Synthesis and properties of polyurethane elastomers based on renewable castor oil polyols

In this contribution, castor oil polyols with functionality of f = 2.7 and f = 2 are used as soft segments (SS) for synthesizing polyurethane elastomers (PUEs) without addition of petroleum-based polyol. The effect of molar ratio of castor oil polyols on structure and properties of PUEs has been investigated by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, X-ray diffraction, tensile, swelling, and water absorption tests. The results reveal that hydrogen bonding mainly exists in hard segments (HSs) and weakens with decreasing the molar percentage of castor oil polyol (f = 2.7) in SS. T _g of SS decreases while T _g of HS remains constant as molar percentage of castor oil polyol (f = 2.7) decreased. The initial degradation temperatures (T_5%) are above 300 °C and independent of the molar ratio of castor oil polyols. However, the temperature at 50% weight loss (T_50%) decreases significantly as molar percentage of castor oil polyol (f = 2.7) decreased. Moreover, PUEs exhibit very low water absorption rate, <1%, after immersing in water for 140 h at room temperature. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47309.     

Measurements of Two-Dimensional Distribution of Refrigerant Concentration in EHL Film Using Micro FT-IR and Effect of Variation of Concentration on Oil Film Thickness

The dissolution of refrigerant into a lubricant causes a decrease in viscosity of the oil and it gives a large effect on the lubrication of sliding parts in a refrigerant compressor. This paper describes an application of micro FT-IR to measure the two-dimensional concentration distribution of refrigerant held in solution in the EHL film surrounded by the refrigerant gas and discusses the refrigerant concentration variation in the vicinity of the Hertzian contact area. In order to measure the concentration distribution, an apparatus which can observe the EHL film in a point contact in the refrigerant atmosphere was developed. The refrigerant concentration was measured using micro FT-IR through a CaF₂ window from outside of the apparatus with polyol ester as a base oil in an atmosphere pressurized with HFC-134a refrigerant gas. The results indicate that the concentration of HFC-134a refrigerant reduces in the inlet boost region of EHL contact and the Hertzian contact area but in the side region of Hertzian contact area it is greater than that in the bulk fluid. In addition, the effect of the variation on the oil film thickness is discussed.     

含磷本质阻燃硬质聚氨酯泡沫塑料的制备及性能

以苯基膦酰二氯(BPOD)和乙二醇(EG)为原料合成含磷长链二元醇(P-polyol),用于制备含磷本质阻燃硬质聚氨酯泡沫塑料(RPUF),研究了P-polyol对聚氨酯泡沫塑料性能的影响。结果表明,使用P-polyol制备的聚氨酯泡沫,含磷量为1.82%时,极限氧指数达到24.7%;微型燃烧量热仪(MCC)测试显示,燃烧过程的热释放容量、总热释放量和热释放峰值均有所下降。热重分析(TGA)结果显示,在氮气中热分解后700℃的残炭量为22.6%,在空气中热氧化分解后700℃的残炭量为17.0%,较纯RPUF均提高了1倍以上。阻燃后聚氨酯泡沫的压缩强度比空白组提高了130%,并保持了原有的冲击强度,这一优点是众多添加型阻燃剂难以实现的。     

多功能阻燃剂聚醚多元醇膦酸酯/亚磷酸酯的合成

以丙三醇作为起始剂,三溴苯酚缩水甘油醚、环氧氯丙烷及环氧丙烷为共聚单体,以三氟化硼/四氢呋喃为催化剂合成的阻燃聚醚多元醇作原料,与亚磷酸三甲酯进行酯交换反应和Arbuzov重排反应,合成了新型聚醚多元醇膦酸酯/亚磷酸酯(PEPP)。通过元素分析和IR及1HNMR等分析方法对其化学结构进行了表征。考察了反应物料比对多元醇(HIROL-II)的性能和PEPP应用性能的影响。试验结果表明,适宜的环氧丙烷/环氧氯丙烷/三溴苯酚缩水甘油醚物质的量比是6∶1 1∶1,用23%PEPP制备的聚氨酯泡沫氧指数为31。PEPP是一种热稳定性高、阻燃效果好,同时兼有增塑剂和抗氧剂功能的新型橡塑助剂。     

新型阻燃聚醚多元醇的合成研究

以 3 (2 ,4 ,6 三溴苯氧基 )环氧丙烷为阻燃单体 ,N ,N 二 (2 羟基乙基 ) 2 ,4 ,6 三溴苯胺为起始剂 ,合成了具有阻燃特性的聚醚多元醇。着重考察了反应物料比、投料方式、反应时间等因素对阻燃聚醚多元醇物理性质及收率的影响。应用试验结果表明 :适合制造软泡材料的阻燃聚醚多元醇原料配方是 :起始剂 /环氧丙烷/ 3 (2 ,4 ,6 三溴苯氧基 )环氧丙烷物质的量比为 0 18/ 3/ 1。当阻燃聚醚多元醇质量分数为 19%的国产 2 5 # 软质聚氨酯泡沫 ,氧指数达 2 7 1,其它物理特性也满足了GB/T 2 4 0 6 - 1993的要求。     

自动电位滴定在大分子量聚酯多元醇羟值测定中的应用

在目前通用的乙酸酐-吡啶法测羟值的基础上,针对低羟值聚酯多元醇建立了准确度更高的分析方法,并采用自动电位滴定法测定聚酯多元醇的羟值。测试结果表明,该法提高了测试的准确度,并可解决深色和浑浊样品无法手动滴定的问题。     

用聚合物多元醇制备自结皮聚氨酯泡沫

利用聚合物多元醇(POP)和聚醚多元醇同时作为共聚单体制备了聚氨酯自结皮泡沫(ISF),并对其反应机理、配方、工艺以及制品性能进行了研究,制备的聚氨酯自结皮泡沫综合性能优良,可广泛用于汽车方向盘、扶手、头枕、摩托车鞍座、靠背、门把、阻流板以及保险杠等。     

聚醚型高硬度聚氨酯弹性体的研制

采用聚氧化丙烯多元醇、二醇扩链剂和多异氰酸酯为原料，用一步法工艺制得一系列高硬度聚氨酯弹性体。讨论了多元醇组分平均每个羟基所对应的链段的相对分子质量(MOH)、平均官能度以及异氰酸酯种类对高硬度聚氨酯弹性体性能的影响。结果表明，采用液化MDI或粗MDI与聚氧化丙烯醚配合使用可以制得邵D硬度大于65的聚醚型高硬度聚氨酯弹性体。     

不饱和硬脂酸季戊四醇酯的合成及对PVDC热降解影响

以硬脂酸、季戊四醇为原料采用直接酯化法合成了不饱和硬脂酸季戊四醇酯(UPS),利用傅立叶变换红外光谱仪对其结构进行了表征,并将其作为辅助稳定剂与硬脂酸钙/锌复配加入到聚偏二氯乙烯(PVDC)树脂中,采用刚果红法、热烘箱老化法、热失重分析法考察了PVDC样片的静态热稳定变化,采用转矩流变仪测试了PVDC的动态热稳定性与流变性能.结果表明:UPS可以与Ca-Zn稳定剂产生协同效应,起到抑制锌烧的作用,提升了PVDC的初始分解温度和热稳定性.     

水性聚氨酯涂料的合成

总结并讨论了水性聚氨酯涂料（PUR）的合成技术，包括组分和双组分系统，对单组分系统，可通过非离子和阴离子亲水改性合成高分子量的线型聚氨酯分散体，对双组分系统，异氰酸酯组分为水可分散的聚异氰酸酯，100％固体；羟基组分可为聚氨酯多元醇，也可以是含羟基聚丙烯酸酯类。