浇注型聚氨酯弹性体在实心轮胎翻新中的应用

试验研究浇注型聚氨酯弹性体(CPUE)在实心轮胎翻新中的应用。结果表明,采用预聚体法,选用二元醇CMA-24、甲基二异氰酸酯TDI和扩链剂MOCA为原料(预聚体中异氰酸酯基质量分数为0.036),在扩链因数为0.88、一段硫化条件为110℃×1h、二段硫化条件为室温×7d的工艺下合成的CPUE胎面胶综合物理性能优良;与全橡胶实心轮胎相比,CPUE胎面翻新实心轮胎的静负荷性能较好,耐磨性能大大提高。     

聚氨酯实心轮胎内生热试验研究

研究聚氨酯实心轮胎的内生热特性。结果表明．以PTMG为软段，TDI-MOCA为硬段、邵尔A型硬度为80～90度之间的聚氨酯弹性体模型负重轮具有良好的耐热性能。轮胎的温升随载荷和转速的增大而升高．环境温度对轮胎的温升有一定影响。     

改性环氧耐磨涂料的性能测定

对聚氨酯改性的环氧耐磨涂料的性能进行测定,采用正交试验法分别测定了制备出的耐磨涂料的附着力、硬度、耐磨性,结果发现聚氨酯改性环氧树脂涂料在不同配比情况下具有不同的硬度、附着力和耐磨性。聚氨酯预聚体的使用,提高了环氧树脂的交联度,明显提高了其耐磨性、附着力和硬度;填料碳化硅和固化剂聚酰胺的使用,能够明显改变环氧树脂的耐磨性、硬度和附着力。     

有机硅改性单组分聚氨酯密封胶的研制及力学性能研究

本文研究了聚氨酯密封胶的预聚体、填料、有机硅等因素对密封胶拉伸强度,伸长率、硬度等力学性能的影响。发现分子结构不同的预聚体与性质不同的填料对其力学性能的影响不同。填料炭黑的补强作用特别强。     

Synthesis and properties of MDI-50 type polyurethane elastomer

以聚醚多元醇和MDI-50为原料,采用预聚物法合成预聚体,再和扩链剂MOCA进行扩链合成聚氨酯弹性体。研究了预聚体中不同异氰酸酯基（—NCO）质量分数对MDI-50型聚氨酯弹性体性能的影响。采用差示扫描量热分析（DSC）、热重分析（TG）、红外光谱（FTIR）及力学性能等测试方法对聚氨酯弹性体的结构与性能进行了表征和分析。结果表明：预聚体反应体系中NCO/OH摩尔比增大,预聚体中—NCO质量分数增加,预聚体的黏度降低,相应的聚氨酯弹性体的硬度和玻璃化转变温度提高,断裂伸长率降低,而拉伸强度和撕裂强度先增加后下降;当NCO/OH摩尔比为2.22时,聚氨酯弹性体力学性能较好;—NCO质量分数对聚氨酯弹性体的热稳定性影响不大。     

聚氨酯-环氧树脂弹性体的合成

首先由聚醚(PPG)和甲苯二异氰酸酯(TDI)反应制得含有端异氰酸酯的预聚体,利用预聚体中的异氰酸酯基团与环氧树脂上的仲羟基反应合成端环氧基团的聚氨酯-环氧树脂,然后用低分子聚酰胺固化.通过改变预聚体中PPG3031含量和NCO/OH的比值得到不同的拉伸强度和硬度.实验结果表明:随着预聚体中PPG3031含量的增大,弹性体的拉伸强度增大,硬度也增大;随着预聚体中NCO/OH摩尔比的提高,弹性体的拉伸强度和硬度增大,断裂伸长率变化不大.     

聚氨酯实心轮胎的研究进展

介绍聚氨酯(PU)实心轮胎的研究及应用进展状况。PU实心轮胎大体上分为全聚氨酯弹性体(PUE),外层为PUE、内层为其它橡胶以及内层为PUE、外层为其它橡胶3种结构,一般采用浇注成型/注射成型和反应注射成型的工艺方法成型;改进原材料或对PUE进行改性可以提高其性能,从而提高PU实心轮胎的性能;PU实心轮胎存在内生热大、成型工艺需改进、成本高等问题。指出PU实心轮胎性能优异,成型工艺简单,发展前景广阔。     

扩链剂对PTMG／MDI体系聚氨酯弹性体力学性能的影响

将聚四氢呋喃均聚醚（PTMG）和4,4’－二苯基甲烷二异氰酸酯（MDI）合成预聚体,分别与BDO、KC、MOCA及HQEE等扩链剂制备了聚氨酯（PU）弹性体。讨论了预聚体NCO基含量、扩链剂种类及三元醇含量对聚氨酯弹性体力学性能的影响。实验结果表明：当预聚体NCO基含量基本相同时,BDO－PU比KC—PU的硬度高1～2度,撕裂强度高了7％～18％;提高预聚体NCO基含量可使聚氨酯弹性体的硬度、撕裂强度和300％模量急剧增加;扩链剂中的三元醇含量超过30％,弹性体的拉伸强度显著下降;预聚体NCO基含量在6．0～6．8下,MOCA－PU的硬度和300％模量很高;HQEE／KC—PU比HQEE—PU的硬度降低了2-4个单位,而拉伸强度却提高了60％～90％。     

端烷氧硅基聚氨酯预聚体及其密封胶的制备

采用聚醚二元醇与二异氰酸酯进行扩链反应合成了端异氰酸酯基聚氨酯预聚体,然后以活性较低的仲胺基硅烷为封端剂,将其转变为端基为三烷氧硅基的聚氨酯预聚体,通过红外光谱表征了预聚体结构,探讨了聚醚二元醇摩尔质量、异氰酸酯基与羟基物质的量之比、二异氰酸酯种类对预聚体性能的影响,还在较佳条件下制得端烷氧硅基聚氨酯密封胶并测试了其性能。结果表明：随着聚醚二元醇摩尔质量的升高,端烷氧硅基聚氨酯预聚体的黏度、密封胶拉伸强度和硬度降低,拉断伸长率提高;随着异氰酸酯基与羟基投料时的物质的量之比(R值)的增大,预聚体的黏度和拉断伸长率降低,拉伸强度和硬度升高;当二异氰酸酯选择二苯基甲烷二异氰酸酯时,与选用异佛尔酮二异氰酸酯时相比,预聚体外观颜色更深,黏度、拉伸强度和硬度更高,拉断伸长率更低;在二异氰酸酯选择二苯基甲烷二异氰酸酯、聚醚二元醇摩尔质量为4 000 g/mol、R值为1.7的较佳条件下制得的端烷氧硅基聚氨酯密封胶表干时间为36 min, 24 h固化深度为2.7 mm,挤出性为270 mL/min,拉伸强度为1.5 MPa,拉断伸长率为230%,邵尔A硬度为34度,综合性能良好。     

充聚氨酯海绵实心轮胎

美国《轮胎商业》2005年6月6日10页报道：美国聚氨酯国际公司推出一种充聚氨酯海绵的实心轮胎。这种聚氨酯海绵的密度仅为传统实心轮胎填充材料的1／3,因此可用于填充较小的轮胎。传统重填充材料由聚氨酯和油组成,它们混合后硫化24h,1m^3的质量约为1025．19kg。这种材料实际上不是海绵,而是含70％油的弹性体,因此非常重。     

填充轮胎用聚氨酯材料的研究

对填充轮胎用聚氨酯材料的配方和性能进行了研究,开发出了原液黏度低、操作时间长并能够常温固化和熟化的填充轮胎用聚氨酯原液;与国外同类材料进行对比,其性能与国外同类材料相当。     

辐板式非充气塑料轮胎静负荷工况下的力学性能分析

提出一种聚氨酯辐板与橡胶胎面相复合的辐板式非充气塑料轮胎,并利用有限元软件ABAQUS在静负荷工况下对相同规格的辐板式塑料轮胎和子午线橡胶轮胎的接地性能和力学性能进行分析和对比。结果表明,相比子午线橡胶轮胎,辐板式塑料轮胎接地印痕形状更合理,沿胎面横向的接地压力分布更均匀,减轻了易发生磨损胎肩的负担;另外,辐板式塑料轮胎径向刚度明显较高,并且在接地区域内的弯曲变形的支撑板起到了缓冲和承载的作用,说明辐板式塑料轮胎具有优越的承载性能和良好的舒适性能。     

Coatings prepared from waterborne polyurethane dispersions obtained with polycarbonates of 1,6-hexanediol of different molecular weights

Waterborne polyurethane dispersions (PUDs) were synthesized with polycarbonates of 1,6-hexanediol of different molecular weight (500–3000 Da) and their properties, adhesion (Hatch adhesion) and coatings on stainless steel properties (Pencil hardness, Persoz hardness, gloss at 60°, chemical resistance, yellowness index) were characterized. The hatch adhesion of the polyurethane coatings to stainless steel was very good and decreased slightly by increasing the molecular weight of the polycarbonate of 1,6-hexanediol. Both the Pencil and Persoz hardness values of the coatings increased by increasing the hard segments content in the polyurethane, i.e. by decreasing the molecular weight of the polycarbonate of 1,6-hexanediol, whereas the gloss and the yellowness index were lower for the coatings obtained with the polycarbonate of 1,6-hexanediol of molecular weight of 500 Da. Very good chemical resistance against ethanol for all polyurethane coatings on stainless steel plates was obtained but for long time of ethanol in contact with the coating surface the chemical resistance decreased, more markedly for the polyurethane coating obtained with the polycarbonate of 1,6-hexanediol of higher molecular weight. In summary, the segmented structure of the waterborne polyurethane dispersion determined the properties of the polyurethane coatings obtained from them.     

合成工艺对木器涂料用水性聚氨酯性能的影响

考察了不同合成工艺对涂膜性能的影响,结果表明:通过合成2种相对分子质量、柔顺性不同的聚酯,进而合成具有高交联度的硬聚氨酯(HPU)和线性软聚氨酯(SPU),并在扩链阶段实现共聚,制备的水性聚氨酯(WPU)的涂膜具有优良的耐干热性、硬度、耐介质性和低温成膜性,成膜助剂用量少,硬度上升快,适合木器装修。     

新型固体胶棒的制备与性能研究

以水性聚氨酯(WPU)乳液为胶粘剂、硬脂酸钠为赋型剂和甘油为保湿剂等制备固体胶棒。采用单因素试验法优选出制备固体胶棒的较佳工艺条件。结果表明:当w(WPU)=25%～35%、w(赋型剂)=5.5%、w(水)=30%～40%、w(保湿剂)=4%、m(硬脂酸)∶m(NaOH)=6∶1、中和反应时间为30 min、中和反应温度为80～85℃和最终体系的pH值为8～9时,固体胶棒具有赋型性好、涂抹性佳、储存稳定期长、粘接性能强、硬度适中、成本较低且环保等优点,完全满足实际使用要求。     

聚氨酯力学性能的研究

本文通过溶液聚合合成聚氨酯（PU），以丁二醇为扩链剂，研究了投料比和投料量对聚氨酯固含量和特性粘度的影响，还考察了聚氨酯中软段和硬段相对含量的变化对力学性能的影响。     

城市轨道列车铝合金车用面漆的研制

研制了高固体含量羟基聚酯树脂，并采用其制备了适合城市轨道列车用高光、耐冲击、硬度高、耐候性强、烟气毒性低、易清洁的聚酯聚氨酯面漆。     

废弃轮胎的热解回收技术

从反应温度、反应时间、催化剂等热解条件对废弃轮胎热解产品产量的影响、热解的产物分析及其应用、废弃轮胎中硫的迁移等方面进行了详细论述。指出反应温度是轮胎热解的主影响因素。热解后,一般得到质量分数为10%～30%的气体、38%～55%的油相产物及33%～38%的固相产物,这些产物均具有较高的热值,可以作为燃料。此外,还可以分离回收液相中的具有较高附加值的化学物质;固相产物以炭黑为主,经处理后可以作为炭黑回用或吸附剂使用。同时还对废弃轮胎热解产物中硫的转化分布进行了讨论。最后对废弃轮胎的其他处理回收技术进行了展望。     

The effect of ultraviolet‐curable water‐borne polyurethane acrylate binder concentration on the printing performance of synthetic leather

In this paper, synthetic leather samples were screen printed with pigmented pastes including two types of photoinitiators and three different concentrations of ultraviolet (UV)‐curable water‐borne polyurethane acrylate binder. The curing process was conducted under different combinations of lamps (gallium, mercury, gallium/mercury and gallium/gallium/mercury) at three power levels. Abrasion resistance, crock fastness, hardness and colour strength were investigated. Chemical changes in the clear and pigmented film structures because of UV curing were analysed by Fourier Transform‐infrared spectroscopy measurements. In hardness measurements, the highest hardness values were obtained with clear and pigmented formulations which have the highest solid content (57%). In colour measurements, higher K/S values were obtained in samples printed with the formulation having a binder concentration of 46%. Wet crock fastness values improved as the energy level increased during curing, and the highest values were obtained with a formulation which had a binder concentration of 57%. Greater amounts of binder in the formulations and increased amounts of energy applied to the surface during curing increased the hardness value of the prints, thus better abrasion resistance was obtained. Overall results suggested that the highest hardness, crock fastness and abrasion resistance values were obtained with the formulation with a binder concentration of 57%. However, for ease of application, printing efficiency and colour strength, the formulation with a binder concentration of 46% is recommended for printing, and curing under consecutive passes with gallium and mercury lamps at 120 W/cm is proposed in terms of energy efficiency and printing performance.     

Cycloaliphatic polyester based high solids polyurethane coatings: I. The effect of difunctional alcohols

High-solids polyesters were synthesized with two cycloaliphatic diacids, 1,4- cyclohexanedicarboxylic acid (1,4-CHDA) and 1,3-cyclohexanedicarboxylic acid (1,3-CHDA); and with five diols, 1,4-cyclohexanedimethanol (CHDM), neopentyl glycol (NPG), hydroxypivalyl hydroxypivalate (HPHP), 2-butyl-2-ethyl-1, 3-propanediol (BEPD), and 1,6-hexanediol (HD). The viscosity of the polyesters was dependent on the structures of diols. The viscosity of polyesters is lower with the diol HD, intermediate with BEPD and HPHP, and higher with the diols CHDM and NPG. The polyesters were crosslinked with hexamethylene diisocyanate isocyanurate (HDI isocyanurate) affording polyurethane coatings. The mechanical properties, tensile properties, fracture toughness, and viscoelastic properties were investigated for the polyurethane films with five different diols. The cyclohexyl structure of the CHDM provides the polyurethane with rigidity which is manifested in high tensile modulus, hardness, and fracture toughness. In contrast, the linear diol, 1,6-hexanediol provides polyurethane with very high flexibility, but these coatings suffer with respect to low hardness and tensile modulus. Polymers and Coatings Department, Fargo, ND 58105. 3401 Grays Ferry Avenue, Philadelphia, PA 19146.