固化反应将聚氨酯引入环氧固化物网络,并研究了两种聚醚型聚氨酯对环氧树脂的改性效果。结果发现,聚氨酯的引入不但起到了增韧的作用,而且使体系的强度有了很大的提高。随聚氨酯用量增大,PU/EP材料拉伸强度、弯曲强度、冲击强度均先增大后减小,过多的聚氨酯用量导致其不能接人环氧固化物网络;分子链较短的PPG400型聚氨酯的改性效果优于PPG1000,PU与EP的质量之比的最佳值为15%～20%;1,4-丁二醇/三羟甲基丙烷的引入能够使体系中聚氨酯分子链增长并交联成网状,但并不能进一步提高PU/EP材料的强度和韧性。