聚氨酯弹性体的动态力学性能的影响因素

综述了聚氨酯弹性体动态力学性能的多种影响因素,讨论了软段类型(聚酯和聚醚)、软段相对分子质量、硬段类型(二异氰酸酯和扩链剂)、硬软段质量分数对PU弹性体动态力学性能的影响。在PU弹性体中,聚酯软段比聚醚软段的Tg高,弹性模量依PPG、PEG、PTMG软段顺序增加。     

Influence of the chemical structure of PUR prepolymers on thermal stability

The thermal stability of adhesives for load-bearing construction has been one of their key parameters since engineered wood products were introduced in timber construction. In the case of one-component moisture-curing polyurethane (1C PUR) adhesives, knowledge about relationships between their chemical structure and the resulting bonding properties is limited, especially under high-temperature conditions. In this study the structure-property relationships of 1C PUR prepolymers were analyzed in the temperature range from 20 to 200 °C by means of mechanical and rheological tests. NCO-terminated urethane prepolymers were prepared from systematically varied MDI and polyether mixtures. The structural parameters investigated were the urea and urethane group content, cross-link density, ethylene oxide content and the adjustment of functionality via NCO or polyether component. Bonded wood joints were tested for their tensile shear strength and polymer films were analyzed by means of DMA and DSC. The results revealed a significant influence of hard segment content and cross-link density on the thermal stability of the prepolymers. Not all parameters that affect the film properties significantly influence bonding.     

不同原料对合成PUR弹性体性能的影响

采用相同官能度、不同分子量的聚醚多元醇和甲苯二异氰酸酯(TD I)及扩链剂反应合成了系列聚氨酯(PUR)弹性体,同时对所合成的PUR弹性体进行了表征。结果表明,聚醚多元醇的相对分子质量对PUR弹性体的性能有较大影响,相对分子质量越大,柔性链段含量就越多,弹性体的拉伸强度、断裂强度和硬度就减小,断裂伸长率则相对提高。同时也进一步证明了软硬链段之间的均匀分布和较强的相互作用更有利于弹性体力学性能的提高。     

聚酯-聚醚混合型水性聚氨酯的合成工艺研究

以聚己二酸丁二醇酯二醇（PBAG）和聚乙二醇（PEG）为软链段,以异佛尔酮二异氰酸酯（IPDI）和二羟甲基丙酸（DMPA）为硬链段,采用预聚体法制备了水性聚氨酯（WPU）,研究了R值（NCO／OH摩尔比）、DMPA用量、聚酯与聚醚摩尔比等对乳液的粘度、粒径、稳定性和聚氨酯胶膜力学性能的影响。结果表明,选用尺值为2．0、DMPA质量分数为3．5％、聚酯与聚醚摩尔比为2．5,制备的聚酯-聚醚混合型WPU的粒径可以达到310nm,粘度达到65mPa·s,其离心稳定性和wPU膜力学性能良好。经WPU涂层整理织物的耐静水压达到6．08kPa,透湿量达4550g／（m2×24h）,符合服用性能的要求。     

The physical and mechanical properties of polyurethanes from oleic acid polyols

Three different polyester polyols, with various oleic acid content, were used in the preparation of polyurethane (PUR) coatings. The polyols were designated as Alk28, Alk40, and Alk65, in which 28, 40, and 65 represent the percentage of oleic acid of the polyol formulations. These polyester polyols were reacted with aromatic diisocyanate [toluene diisocyanate (TDI)] to form PUR coatings. The acid value, hydroxyl value, molecular weight, and viscosity of the polyols have been determined. The reaction between the polyols and TDI was studied by Fourier Transform Infrared spectroscopy and X‐ray diffraction (XRD). The effects of varying NCO/OH ratio and oleic acid content of polyols on physical and mechanical properties of PUR films were studied. XRD results indicate that the samples are amorphous. PURs, made with Alk28, have the best mechanical properties followed by Alk40 and Alk65. The mechanical properties of the samples have increased as the NCO/OH ratio was increased from 1.2 to 1.6. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

新型低成本耐老化聚氨酯弹性体的研究

以酯基间有2~6个碳原子的聚酯二元醇（CMA-24、CMA-44、CMA-254、CMA-66）、甲苯二异氰酸酯和扩链剂3,5-二甲硫基甲苯二胺（DMTDA）为原材料,通过预聚体法制备了一种耐水解聚酯型聚氨酯弹性体。探讨了水解稳定剂、防酶剂、紫外线吸收剂和抗氧剂等助剂对聚氨酯弹性体性能的影响,测定了耐水解聚酯型聚氨酯弹性体的耐湿热老化和耐海水性能。结果表明,通过添加适量的水解稳定剂、防霉剂、紫外线吸收剂和抗氧剂可大幅度提高聚酯型聚氨酯弹性体的耐湿热老化和耐紫外线老化性能,特别是耐海水性能较传统的聚酯型聚氨酯弹性体提高了5倍以上。     

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。     

聚酯／聚醚型聚氨酯胶粘剂合成与性能研究

用不同的聚酯和聚醚为原料合成双组分聚氨酯胶粘剂,找到合成该胶粘剂的最佳工艺条件、工艺配方、考察了异氰酸酯及环氧树脂改性剂含量对胶粘剂机械性能的影响。实验结果表明,加入扩链剂可明显提高胶粘剂的机械强度;加入少量环氧树脂可明显提高胶粘剂的拉伸剪切强度,但使剥离强度降低了许多。     

聚丁二烯聚氨酯-脲密封材料的性能研究

以端羟基聚丁二烯 (HTPB)、二异氰酸酯 (TDI或IPDI)为原料制备预聚体 ,利用多元胺或多元醇作固化剂 ,制成聚氨酯及聚氨酯 脲弹性体。测试了这些材料的力学性能、动态力学性能、粘接性能、耐介质、耐水解及透气性能。结果表明 :HTPB型聚氨酯 脲具有优良的力学性能 ,其耐介质及耐水解性明显优于聚醚型或聚酯型聚氨酯 ,具有很好的密封性能 ,可用作水下密封材料。     

H_(12)MDI型水性聚氨酯胶膜力学性能研究

以二环己基甲烷二异氰酸酯(H12MDI)和聚醚或聚酯多元醇合成水性聚氨酯(WPU)乳液,通过对其胶膜力学性能测试及差示扫描量热法(DSC)分析,研究了合成配方及工艺条件对WPU胶膜力学性能的影响。结果表明,采用聚酯多元醇PCDL1000以及纯4,4′体的H12MDI为主要原料,合成乳液过程中提高二羟甲基丙酸(DMPA)用量和后扩链程度,以及采用分步投料均可提高WPU胶膜拉伸强度。     

弹性纤维熔纺聚合物研究的进展

介绍了非聚氨酯类、聚酯型聚氨酯类、聚醚型聚氨酯类聚合物及扩链剂在熔纺弹性纤维上的应用。指出 ,非聚氨酯类聚合物所熔纺的纤维具有较好的耐热性 ,耐氯性及定型性 ,弹性回复率较差 ,低于 95 %。用预聚体作交联剂的聚酯型聚氨酯熔纺纤维的弹性回复率高于前者 ,略低于聚醚型聚氨酯类。用芳香族二醇作扩链剂的聚醚型聚氨酯纤维 ,耐热性较好、弹性回复率较高 ,其性能接近溶液纺丝产品     

Polyester-Polyether Block Copolymers II. Thermal and Mechanical Properties of Poly(hexamethylene terephthalate)/Poly(oxytetramethylene) Block Copolymers

The melting and crystallisation behaviour of crystalline phases in poly (hexamethylene terephthalate)/poly(oxytetramethylene) block copolymers have been investigated in relation to copolymer composition and polyether block molecular weight (m.w.). In contrast to that in corresponding homopolymer blends, the polyester crystallinity in the block polymers is greatly reduced by incorporation of polyether units, though some persists even at low polyester contents. Concomitant changes in the glass transition temperatures show part of the polyester component to form a homogeneous component of the amorphous phase. The mechanical properties change with composition in parallel with the changes in copolymer crystallinity and T_g. Copolymers with 20-60 w % of poly(oxytetramethylene) units of m.w. 2000 are highly extensible elastomers. Those with higher m. w. polyether blocks have higher modulus and strength but suffer a serious loss of properties at 60d?C. The observations are interpreted in terms of a model in which polyester crystallites (and polyether crystallites also, for the higher m. w. polyether blocks) are supported within an amorphous matrix by tie-molecules whose nature changes with the copolymer compositions. The results are compared with those for analogous polyester-polyethers having different structural components.     

共混改性废旧聚氨酯的再生研究

采用聚甲基丙烯酸甲酯(PMMA)与热塑性聚氨酯(PUR-T)共混改性废旧聚氨酯(PUR),探讨了PMMA与PUR-T用量对PUR再生料的力学性能、加工性能的影响,并分析了树脂与CaCO3的界面相容性.结果表明,添加PMMA或PUR-T共混改性废旧PUR均能使材料的力学性能有所改善;但添加PMMA使再生料的加工性能有所下降,而添加PUR-T使再生料的加工性能提高,通过扫描电子显微镜观察发现,其共混体系中树脂与CaCO3的界面接合性要比PMMA共混体系好.     

聚酯/聚醚型聚氨酯互换膜材的制备与应用

为了优化聚氨酯(PUR)包膜尿素控释性能,采用多亚甲基多苯基异氰酸酯分别与聚酯和聚醚多元醇按不同配比混合,依照不同次序先后喷涂在尿素颗粒表面制备聚酯型和聚醚型PUR互换层包膜尿素并利用分光光度法研究其控释性能。通过接触角、热重分析和扫描电子显微镜对膜材的润湿性、热稳定性和形貌进行了表征,并采用傅立叶变换红外光谱分析了尿素释放过程中膜层的结构变化。结果表明,聚酯型PUR的疏水性弱于聚醚型PUR,但热稳定性高于后者;两者的包覆次序影响PUR包膜尿素的控释效果,聚酯型PUR为外层、聚醚型PUR为内层时控释性能优良,当两者包覆比例(质量比)为1.5∶1.5时,释放期最长可达84 d。     

稳定水性聚氨酯分散液的合成研究

以聚酯、聚醚混合低聚物二醇为原料 ,采用二级扩链技术[1] 合成了阴离子分散液 ,并研究了聚酯二醇/聚醚二醇、NCO/OH等因素对其性能的影响 ;当原料为 PBA/PEG=(1～ 4)∶ 1 ,NCO/OH=(1 .5～ 1 .8)∶ 1时能够得到黏度、硬度、柔韧性、吸水率、拉伸强度、断裂伸长率、分散性、机械稳定性等综合性能优良的分散液。     

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。     

Polyether and polyester polyol based glycidyl-terminated polyurethane modified epoxy resins: Mechanical properties and morphology

A glycidyl-terminated polyurethane prepolymer was synthesized and used to enhance the properties of epoxy resins. Some properties of glycidyl-terminated PU/epoxy with polyether based (PPG) and polyester based (PBA) glycidyl-terminated PU were investigated in this research. The polyether based glycidyl-terminated PU(PPG) modified epoxy resin proved to be superior to conventional epoxy resins in improved impact strength and fracture energy, but not tensile strength, tensile modulus, flexural strength and flexural modulus. On the other hand, the polyester based glycidyl-terminated PU(PBA) modified epoxy resin had increased mechanical properties while showing slight variation of impact strength and fracture energy. Different mechanisms for this behaviour are advanced in this paper.     

增容剂对PVDF/PUR-T复合材料的性能影响

采用流延成膜法制备了硅烷偶联剂KH–560和端氨基液体丁腈橡胶(ATBN)协同改性的聚偏氟乙烯(PVDF)/聚醚型热塑性聚氨酯弹性体(PUR–T)复合材料,初步探讨了单一增容剂(KH–560或ATBN)含量、复配增容剂含量与比例及成膜温度等条件对PVDF/PUR–T复合材料力学性能的影响,深入研究了复合材料的结晶性能、热稳定性能和亲/疏水性能。结果表明,与单一增容剂相比,复配增容剂的引入明显提高了复合材料的力学性能,并且当复配增容剂添加量为10%,复配比KH–560/ATBN=3/1,成膜温度为50℃时,其与PVDF/PUR–T基体间的界面粘结性明显得到改善,改性后复合材料断裂伸长率达到273%。PUR–T与复配增容剂的加入抑制了PVDF的结晶,复合材料的结晶度降低,但仍具有良好的热稳定性能,且疏水性得到提高。     

打印涂层用聚氨酯胶粘剂的合成

以混合低聚物二醇、异佛尔酮二异氰酸酯、异佛尔酮二胺等为原料合成了固含最为45%的打印涂层用聚氨酯胶粘剂.讨论了不同种类的多元醇、二异氰酸酯及异氰酸酯与多元醇的物质的量比、不同小分子扩链剂对聚氨酯胶粘剂性能的影响,同时采用FT-IR、托力仪等测试仪器对聚氨酯胶粘剂进行结构表征、力学、硬度和耐水性测试.结果表明:选用聚酯PNA、聚氧化丙烯二醇PPG混合多元醇,n(-NCO):n(-OH)=4,m(1,4-丁二醇):m(新戊二醇)=6:2时,合成的聚氨酯胶粘剂膜硬度可达61,透明度良好,并有良好的抗粘连性和耐水性,满足打印涂层用聚氨酯胶粘剂的要求.     

Incidence of the polyol nature in waterborne polyurethane dispersions on their performance as coatings on stainless steel

Three waterborne polyurethane dispersions derived from polyester, polyether and polycarbonate diols with molecular weight of 1000 Da were synthesized by the acetone method and used as coatings on stainless steel 304 plates. The properties of the dispersions and the polyurethane films were influenced by the polyol nature. The polyurethanes obtained with polyether or polyester showed higher degree of phase separation between the soft and the hard segment. The higher adhesive strength under shear stresses was obtained in the joints produced with the waterborne dispersion obtained with polycarbonate diol. The properties of the polyurethane coating obtained with polycarbonate diol on stainless steel 304 were significantly higher as compared with the others. Improved performance of coatings obtained with polycarbonate diol was ascribed to the higher polarity of the carbonate groups that contributed to additional hydrogen bond formation between soft segments with respect to those obtained with polyether or polyester