聚酯多元醇羟值测定方法的比较及优选

本文对测定聚酯多元醇羟值的几种酰化方法进行比较研究,分析了几种方法在测试过程中的适用范围及存在问题。通过比较提出了操作简便,快速适用的乙酸酐-N-甲基咪唑-DMF法,该方法催化酰化反应在45℃水浴中进行,完成一次测定耗时可以由行业标准方法的1～2h缩短至20min,且测试数据与行业标准法测试数据接近。     

聚醚多元醇的制备及其在皮革涂饰剂中的应用

叙述了用于皮革涂饰剂生产上的聚醚多元醇制备及在皮革涂剂生产上的应用。     

无CFC硬泡用低粘度聚醚多元醇

介绍了一种具有自乳化性、高羟值低粘度聚醚多元醇。以该聚醚多元醇为基础,制备了无ＣＦＣ或ＣＦＣ减半ＰＵ硬泡,包括ＨＣＦＣ－１４１ｂ减关体系、正（异）戊烷发泡体系、全水发泡及ＣＦＣ－１１减半体系。实验结果表明,该聚醚与ＨＣＦＣ－１４１ｂ、戊烷及水等相溶性好,组合料贮存稳定,硬泡物性优良,说明该聚醚可广泛应用于各种无ＣＦＣ ＰＵ硬泡体系。     

Natural Palm Olein Polyol as a Replacement for Polyether Polyols in Viscoelastic Polyurethane Foam

The impact of replacing three polyether polyols with different levels of a single palm olein‐based natural oil polyol (NOP) was systematically correlated with the changes in foaming reactivity, cell structure, physico‐mechanical properties, and morphology of viscoelastic (VE) foams. The data show that replacing the polyether polyols with the NOP slightly increased the rate of the foaming reactivity. Increasing the NOP content resulted in increased cell size and cells remained fully open. Increased NOP content contributed to higher load bearing properties of VE foam, which can be attributed to higher functionality of NOP compared to polyether polyols. Addition of the NOP slightly increased the resilience of the foams, however, the hysteresis which is the measure of energy absorption remained mostly unaffected. Age properties, characterized by dry and humid compression sets, were mostly unaffected by the replacement of the polyether polyol with the NOP. The addition of NOP did not impact the morphology of the VE foam polymer matrix, which appears to retain a low degree of hard and soft segment domain separation. Overall, the results demonstrate a feasibility that the NOP can be used to partially replace the polyether polyols in VE polyurethane foams without significant impact on the functional performance.     

Rigid polyurethane foams based on soybean oil

Both HCFC‐ and pentane‐blown rigid polyurethane foams have been prepared from polyols derived from soybean oil. The effect of formulation variables on foam properties was studied by altering the types and amounts of catalyst, surfactant, water, crosslinker, blowing agent, and isocyanate, respectively. While compressive strength of the soy foams is optimal at 2 pph of surfactant B‐8404, it increases with increasing the amount of water, glycerin, and isocyanate. It also increases linearly with foam density. These foams were found to have comparable mechanical and thermoinsulating properties to foams of petrochemical origin. A comparison in the thermal and thermo‐oxidative behaviors of soy‐ and PPO‐based foams revealed that the former is more stable toward both thermal degradation and thermal oxidation. The lack of ether linkages in the soy‐based rather than in PPO‐based polyols is thought to be the origin of improved thermal and thermo‐oxidative stabilities of soy‐based foams. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 467–473, 2000     

Desaminated glycolysis of water‐blown rigid polyurethane foams

Glycolysis reaction kinetics of methylene diphenyl diisocyanate‐based water‐blown polyurethane foams was examined by gel permeation chromatography. Glycolysates were reacted with butyl glycidyl ether to convert toxic aromatic amines to polyols, and their products were identified by ¹H‐NMR spectroscopy. To examine the quality of recycled polyol, polyurethane foams were reprepared using the virgin and recycled polyol mixtures with varying compositions. Cell structures and sizes of reprepared foams were similar to those of original ones when the recycled polyols were mixed up to 30 wt %. Density, thermal conductivity, and flexural strength of the reprepared foams were compared with those of the original ones, and no difference was observed below the recycled polyol concentration of 30 wt %. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2646–2656, 2000     

芳烃聚酯多元醇的合成及应用研究

介绍了以聚对苯对二甲酸乙二醇酯残渣和二乙二醇为主要原料制备低成本芳烃聚酯多元醇的工艺路线，讨论了温度，ＤＥＧ和ＰＥＴ残渣的摩尔比对芳烃聚酯多元醇性能的性能。试验表明，最佳反应温度为１９０℃－２２０℃，最佳摩尔比为１．２２－１．３４。研究了稳定剂对聚酯多元醇组合料贮存稳定性的影响，组合料贮存期在半年以上。聚酯型聚所酯硬泡的氧指数达２７．５％。     

分步加料法合成聚酯多元醇

以二元醇分步加料法合成了聚酯二醇。研究结果表明，该法与一步法相比具有某些优点，例如：实际分子量与理论计算值相近，合成过程中副产物及二元醇损失为较少。研究还表明，保持最后一次加二元醇时反应体系ｎＯＨ／ｎＣＯＯＨ＝２是必要的。     

PIPA多元醇的合成

通过大量实验寻找出简易、有效制备PIPA多元醇的工艺,并通过红外测试证实了产物的合理性。还探讨了温度、固含量、异氰酸酯指数、水的量等因素对反应体系的影响,并指出了合成过程中,以上因素的合理用量。如果在制备PIPA多元醇时加入少许稳定剂,则可以很好地提高PIPA多元醇的稳定性。     

不同结构多元醇与MDI的绝热反应动力学研究

用一系列不同结构的低聚物多元醇与4,4'-二苯基甲烷二异氰酸酯(纯MDI)进行本体聚合,比较了低聚物多元醇的结构单元、相对分子质量以及官能度等因素对绝热反应温度变化曲线的影响,同时用线性优化方法求取了它们的反应动力学参数.结果表明,含有极性较大的结构单元的低聚物多元醇,反应活化能较大;低聚物多元醇的反应速率受温度影响明...