助交联剂在聚醚混炼型聚氨酯中的应用研究

研究了过氧化物类助交联剂HVA-2、TMPTMA、SR517、SR522D和R153D对聚醚混炼型聚氨酯(MPU)硫化特性、交联密度、力学性能、耐热空气老化性、耐臭氧性、耐油性以及玻璃化转变温度等的影响。结果表明,选用助交联剂R153D且其用量为3.5份时,制备的MPU橡胶材料综合力学性能最佳。     

聚醚型聚氨酯性能的影响因素

采用不同种类的聚醚多元醇、二异氰酸酯和扩链剂为原料合成聚氨酯,讨论了聚醚多元醇的相对分子质量、二异氰酸酯的结构、软硬段比例、二异氰酸酯指数、扩链剂种类及用量对聚氨酯性能的影响。结果表明：采用高相对分子质量的聚醚,聚氨酯的定伸强度、拉伸强度和撕裂强度下降,断裂伸长率提高;聚氨酯的性能随硬段含量的增加而提高;异氰酸酯指数控制在1.01~1.03左右;扩链剂链长越短,聚氨酯的微相分离程度和力学性能越好;聚氨酯性能随1、4-丁二醇用量的增加而提高,达到一定用量时反而下降。     

聚醚型聚氨酯混炼胶性能研究

研究了炭黑补强剂和过氧化物（DCP,BIPB）对混炼型聚醚聚氨酯橡胶力学性能的影响,讨论了DCP和补强剂用量变化以及热空气老化对性能的影响。结果表明,DCP硫化胶拉断伸长率高,BIPB硫化胶永久变形低;当DCP用量为1.6份时,拉伸强度和撕裂强度最高,分别为25.3MPa和47.5kN/m;随补强剂用量的增加,混炼橡胶硬度增加,拉伸强度变化不明显,拉伸永久变形变大。     

叠氮聚醚型聚氨酯弹性体材料研究

在叠氮聚醚型聚氨酯弹性体材料研究过程中,以叠氮聚醚为基体材料、TDI为固化剂,在配方中添加癸二酸二异辛酯作为增塑剂、1,4－丁二醇作为扩链剂、辛酸亚锡作为催化剂、白碳黑作为填料,对其配比做了适量的调整。对确定的材料配方进行了加速老化、扩大以及重现性试验。结果表明所研究的叠氮聚醚型聚氨酯弹性体材料性能优良、稳定,能够满足使用要求。     

木素—聚醚型聚氨酯的合成与性能

利用低污染的氧碱制方法制取的麦草氧碱木素合成了木素－聚醚型聚氨酯，对其热性能、力学性能进行了研究。结果表明，麦草氧碱木素可取代部分聚乙二醇与二苯甲基二异氰酸合成木素－聚醚型聚氨酯；异氰酸指数和木素含量对合成的木素－聚醚型聚氨酯性能有影响。     

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。     

聚醚型聚氨酯的氢键、微相分离及性能

用本体一步法合成了5种不同硬段含量(11.0％～46.9％)的二苯甲烷-4,4′-二异氰酸酯/环氧乙烷封端型聚环氧丙烷聚醚/乙二醇的聚醚型聚氨酯,并借助于IR,DSC,DMS和材料试验机等手段对该聚氨酯的氢键、微相分离及力学性能进行了表征。结果表明:随着硬段含量的增加,其>NH与微区中的>C=O的氢键化程度逐渐提高,软段微区中—O—的氢键化程度逐渐降低;微相分离程度逐渐提高;拉伸强度及硬度随之增加,扯断伸长率在硬段含量40％左右出现极大值。     

受阻酚AO-80/聚醚型热塑性聚氨酯弹性体复合材料的结构与性能

用熔融共混法制备了受阻酚AO-80/聚醚型热塑性聚氨酯弹性体(PET-TPU)阻尼材料,通过扫描电子显微镜、X射线衍射分析、差示扫描量热分析及动态力学热分析等研究了复合材料的微现结构、玻璃化转变温度、动态力学性能和力学性能.结果表明,AO-80与基质之间具有良好的相客性,且以分子水平溶解在基质中,处于无定型态.随着AO-80用量的增加,PET-TPU软段的玻璃化转变温度逐渐升高,硬段基本保持不变.AO-80/PET-TPU复合材料的损耗因子与温度曲线呈单峰形式,随着AO-80用量增加其峰值明显增大,并且转变峰向高温方向移动.AO-80的加入使PET-TPU基质的力学性能有所下降.     

Study on shape-memory behavior of polyether-based polyurethanes. I. Influence of the hard-segment content

Shape-memory polyurethanes (PUs) were synthesized by 4,4′-diphenylmethane diisocyanate (MDI), 1,4-butanediol (BD), and poly(tetramethyl oxide)glycol (PTMO). The morphology of PUs was studied using DSC, DMA, and TEM. The results indicated that the PUs would show different morphology by changing the mol ratio of MDI and BD (hard segment). The specimens would show the shape-memory behavior that was fixing and recovering the deformation at different operating temperature ranges. These results demonstrated that the shape-memory behavior of the PUs would be affected by the morphology and the modulus ratio that was defined as in DMA analysis. The amount of the hard-segment-rich phase would affect the ratio of recovery, that is, the low content would lead to the recovery of the deformed specimen being incomplete. The recovering rate would be influenced by the modulus ratio and the size of the dispersed phase in the micromorphology. On the other hand, the shape-memory behavior of PUs could be enhanced by the training process. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1563–1574, 1998     

阻尼橡胶

叙述了阻尼橡胶的发展概况及其性能，阻尼橡胶的主要性能指标为静态刚度，阻尼系数和动态模量，影响阻尼橡胶的最主要因素是橡胶的分子结构。在通用橡胶中，以丁基橡胶和丁腈橡胶的阻尼系数最大，填充体系是除生胶之处影响动态阻尼性能最为显著的因素，与其用量，粒径，活性和形状都有关，阻尼性能亦与硫化体系，增塑剂有关。阻尼橡胶的工艺条件对其性能也有影响，最后介绍了阻尼橡胶的改性方法，共混法，互穿网络法，填充法等。     

聚氨酯种类对机械性能以及阻尼性能影响研究

分别以聚四氢呋喃醚二醇(PTMEG)、聚氧化丙烯二醇(PPG-1000)为软段,以二苯基甲烷二异氰酸酯(MDI-50、MDI-100LL),以及扩链剂1,4-丁二醇(BDO)、三羟甲基丙烷(TMP)为硬段,采用预聚体法制备了聚氨酯弹性体。并系统研究了聚氨酯体系中各组分的种类对材料机械性能和阻尼性能的影响。     

聚酯型聚氨酯阻尼材料的改性研究

采用接枝、嵌段及交联的方法对聚酯型聚氨酯(PU)阻尼材料进行改性并对其阻尼性能和力学性能进行研究.结果表明,PU材料的阻尼性能随接枝率增加而明显提高;当接枝率10%时,tanδmax为0.84,tanδ>0.3的阻尼温域为0.8～61.6℃,拉伸强度19.6 MPa,撕裂强度为27.0 kN/m,伸长率500%,是综合...     

聚氨酯弹性材料阻尼性能的研究

利用粘弹性阻尼结构研究了聚氨酯阻尼材料在0～1000Hz范围内的阻尼性能。制备了不同填料含量的聚氨酯阻尼材料,并用它们构成两种粘弹性阻尼结构,分别测试了两种结构的加速度导纳曲线。测定了不同温度下结构上对应点的加速度导纳,研究结果表明,填料云母含量的增加有利于提高材料的阻尼减振性能,随着温度的升高,材料的阻尼减振性能呈下降趋势。     

浇注型聚氨酯阻尼材料研究进展

从无机填料、互穿聚合物网络(IPN)技术、分子结构设计3个方面分析了目前国内浇注型聚氨酯阻尼材料研发现状,指出分子结构设计是制备高强度、高阻尼、耐动态疲劳性能的聚氨酯阻尼材料的有效方法之一。     

扩链剂对PPG-1000/MDI体系聚氨酯弹性体阻尼性能的影响

以聚氧化丙烯二醇(PPG-1000)、MDI-50与不同的二醇扩链剂采用二步法合成PPG-1000/MDI体系的聚氨酯(PU)弹性体,并对其阻尼性能进行了测试。结果表明,扩链剂对PPG-1000/MDI体系的聚氨酯弹性体的阻尼性能有明显影响。加入含侧甲基和醚键的扩链剂在不同程度上提高了聚氨酯弹性体的阻尼因子(tanδ),拓宽其阻尼温域。因此选择适宜的扩链剂对调节聚氨酯弹性体的阻尼温域具有一定的意义。     

Synthesis,characterization, and permeation properties of polyether-based polyurethanes

A system of synthesis of polyether-based urethanes was developed which had sufficient flexibility in composition so that transport properties could be optimized. Mixtures of poly(oxyethylene) glycol (PEG) and poly(oxypropylene) glycol (PPG) of a variety of molecular weights were tied together by varying amounts of kinds of “hard segments.” Thus, the water swell, the mechanical properties, and the size of the soft blocks and hard blocks could be varied. With a fixed content of hard segments, the water absorption decreased with decrease in the PEG/PPG ratio, demonstrating the feasibility of producing controlled changes in hydrophilicity of the polymer without significant change in the mechanical strength. Some polyurethanes based on PEG 600 and PPG 425 had a very good high value of P_w/P_s but a somewhat low value of P_w. The polyurethanes prepared by using phenylenediamines as chain extenders had markedly enhanced modulus and an extended rubbery plateau region, as anticipated.     

Structure and morphology of segmented polyurethanes: 1. Influence of incompatability on hard-segment sequence length

Separation of three polybutadiene/toluene diisocyanate/butane diol segmented polyurethanes by means of solvent extraction and the characterization of their fractions indicate that the molecules of the original polyurethanes are quite dissimilar in chemical composition and average hard-segment length. These polyurethanes are just blends of two fractions of segmented copolymer with very different average hard-segment content and average hard-segment length. For these polyurethanes, in addition to the segregation of the hard and soft segments, as expected usually for segmented copolymers, the segregation of macromolecules as a whole according to their composition should be considered in the interpretation of their morphology and properties and has been proved to be the origin of the existence of two hard-segment T_g's. This ind of compositional non-uniformity is the result of the poor compatibility between the components of the system. It should be a common phenomenon for segmented copolymers, but is especially obvious in the case of polybutadiene-containing polyurethanes owing to the extremely poor compatibility between their components.