聚醚型聚氨酯预聚体合成工艺研究

以聚醚多元醇和异氰酸酯为原料合成聚氨酯预聚体。通过测定—NCO的含量,研究了预聚反应时间和反应温度对预聚反应的影响;研究了R值[n(—NCO)/n(—OH)],反应时间和温度对预聚物黏度的影响,并探讨了预聚反应过程中含水量、预聚体贮存时间对弹性体性能的影响。     

影响聚醚型聚氨酯预聚体合成的因素

以聚乙二醇（PEG）和二异氰酸酯为原料，通过测定-NCO的含量，确定了预聚反应的时间和温度，合成了聚醚型聚氨酯预聚体；对影响预聚体合成的因素：异氰酸酯的种类、n（-NCO）：n（-OH）、二异氰酸酯的自聚、水分的含量以及预聚体的贮存稳定性等进行了研究。     

端异氰酸酯基聚氨酯预聚体的合成与表征

以异佛尔酮二异氰酸酯(IPDI)和聚乙二醇2000(PEG2000)为单体,在二月桂酸二丁基锡(DBTDL)的催化作用下,通过逐步聚合反应合成了NCO封端的聚氨酯预聚体(PPU).通过单因素实验分析法优化出了PPU合成条件:反应温度70℃,w(DBTDL)=0.75%(以IPDI和PEG2000的总质量计),反应时间为1.5 h.利用FT-IR、1H-NMR等方法对单体和PPU的分子结构进行了表征,通过综合热分析测试了PPU的热分解温度T_g为268.2℃.     

预聚体法合成聚氨酯弹性体常见问题分析

对预聚体法合成浇注型聚氨酯弹性体中所出现的气泡多、粘度大、物料变黄等不良现象进行了详细的分析,从它的合成和固化成型过程中查找原因,从而提出解决方法。     

光敏预聚体研究进展

介绍了近年来紫外光固化体系中光敏预聚体的研究进展,以及UV固化涂料的发展动态。     

聚氨酯型光敏树脂结构与性能关系的研究

本文对聚氨酯型光敏树脂结构与性能的关系进行了系统研究，得出了光敏树脂性能与预聚体结构、活性稀释剂结构及用量等关系的规律性结果．     

半预聚体法合成聚醚型聚氨酯弹性体

采用半预聚法合成了聚醚型聚氨酯弹性体;分别对预聚反应的时间、温度进行了考查。确定了合适的反应条件;并对影响弹性体性能的几种因素：水分的含量、软硬段比例、NCO／OH、聚醚的分子质量以及后熟化时间等进行了研究。     

硅烷封端聚氨酯预聚体的合成研究

以聚醚二元醇、二异氰酸酯为主要原料合成了硅烷封端聚氨酯预聚体,使用合成得到的预聚体制备了硅烷封端聚氨酯密封胶并对其性能进行了考察。研究了二异氰酸酯类型,NCO/OH比例,反应温度,扩链剂类型及封端剂类型对硅烷封端聚氨酯(SPU)的影响。结果表明:使用两种混合二异氰酸酯,NCO∶OH=1.3～1.5,二甘醇作为扩链剂,γ-巯丙基三甲基硅烷(KH590)作为封端剂,反应温度85℃制备得到较理想的预聚体,可使硅烷封端聚氨酯密封胶拉伸强度达到1.78MPa,断裂伸长率达到490%。     

聚氨酯预聚体可聚合乳化剂的合成条件研究

将聚醚作为亲油链 ,一端接甲基丙烯酸羟乙酯作为可聚合部分 ,另一端接二羟甲基丙烯酸作亲水基。通过对反应产物的化学分析 ,研究了不同反应温度和反应时间对产物的影响。结果显示 :在较低温度下 ,通过较长的反应时间可以使反应更好地向设计方向进行。     

多种聚氨酯预聚体的合成与应用

介绍了聚氨酯预聚体合成的基本方法,对不同聚氨酯预聚体的合成原料选择、工艺要点、性能及其主要应用领域进行了概述,其中重点列举了其在泡沫及其它方面应用的配方实例。     

聚氨酯甲基丙烯酸酯预聚物合成及反应动力学研究

以甲苯二异氰酸酯（TDI）、PEG1000和甲基丙烯酸-B-羟乙酯（HEMA）为原料,通过分步法合成聚氨酯甲基丙烯酸酯（PUMA）预聚物并对合成工艺及动力学参数进行了研究,确认TDI与PEG、TDI聚氨酯中间体与HEMA这2步反应均为二级反应．反应活化能分别为34．533kJ／mol、87471kJ／mol;这2步反应的最佳反应温度为65℃、70℃,其相应的反应速率常数分别为2．578×10^-3L／（mol·s）、2．1889×10^-2L／（mol·s）。     

紫外光固化脂肪族聚氨酯丙烯酸酯的合成研究

以异佛尔酮二异氰酸酯(IPDI),季戊四醇(PETL)和丙烯酸羟乙酯(HEA)合成了可紫外光固化的四官能团脂肪族聚氨酯丙烯酸酯低聚物。研究了催化剂用量、反应物配比、合成反应温度和反应时间等对反应的影响。确定了最佳合成工艺条件:二月桂酸二丁基锡为催化剂;第1步反应用量为IPDI和PETL总质量的0.05%~0.08%;对羟基苯甲醚为阻聚剂,用量为总投料质量的1%;反应物配比n(PETL)∶n(IPDI)∶n(HEA)=1∶4∶4.12;第1步反应温度控制在55~75℃,反应时间2 h,第2步反应温度65~70℃,反应时间2~2.5 h。     

水性聚氨酯胶粘剂的合成

以环氧树脂、甲苯二异氰酸酯(TDI)、二羟甲基丙酸(DMPA)等为原料合成了水性聚氨酯乳液胶粘剂,用红外光谱对产物结构进行了表征．     

PTMG型聚氨酯预聚体的研制

以聚四亚甲基醚二醇（PTMG）和甲苯二异氰酸酯（TDI）为原料，研究了TDI/PTMG的摩尔比和制备工艺条件，制备出了聚氨酯预聚体。结果表明，当TDI/PTMG的摩尔比为1.80-1.85，且在将PTMG分批加入TDI中的制备工艺条件下可制得相对分子质量分布窄，游离TDI质量分数低，黏度小，稳定性及可操作性能好的聚氨酯预聚体。     

湿固型聚氨酯胶粘剂预聚体的研制

以聚四氢呋喃二醇(PTMG)和二苯基甲烷4,4′-二异氰酸酯(MD I)为主要原料合成湿固型预聚体,研究了湿固型预聚体的制备条件。结果表明,预聚反应的最佳温度为80℃左右,最佳反应时间为2 h,预聚体中-NCO质量分数为3%时,预聚体的稳定性、可操作性能最佳。     

The effect of prepolymer crystallinity on solid-state polymerization of poly(bisphenol A carbonate)

The effect of prepolymer crystallinity on the solid-state polymerization (SSP) of poly(bisphenol A carbonate) was examined using nitrogen as a sweep fluid. A low-molecular-weight prepolymer was synthesized by melt transesterification and prepolymers with different crystallinities (11.7%, 23.3%, 33.7%) were prepared with supercritical carbon dioxide treatment. SSP of the three prepolymers was then carried out at reaction temperatures in the range of 150-190 °C, with a prepolymer particle size of 75 μm and a N₂ flow rate of 1600 ml/min. The glass-transition temperature (T_g), absolute weight-average molecular weight (M_n), and percent crystallinity were measured at various times during each SSP. At each reaction temperature, SSP of the lower crystallinity prepolymer (11.7%) always resulted in higher-molecular-weight polymers, compared with the polymers synthesized using the higher crystallinity prepolymer (23.3% and 33.7%). The crystallinity of the polymers synthesized from the high crystallinity prepolymer was significantly higher than for those synthesized from the low crystallinity prepolymer. Higher crystallinity of the prepolymer and the synthesized polymers may lower the reaction rate by reducing chain-end mobility or/and by inhibiting byproduct diffusion.     

蓖麻油TDI聚氨酯预聚体的制备

利用双键含量、异氰酸酯根(-NCO)含量和游离甲苯二异氰酸酯(TDI)含量的测定,研究了反应条件对蓖麻油聚氨酯预聚体(CO-PU)合成的影响。结果表明,随着反应温度的升高,CO-PU中剩余-NCO的含量逐渐减少,游离TDI含量逐渐降低;增加nNCO/nOH,CO-PU中剩余-NCO和游离TDI含量增大;延长反应时间,-NCO含量减小;加入二丁基二月桂酸锡(DBTDL)后,酯化反应速率加快,体系中-NCO含量明显降低。在-NCO与羟基的反应过程中双键比较稳定,CO-PU中的双键含量基本不变。     

Micropatterning of photosensitive glass-ceramic-polymer composite by sand blasting

Abstract

A photosensitive, sandblasted composite was used to achieve a high aspect ratio of barrier ribs. The authors investigated the erosion of the photosensitive composite prepared with two different pastes: normal and photosensitive. The barrier ribs underwent micropatterning with calcium carbonate powder as the sand blasting erodent material. The patterned green barrier ribs were fired in an air atmosphere and the thermal, physical and mechanical properties of the resulting composites were determined by thermal gravimetric analysis, atomic force microscopy, nanoindentation, and peel testing. The photosensitive composite had better adhesion with a dry film resist and showed lower porosity, surface roughness, stiffness and elastic modulus than a normal composite, which was attributed to the remaining polymer. In the process, the developed photosensitive composite and the dry film resist film were able to withstand the impact of the separated particles or clusters. These results support the use of sand blasting to fabricate the micropatterning of barrier ribs with two layers of photosensitive composite.     

Synthesis and characterization of novel negative-working aqueous base developable photosensitive polyimide precursors

Through molecular designing, three poly(amic esters) (PAEs) have been synthesized from pyromellitic dianhydride (PMDA), 2,2′-bis-(3-amino-4-hydroxyphenyl) hexafluoropropane (BisAPAF), 4,4′-diaminodiphenyl ether (4,4′-ODA) and 2-hydroxyethyl methacrylate (HEMA). Due to the introduction of photosensitive acrylate groups and aqueous base soluble phenolic hydroxyl groups in the backbone, these poly(amic esters) can be used as the precursors of negative-working, aqueous base developable photosensitive polyimides (PSPIs). These poly(amic esters) were prepared by direct polymerization by using phenyl phosphonic dichloride (PPD) as an activator. The inherent viscosities of these polymers were 0.20 (dL/g). Their structures were characterized by Fourier transform infrared spectroscopy (FTIR) and ¹H NMR. In order to improve the photolithographic performance of these PSPIs, different photosensitizers, photoinitiators and a crosslinker have been added in the PSPI formulations. Among them, the Michler's ketone (MK)/tribromomethyl phenyl sulfone (TBPS) system gave the best results. Using a 2.38 wt% aqueous TMAH solution as a developer, patterns with a resolution of 10 μm were obtained from these PSPI formulations. In addition, the effects of the molecular structure of the precursors and the concentration of developer on the photosensitivity of the PSPI formulations were also discussed.