固化温度对苯甲基化木材制备的聚氨酯树脂微相分离的影响

以二价酸酯DBE(己二酸、戊二酸、丁二酸的混合酯)与乙酸丁酯(质量比5：1)的混合溶剂为液化试剂的苯甲基化木材溶液与甲苯二异氰酸酯／三羟甲基丙烷(TDI／TMP)的预聚物为固化剂进行反应制备了聚氨酯树脂。利用FT-IR、DSC、WXRD、DTA及TG等测试手段,研究了固化温度对聚氨酯树脂的微相分离和热性能的影响。结果表明,高温固化样品的微相分离程度较小,树脂的硬段初始分解温度有所降低,但软段的初始分解温度则有所提高。     

阳离子水性聚氨酯的相反转与性能

引言 水性聚氨酯通常是在多元醇和多异氰酸酯加成反应而得的预聚物中引入亲水扩链剂二羟甲基丙酸、甘油单酸酯[1]、酒石酸[2]或二乙烯三胺[3]、二溴丁二酸、N-甲基二乙醇胺[4]等,经中和后,在高速搅拌下将离子化聚氨酯加至水中,或将水加至聚氨酯离聚体有机溶液中,形成聚氨酯水分散液.Dieterich[5]和Lorenz[6,7]及Chan[8]等用黏度法和电导率法研究了阳离子型聚氨酯10%的丁酮溶液在不同温度下加水分散的相转变过程, 认为全过程可分为硬段区表面离子基团吸附水而分离、水进入硬段的无序和有序区、软硬段区重组形成分散微粒的3个阶段,相转变过程与硬段结构、离子基团含量和分散温度相关;寇波[9]、鹿秀山[10]等研究了阴离子型离聚体的50%丁酮溶液的相转变,结果表明,随着软段相对分子质量升高,体系的相转变点后延,聚酯体系的相转变比聚醚体系的相转变发生得早.     

液化木薯淀粉制备聚氨酯木材胶粘剂

利用酸催化液化木薯淀粉制成木薯淀粉液化产物(LCS);然后以多亚甲基二异氰酸酯(p MDI)/环氧树脂(EP)为固化剂X、二月桂酸二丁基锡(DBTDL)为催化剂,LCS与p MDI反应而成的端羟基聚氨酯(HTPU)为主剂,制备快干型木材胶粘剂。研究结果表明:当LCS中w(木薯淀粉)=35.4%(相对于甘油质量而言)、HTPU中w(p MDI)=14.29%(相对于LCS质量而言)、固化剂X中m(pMDI)∶m(EP)=2∶1且w(固化剂X)=52.6%(相对于HTPU质量而言)、w(轻质碳酸钙)=9.5%和w(DBTDL)=0.3%(均相对于胶粘剂质量而言)时,制成的胶粘剂能有效增强胶合板的粘接强度。     

新型聚氨酯固化剂的研究

阐述了颜色低于铁钴比色计1号,游离TDI含量小于0.5%,贮存稳定性达2年以上的新型聚氨酯固化剂的生产工艺;确定了含羟基丙烯酸树脂与该固化剂的质量比为:m(含羟基丙烯酸树脂):m(新型聚氨酯同化剂)=10:4～6;分析了碱性物质是导致聚氨酯固化剂成胶的原因;提出了保证聚氨酯固化剂低色值、低游离TDI含量和高贮存稳定性的方法.     

杉木液化产物用于胶粘剂制备的研究

研究用少量的苯酚液化木材及其产物用于胶粘剂制备的方法,在硫酸催化剂作用下,用苯酚液化杉木木粉,得到木材液化产物.在液化产物中加入适量的甲醛和氢氧化钠溶液制备热固性酚醛树脂.压板测试结果表明,由木材液化产物所得树脂的干状胶合强度令人满意,但经蒸汽循环试验后,湿状胶合强度尚达不到JAS标准的要求,在下阶段工作中,需进一步研究木材液化产物胶粘剂的改性以提高其胶合耐久性.     

高硬度双组分水性聚氨酯的合成

合成了双组分水性聚氨酯木器漆用羟基丙烯酸树脂及可水分散的水性聚氨酯固化剂。优化条件为 :羟基丙烯酸树脂的酸值为 2 2～2 5mgKOH/g,w(—OH) =2 %～ 2 5 % ,硬单体质量分数 35 %～5 0 % ,助溶剂质量分数为 5 %左右的乙二醇单丁醚 ;固化剂乙二醇丁醚改性时 ,(—NCO/—OH)≥ 6 ,聚乙二醇改性时 ,相对分子质量小于 80 0 ,(—NCO/—OH)≥9。两组分配比以 (—NCO/—OH)≥ 1 3为宜     

浆料固含量对有机泡沫浸渍法制备CaO基泡沫陶瓷显微结构的影响

以氢氧化钙和氧化锆为原料,采用有机泡沫浸渍法,经浆料配制、浸渍、挂浆、成型、干燥、1 450℃热处理,在浆料固含量(w)分别为65. 5%、67. 5%、69. 4%和71. 4%的条件下制备了CaO基泡沫陶瓷试样。结果表明,通过制备合适固含量的浆料,可以优化泡沫陶瓷的显微结构:当浆料固含量(w)为69. 4%时,浆料的流变性能得到改善,浆料均匀包覆聚氨酯泡沫,经1 450℃烧后制备的CaO基泡沫陶瓷,骨架厚度为134μm,CaZrO_3均匀分布于CaO的晶界与晶粒中,CaO晶粒发育较好。     

高固含量聚氨酯树脂在鞋革热定型中的应用研究

通过两步法制备出一系列的高固含量聚氨酯树脂，探讨了聚氨酯树脂中-NCO质量分数、固含量、软段类型、扩链剂类型及固化剂含量对聚氨酯鞋革性能的影响。实验数据表明：以IPDI和PTMG-2000反应，扩链剂为1,4-BG，制备出-NCO为10wt%的高固含量聚氨酯树脂预聚体，加入封闭剂己内酰胺进行封闭，添加5wt%的MEK溶剂，获得固含量为95%的高固含量聚氨酯树脂，在高固含量聚氨酯树脂中加入8wt%的HMDA固化剂反应制备的合成革综合性能最佳，制备出的聚氨酯合成革剥离强度达72 N/3 cm、Taber H-22 1 000 g耐磨830转、-20℃6.0万次耐折牢、70℃95RH%恒温恒湿测试10周剥离强度保留为82.5%，革面定型稳定不变形，不起皱，能满足休闲鞋用合成革标准。     

无溶剂浸胶制备玻纤布半固化片工艺研究

以双酚A型环氧树脂和邻甲酚醛环氧树脂复配作为基体树脂,双氰胺为固化剂,咪唑2E4MZ为促进剂,无溶剂法浸胶制备玻纤布半固化片。探讨了基体树脂和促进剂对半固化制备工艺的影响,着重研究了无溶剂法玻纤布浸胶工艺和半固化片制备工艺。研究结果表明:当w(双酚A型环氧)=15%、w(酚醛环氧704)=75%、w(双氰胺)=10%(相对于浸胶总质量而言),w(2E4MZ)=6%(相对于双氰胺质量而言),涂布机温度为110℃下浸胶可达到完全浸润玻纤布;半固化工艺为130℃/9 min时,可得到具有高的分解温度(360℃)、玻璃化转变温度(165℃),耐浸焊性时间长(242 s),击穿电压(46 kV)、介电常数(4.35)、剥离强度(1.45 N/mm)优异的玻纤布半固化片覆铜板。     

封闭型水性多异氰酸酯固化剂的制备及其性能研究

利用甲乙酮肟（MEKO）与IPDI三聚体反应并接枝聚乙二醇单甲醚（MPEG）制备了封闭型水性多异氰酸酯固化剂，采用红外光谱仪、热失质量仪和透射电镜等设备研究了该固化剂的结构、解封温度及胶束形态，同时考察了固化剂对羟基型水性聚氨酯树脂的固化效果及其混合乳液的贮存稳定性。结果表明，该水性固化剂的解封温度在95～249℃之间，最佳使用温度在160℃左右；该固化剂可明显改善羟基型水性聚氨酯膜的耐水、耐溶剂及力学性能，另外固化剂与水性聚氨酯的共混乳液具有良好的贮存稳定性。     

Properties and microstructure of polyurethane resins from liquefied wood

In this article, polyurethane resins were synthesized from liquefied benzylated wood and toluene diisocyanate (TDI)–trihydromethylene propane (TMP) prepolymer (as curing agent). The relations of their segmented structure and properties of were investigated. Results indicated that polyurethane resins made from benzylated wood solution have good mechanical and thermal properties. With the increase of curing agent amount from 23.8 to 53.5%, the degree of phase segregation increased, and under experimental conditions in this article, phase transition was detected with a curing agent amount of 69.9%. After this transition, the mechanical properties of polyurethane resins were improved. Thermal history treatment can also influence microstructure and thermal stabilities of polyurethane samples. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1175–1180, 2005     

Synthesis and properties of polyurethane resins based on liquefied wood

Three polyurethane resins were synthesized from liquefied wood and three diisocyanates, i.e., TDI, IPDI, and HDI. The liquefied wood was obtained by the liquefaction of benzylated wood wastes using Dibasic esters (DBE) as solvent with hydrochloric acid as catalyst for 3 h, at 80°C. The thermal stability and microphase morphology of polyurethane films were investigated by TG, DSC, WAXD, and SEM methods. The experimental results indicated that polyurethane resins from liquefied wood had higher thermal stability than traditional ones, and the special structure and the difference of chemical structure of diisocyanates resulted in the crytallinity and microphase separation of obtained polyurethanes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 351–356, 2004     

木材溶液制备聚氨酯胶粘剂的研究

研究了以苯甲基化木材溶液代替聚醚多元醇制备了聚氨酯胶粘剂，讨论了异氰酸酯用量、聚乙二醇用量、增塑剂用量及固化时间等对胶粘剂性能的影响，并获得了最佳的工艺条件。     

Adhesion properties and phase separation behavior of glycidyl-terminated polyurethanes

2,3-Epoxy-1-propanol has been introduced into isocyanate-terminated polyurethane to form glycidyl-terminated polyurethane resins. A series of glycidyl-terminated polyurethanes based on hydroxyterminated poly(oxypropylene) (poly(oxypropylene) glycol, PPG), toluene diisocyanate (TDI), and 1,4-butanediol (BD) was synthesized with various PPG soft segment lengths (MW 700, 1000 and 2000) and soft segment concentrations (30, 50 and 70 wt.-%). The effects of glycidyl-terminated polyurethane on the adhesion properties and the phase separation were investigated. The adhision properties at liquid nitrogen temperature coincide with the phenomenon observed in the phase separation behavior of polyurethane. Differential scanning calorimetry (DSC) and infrared technique (IR) were used to assess the phase separation content. The enthalpy jump at the glass transition temperature (ΔC_p) and the unique spectroscopic features in the N? H and C?O stretching regions were applied to characterized the phase separation behavior. It was found that the modified resins do not only show superior adhesion at liquid nitrogen temperature but also exhibit some unique properties, e.g., room temperature curing and good storage stability.     

硅胶按键用耐磨聚氨酯树脂的制备与表征

聚氨酯由硬段和软段交替组成,具有良好的物理和机械性能,在硅胶按键保护涂料方面的应用越来越广泛.随着对涂层耐磨性能要求的提高,开发一种针对于硅胶按键表面保护的高耐磨聚氨酯树脂变得十分关键.用聚酯二元醇(相对分子质量580)、乙二醇(EG)、三羟甲基丙烷(TMP)、异佛尔酮二异氰酸酯(IPDI)为原料合成了端羟基聚氨酯预聚物,使用封闭型异氰酸酯作为固化剂交联固化制备聚氨酯薄膜和涂层.研究了聚氨酯薄膜的拉伸性能、热性能以及聚氨酯涂层的耐磨性能,并探讨了EG和TMP用量对聚氨酯薄膜的热性能以及力学性能的影响,重点研究了二者对聚氨酯涂层耐磨性能的影响.测试结果表明:当聚氨酯树脂中EG和TMP的羟基摩尔分数分别为35％ ～ 39％和20％时,聚氨酯涂层的耐磨性能较佳,适用于制备硅胶表面保护涂料.     

高固体分含氟羟基丙烯酸酯树脂的合成及性能研究

分别以甲基丙烯酸十二氟庚酯、甲基丙烯酸六氟丁酯为含氟单体,采用硫代甘油为链转移剂,通过自由基溶液聚合制备了2种含氟羟基丙烯酸酯树脂,考察了硫代甘油用量对树脂相对分子质量、黏度及羟基含量的影响,对树脂结构和热稳定性进行了表征;同时以多异氰酸酯为固化剂制备了聚氨酯涂膜,并对涂膜的表面能、光学透过性、耐化学品性以及常规物理性能进行了测试。结果表明:在硫代甘油用量为4%、固体分含量为60%的条件下,2种树脂的相对分子质量和黏度分别低至1 891、(231±2)mPa·s和2 144、(362±3)mPa·s;聚氨酯涂膜具有一定的疏水性,在可见光区范围内,涂膜光透过率大于98%,并具有良好的耐化学品性及常规物理性能。     

仲氨基笼型倍半硅氧烷改性室温固化环氧树脂的研究

采用直接水解法合成了氨丙基笼型倍半硅氧烷(OapPOSS)。为了改善POSS与环氧树脂的相容性和分散性,在OapPOSS基础上制备了仲氨基笼型倍半硅氧烷(SaPOSS),并将其用于E-51/脂肪胺室温固化环氧树脂改性,研究了SaPOSS对环氧树脂力学性能、玻璃化转变温度、介电性能的影响。结果表明:SaPOSS能显著提高树脂的冲击性能和耐热性,降低介电常数和介电损耗。当SaPOSS加入量为3%时,环氧树脂的冲击强度从原来的20.5kJ/m2,提高到了29.7kJ/m2,玻璃化转变温度从113℃提高到117℃,扫描电镜的观测结果与力学性能的变化趋势相一致。当SaPOSS加入量为5%时,介电损耗从原来的0.035降到了0.024,介电常数也有大幅下降。     

高原铁路捣固车用聚氨酯涂料的研究

以聚酯树脂为基料，HDI三聚体为固化剂，制得了适合高原铁路捣固车使用的特种涂料。研究了不同树脂和固化剂对涂料耐候性、耐磨性和耐温变性的影响。通过FT-IR和TG等检测手段对涂料性能进行了表征。结果表明当选用聚酯树脂C为基料、HDI三聚体DN-90为固化剂时，制得的聚氨酯涂料耐人工加速老化时间可达2000h，涂膜磨耗量可降至0．038g，耐温变20个周期后，检测结果合格。且该涂料固化反应程度完全，热稳定性能好，各组分含量符合设计要求。     

Preparation and characterization of soluble bismaleimide‐triazine resins based on asymmetric bismaleimide

A series of bismaleimide‐triazine resins (EBT) were prepared from 2‐(4′‐maleimido)phenyl‐2‐(4′‐maleimidophenoxyl)phenylbutane (EBA‐BMI) and 2,2‐bis(4‐cyanatophenyl)propane (BADCy). The resins show attractive processability with good solubility in low boiling point solvents and wide processing temperature windows. Introduction of diallylbisphenol A (DBA) can decrease the curing temperature of EBT resins that the curing exothermic peak temperature shifted from 291 to 237 °C as the content of DBA increased from 0 to 20%. The curing condition influenced the thermal properties of the cured EBT resins. The glass transition temperature increased as the curing temperature and curing time increased. The cured EBT resins show high glass transition temperature up to 352 °C, high thermal stability with 5% weight loss temperature over 405 °C, low coefficient of thermal expansion about 45 to 52 ppm/°C, and high storage modulus up to 2.6 GPa at 250 °C. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44519.