TODI类浇注型聚氨酯弹性体的耐热性能研究

用3,3'-二甲基-4,4'-联苯二异氰酸酯(TODI)与聚四氢呋喃(PTMG)、聚己内酯多元醇(PCL)合成了一系列浇注型聚氨酯弹性体,考察了不同聚合物多元醇、扩链剂以及硬段含量对弹性体耐热性能和力学性能的影响.结果表明:PCL体系的耐热性能和力学性能优于PTMG体系,其拉伸强度在120℃下保有率>90%;用3,3'...     

湿热环境用室温固化聚氨酯的研制

采用不同类型的多异氰酸酯、低聚物多元醇、扩链剂以及助剂等原料,制备了系列室温固化聚氨酯材料,讨论了原材料种类对聚氨酯弹性体力学性能和工艺性能的影响。结果表明,选用4,4′-二环己基甲烷二异氰酸酯(H12MDI)为异氰酸酯,聚氧化丙烯醚多元醇为聚合物多元醇,二乙基甲苯二胺(E-100)为扩链剂并配以特殊助剂制备的室温固化聚氨酯材料具有优异的力学性能和工艺性能,湿热条件对该材料最终性能和工艺性能的影响很小,特别适用于无法提供加热条件的湿热环境中。     

高硬度透明聚氨酯材料的研制

选用不同结构的多异氰酸酯、低聚物多元醇、扩链剂等为原料,用半预聚体法和一步法制得一系列高硬度高透明性聚氨酯材料。讨论了合成工艺、多异氰酸酯结构、扩链剂结构和多元醇平均每个羟基所对应的相对分子质量(N值)及其平均官能度对聚氨酯材料性能的影响。结果表明,选择异佛尔酮二异氰酸酯及扩链剂E并控制多元醇平均官能度在2.5～2.7和平均N值在120～150范围内,采用半预聚法制得的高硬度透明聚氨酯材料具有较好的综合力学性能及热稳定性。     

对苯二异氰酸酯型聚氨酯弹性体的合成及性能研究

以对苯二异氰酸酯(PPDI)、低聚物多元醇和小分子二元醇等为原料合成了PPDI浇注型聚氨酯弹性体,考察了不同低聚物多元醇对弹性体的物理机械性能、动态力学性能及热氧老化性能的影响,并与MDI和TDI型聚氨酯弹性体进行了比较。结果表明,PPDI型聚氨酯弹性体较MDI、TDI型弹性体具有更低的内生热、更高的回弹性,可用于轮胎胎面材料的制备。     

弹性条缝筛网用聚氨酯弹性体的研制

采用预聚法常压浇注制备煤矿用聚氨酯筛网，考察了聚醚多元醇、甲苯二异氰酸酯异构体种类、预聚体的NCO质量分数、扩链反应温度、后熟化温度及时间等条件对制筛网用的浇注型聚氨酯弹性体体系操作性能及物理性能的影响。实验表明，采用聚四氢呋喃二醇与聚氧化丙烯二醇的混合二醇(质量比为80：20)，制得的预聚体NCO质量分数控制在4．5％左右；再以MOCA和一种三官能度扩链剂的混合扩链剂进行扩链，制得的浇注型聚氨酯弹性体满足洗煤用筛网的性能要求。     

聚合物多元醇在聚氨酯微孔弹性体中的应用研究

对聚合物多元醇在聚氨酯微孔弹性体中的应用进行了研究。考察了聚合物聚醚多元醇及聚合物聚酯多元醇对聚氨酯微孔弹性体力学性能的影响。实验结果表明,该类聚合物多元醇的引入可使聚氨酯微孔弹性体制品的力学性能得到较大改善,因此该类聚合物多元醇在聚氨酯领域必将具有广阔的应用前景。     

不同多元醇聚氨酯弹性体宏观性能的研究

以聚四氢呋喃多元醇（PTMG）、聚己内酯多元醇（PCL）、4,4′-二苯基甲烷二异氰酸酯、1,4-丁二醇和三羟基聚醚多元醇等为主要原料制备了4种聚氨酯（PU）弹性体。采用电子万能试验机、动态力学热分析仪、差示扫描量热仪以及扩展流变仪等设备分析了不同相对分子质量的PTMG和PCL对PU弹性体的力学性能、热性能以及流变性能的影响。结果表明,PCL类PU弹性体的拉伸强度、硬度、平台区弹性模量、软段玻璃化转变温度以及反应体系的表观黏度都偏高,而PTMG类PU弹性体的滞后损失偏高;同一种类多元醇的PU弹性体的各项性能也因相对分子质量的不同而有差异。     

聚氨酯弛张筛板的试制

以低聚物聚酯多元醇、二苯基甲烷二异氰酸酯(MDI)和1,4-丁二醇(BDO)为原料合成了MDI型聚氨酯弹性体。采用常压浇注成型一定结构的聚氨酯片材,再经机械冲孔而成聚氨酯弛张筛板。讨论了几种成型方法的优缺点以及不同品种聚氨酯弹性体的特点。结果表明,采用MDI型聚氨酯弹性体常压浇注成型片材、经机械冲孔方式加工而成的聚氨酯弛张筛板具有加工工艺简单、曲挠性好、耐磨性能突出、使用寿命长的特点。     

不同异氰酸酯型聚氨酯弹性体的制备与力学性能研究

采用不同结构的异氰酸酯和多元醇制备了一系列聚氨酯弹性体,主要考察了异氰酸酯种类对聚氨酯弹性体力学性能的影响.研究表明,由1,5-萘二异氰酸酯制得的弹性体拉伸强度和撕裂强度较高,分别为38.75MPa和109.77 kN/m,而由对苯二异氰酸酯制得的弹性体具有最大的扯断伸长率(557.84％).此外还研究了多元醇种类和扩链系数α对弹性体力学性能的影响,研究表明,选用聚ε-己内酯二醇制得的弹性体具有较好的性能,且拉伸强度和撕裂强度均随扩链系数的增大先增大后减小,而扯断伸长率一直增大.     

难燃聚氨酯软质泡沫的制备及性能研究

用新型难燃接枝聚合物聚醚多元醇和聚醚多元醇3050的混合物与甲苯二异氰酸酯(TDI)自由发泡反应，制备了阻燃型聚氨酯软质泡沫。讨论了难燃接枝聚合物聚醚多元醇的用量对聚氨酯软质泡沫密度、氧指数和力学性能的影响。结果表明，随着难燃聚醚用量的增加，聚氨酯软质泡沫的阻燃性能提高，力学性能也有显著提高，泡沫体的密度降低。     

Soft polyurethane elastomers with adhesion properties based on palm olein and palm oil fatty acid methyl ester polyols

Soft polyurethane (PU) elastomers with >70% bio-based content and with properties characteristic of pressure sensitive adhesives were prepared from an equimolar ratio of a polyol derived from palm oil fatty acid methyl ester (PolyFAME-EG polyol) and palm olein polyols (Pioneer E-135 and Pioneer M-60) cured with 2,4′- and 4,4′- diphenylmethane diisocyanate isomeric mixture at isocyanate to hydroxyl equivalent weight ratio (Isocyanate Index) of 1.02 and 0.73. FTIR analyses of the resulting elastomers indicate high levels of free non-hydrogen bonded urethanes, indicating phase mixing of hard and soft segments, which explains the transparent nature of the elastomers. The physical properties of the elastomers were correlated with the cross-link density of the palm olein polyols and Isocyanate Index. Elastomers produced at an Isocyanate Index of 1.02 ranges in hardness from 21 to 67 Shore A which correlated with the average polyol functionality. However, at an Isocyanate Index of 0.72 the resulting elastomers were very soft with hardness ranging from 1 to 4 Shore A and with T-peel adhesion to polypropylene in the range from 2.27 to 1.98 N/25 mm. Based on these results, a polyurethane matrix with a high renewable content of palm oil polyols can be used as a platform for the development of transparent elastomers that can be used as soft energy-absorbing materials with potential use in pressure sensitive adhesives.     

The relative physical and thermal properties of polyurethane elastomers: Effect of chain extenders of bisphenols,diisocyanate, and polyol structures

Polyurethane elastomers based on polyols such as polycaprolactone diol of molar mass 2000 and polytetramethylene glycol of molar mass 2000; diisocyanantes such as diphenyl methane 4,4′ diisocyanate and dicyclohexyl methane 4,4′ diisocyanate; and chain extenders such as bisphenol-A, bisphenol-S,bisphenol-AF, and their brominated derivatives were synthesized. The effects of polyol, diisocyanate, and chain extender on the physical and thermal properties were also studied. The polyurethane elastomers were investigated by X-ray diffraction (XRD), differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. Their limiting oxygen indexes (LOIs), solubilities, tensile strengths, hardnesses, and elongations were also determined. XRD analyses revealed that all of the polyurethanes were semicrystalline. However, the addition of bromine atoms in the polyurethanes markedly decreased their degrees of crystallinity. The brominated polyurethane elastomers have good flame retardancy, as indicated by large LOIs. All of the unbrominated polyurethanes showed good mechanical properties and high thermal stabilities. Polyurethanes based on bisphenol-S had lower solvent resistance caused by the dipolar nature of sulfonyl groups in the polymer chains. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1251–1265, 1997     

HTBN/PTMG双软段聚氨酯弹性体的制备及力学性能研究

以甲苯二异氰酸酯(TDI)、端羟基聚丁二烯-丙烯腈共聚物(HTBN)、聚四氢呋喃醚二醇(PTMG)为主要原料,3,5-二甲硫基甲苯二胺(DMTDA)为扩连剂,采用浇铸法制备了聚氨酯弹性体。研究了聚氨酯预聚体中NCO含量、HTBN/PTMG质量比、PTMG相对分子质量和改变扩链剂用量以及热处理时间对聚氨酯弹性体力学性能的影响。结果表明,低相对分子质量PTMG和高热处理温度有利于提高聚氨酯弹性体的力学性能,当聚氨酯预聚体中HTBN/PTMG的质量比为50∶50、NCO质量分数为5.98%、NCO/NH2摩尔比为1.20、115℃下热处理2 h时,聚氨酯弹性体的力学性能最佳。     

Novel hybrid polyurethane/POSS materials via bulk polymerization

Novel polyurethane (PU)/polyhedral oligomeric silsesquioxane (POSS) hybrid elastomers were synthesised via reaction carried out in bulk. The isocyanate octasubstituted POSS (NCOPOSS) was used as the crosslinking agent for the polyurethane systems, which were similar to those commercially available for the production of urethane elastic materials (in contrast to model systems previously reported in literature). The structure and amorphous morphology of the resulting elastomers were confirmed by FTIR ATR spectroscopy and WAXS measurements, respectively. The elastomers were characterized by their mechanical (tensile, hardness) and thermal (T_g, thermal stability) properties. It was found that the incorporation of small amount (1.2–2.5 wt.%) of the NCOPOSS into the formulation resulted in an improvement or deterioration in mechanical properties of the polymer, depending on the diisocyanate used. Further increase in the NCOPOSS concentration resulted only in a loss of mechanical properties. A possible explanation is an over-crosslinking or wastage of POSS-deriving NCO groups (which did not react earlier with bulky polyols) in the reaction with the chain extender leading to cycle formation. Incorporation of the NCOPOSS into the PU elastomer reduced somewhat thermal stability of the latter probably due to the poor thermal stability of the NCOPOSS itself.     

IPDI基浇注型聚氨酯弹性体性能的研究

采用不同品种的多元醇与异佛尔酮二异氰酸酯（IPDI）反应合成了浇注型聚氨酯弹性体,研究了不同多元醇结构对IPDI型聚氨酯弹性体性能的影响;用红外光谱表征了聚氨酯弹性体的结构,并对其进行了力学性能、动态性能和耐溶剂性能测试。结果表明,聚酯多元醇（Pol-2456）的聚氨酯弹性体力学性能最好;聚醚和聚酯型聚氨酯弹性体在较高温度下tan8值仍然保持在0．4左右,可以作为阻尼材料;端羟基聚丁二烯的聚氨酯弹性体的动态性能最好,峰值为0．715（-60．4℃）,-10℃以下,tanδ值基本保持在0．2左右,且具有好的耐溶剂性。     

扩链剂对基于聚酯/MDI聚氨酯弹性体力学性能的影响

用聚酯多元醇(PBA、PEA、PEPA、PCL)、4,4'-二苯基甲烷二异氰酸酯(MDI)和混合扩链剂等原料合成了浇注型聚氨酯弹性体(PUE)。考察了聚酯多元醇种类、预聚体-NCO质量分数、扩链剂和扩链系数(R)等对PUE力学性能的影响,并比较了MDI/混醇体系与2,4-甲苯二异氰酸酯(TDI)/MOCA体系的性能。结果表明,PUE的硬度、模量和撕裂强度随预聚体-NCO含量增加而增加,随交联密度提高,撕裂强度和扯断伸长率下降,R>1.05时,PUE的力学性能急剧变化,MDI/混醇体系比TDI/MOCA体系的冲击弹性好。     

聚醚-酯嵌段共聚物改性微孔聚氨酯弹性体性能的研究

采用双金属氰化物络合催化剂（DMC），以脂肪族己二酸系聚酯多元醇为起始剂，与环氧丙烷（PO）、环氧乙烷（EO）进行烷氧基化反应，制得聚醚酯多元醇用于微孔聚氨酯弹性体（MPUE）的合成，可得到综合性能优良的MPUE材料。在相同硬段含量下，聚醚酯型MPUE的力学性能接近聚酯型MPUE，优于聚醚型MPUE，并且其耐水解性能得到较大的提高，接近聚醚型MPUE。     

聚醚型吸水膨胀聚氨酯弹性体的合成

采用亲水性聚醚多元醇(PPE)与甲苯二异氰酸酯(TDI)反应的预聚体,与混合扩链剂制备了吸水膨胀聚氨酯弹性体。实验结果表明:当聚乙二醇醚(PEG)与聚丙二醇醚(PPG)的物质的量比为6∶4,PEG相对分子质量为2 000,预聚体中异氰酸酯基(—NCO)的质量分数为5.2%;采用混合扩链剂,且1、4-丁二醇与丙三醇的物质的量比为2∶1,增塑剂邻苯二甲酸二辛酯(DOP)的质量分数控制在8%时,制备的聚氨酯弹性体吸水膨胀率高,综合性能良好。     

遇水膨胀聚氨酯防水弹性体的研制

通过筛选实验确定了合成遇水膨胀聚氨酯防水弹性体用的亲水性多元醇的种类、比例以及相关多元醇的相对分子质量.又通过对比实验选定了填料、偶联剂的种类和比例.研制出的防水弹性体综合性能优于国内外同行的市售产品.     

催化体系对聚氨酯泡孔结构及其力学性能的影响

在A1/A33催化体系下,采用新型聚合物聚醚多元醇36/28和普通聚醚多元醇330N与TM300体系反应,制备了一种高回弹聚氨酯泡沫.考察了催化体系对聚氨酯泡沫泡孔结构以及性能的影响,探讨了孔径大小与泡沫力学性能的关系.结果表明,制品的力学性能与聚氨酯泡沫的孔径大小并不是简单的线性关系,还受泡沫开闭孔率的影响,当催化体...