表面改性橡胶粒子在胶鞋中的应用

作为汽车“鞋子”的橡胶轮胎,已经过多年的优化而使其具有优异的牵引性能和耐久性能。胶鞋大底胶也同样需要这些性能。然而,诸如易模压成型、密度和颜色等方面的考虑使类似于轮胎的ＳＢＲ配方很难用于大底胶中。一种较新的材料———表面改性橡胶粒子使ＳＢＲ粒子可以混入多种大底胶配方中,包括浇注ＰＵ、ＰＵ泡沫、热塑性ＰＵ和乙烯醋酸乙烯酯泡沫。混入上述橡胶粒子可使胶料既保留ＳＢＲ的性能优点又保留其它原材料的性能优点和易加工性。在其它高聚物中使用表面改性橡胶粒子可提高胶料性能,降低成本。例如在ＰＵ胶料中加入橡胶粒子可使其湿摩擦因数提高２８％;在ＰＵ泡沫中使用表面改性橡胶粒子可使拉伸强度提高４５％,撕裂强度提高２１９％,湿牵引力提高２０％。在大底胶中使用橡胶粒子可提高耐久性、安全性和其它性能。     

淀粉反应接枝聚醚的分散液合成高回弹聚氨酯泡沫塑料

研究了用淀粉反应接枝聚醚的分散液对合成ＰＵ高回弹聚氨酯泡沫塑料的效果,考察了该合成体系各组成对泡沫性能的影响。找到了用该分散液合成ＰＵ高回弹泡沫的配方路线,其主要性能指标达到ＰＵ高回弹泡沫塑料的ＡＳＴＭ标准。     

UOP／Chiyoda醋酸生产新工艺

主要介绍ＵＯＰ／Ｃｈｉｙｏｄａ公司在孟山都公司羰基合成醋酸工艺的基础上联合开发的醋酸新工艺。该技术的主要改进是：改变催化剂体系,由均相反应改为非均相反应;催化剂由液态改为固态（即将催化剂铑固定在特殊的树脂上）;反应器由釜式带搅拌改为泡沫塔式无搅拌;反应器材质可降级为钛材等     

化学交联型PU弹性体网络结构参数M↑—c的理论计算方法

通过对交联固化模型的进一步研究，提出了适用于Ａ４Ａ３Ａ２／Ｂ２型和Ａ３Ａ２／Ｂ４型固化体系Ｍ↑－ｃ的理论计算公式。这些公式在ＰＵ弹性体结构与性能之间关系的研究及ＰＵ泡沫和弹性体等制品的质量控制中，将有广泛的应用。     

化学交联型PU弹性体网络结构参数的理论计算方法

本文提出了适用于Ａ４、Ａ３、Ａ１／Ｂ２型和Ａ３、Ａ２／Ｂ４型固化体系Ｍｃ的理论计算公式。这些公式在ＰＵ弹性体及ＰＵ推进剂结构与性能之间关系的研究和ＰＵ泡沫、弹性体、ＰＵ固体推进剂等制品的质量控制中，将有广泛的应用。这些公式尤其适用于Ｎ－１５高能推进剂的力学性能与固化网络结构的关系研究中。     

泡沫碳化硅的制备及应用

对"泡沫碳化硅基结构催化剂的设计、制备及应用关键技术"的研究过程及所取得的成果进行了综述,介绍了泡沫碳化硅的制备、性能、活性涂层涂覆、规整填料等多方面的工作,并将所得到的泡沫碳化硅结构催化剂在不同的化学反应中进行应用考察。与颗粒催化剂等传统的催化剂进行比较,泡沫碳化硅结构催化剂传热和传质能力强,结构可设计性高。     

汽车制造业对用于泡沫塑料胺催化剂的要求

摘编自Ｕｒｅｔｈａｎｅｓ Ｔｅｃｈｎｏｌｏｇｙ，１９９９，１６（４）：３国外，汽车制造商对用于聚氨酯泡沫塑料的叔胺类催化剂有两方面要求。一是胺类化合物不能从泡沫塑料中逸出而排入汽车内，如大众公司要求泡沫原料供应商在一年内做到这一点。二是防止胺类化合物使汽车部件表层染色，如带ＰＶＣ面层的聚氨酯遮阳板。ＰＶＣ面层变色是长期存在的问题，增加稳定剂用量可减缓变色过程，但因目前用量已至极限，再增加会产生副作用。有关公司对这两方面要求还提出了相应的测试方法。 上述要求，对胺类催化剂生产商来说颇有难度。按Ｅｌａ…     

丙烯酸树脂改性的水性聚氨酯性能与结构

采用丙烯酸树脂（ＰＡ或ＰＡ’）对水性聚氨酯（ＰＵ）改性,研究了丙烯酸树脂改性的水性聚氨酯的性能与结构。结果表明：设计ＰＵ分子链硬段与ＰＡ分子链形成化学键,材料中ＰＵＡ及ＰＵ／ＰＡ中ＰＵ分子链硬段与ＰＡ分子链具有较高的相容性和共混程度;机械共混物ＰＵ／ＰＡ中ＰＵ分子链、ＰＡ分子链之间的共混主要集中于ＰＵ乳胶粒、ＰＡ乳胶粒表层;ＰＵＡ及ＰＵＡ’材料ＰＵ分子链与ＰＡ分子链之间处于一同相分离状态。ＰＵＡ’     

聚氨酯环氧树脂互穿网格的性能研究

本文以Ｎ，Ｎ—二甲基苄胺和二月桂酸二丁基锡为催化剂合成聚氨酯（ＰＵ）环氧树脂（ＥＰ）互穿网络（ＩＰＮ）弹性体，考察了产物的力学性能和热学性能。实验结果表明，ＩＰＮＰＵ／ＥＰ比纯ＰＵ具有更好的物理机械性能及加工性能，拉伸强度得到很大提高，并在ＥＰ含量为２０％时达到最大，而热稳定性有所降低。     

PU的性能及应用

简要介绍了聚酯型ＰＵ和聚醚型ＰＵ的基本性能和合成方法;阐述了从加工方法上所分的３种类型ＰＵ（浇注型ＰＵ、注射型ＰＵ和混炼型ＰＵ）的合成方法和性能特点;列举出ＰＵ的主要用途。     

Mechanical properties of BaTiO3 open-porosity foams

Barium titanate (BaTiO₃) foams synthesized via direct foaming method using silicon-free, rigid polyurethane systems (PU), commercially purchased and lab developed, are being engineered for piezocomposites in sonar applications. The mechanical properties of these foams were measured using confined compression testing to evaluate the suitability of these foams for the intended application. Compressive modulus and collapse strain determined from the experimental data increased with increasing density. Additionally, the foams fabricated using the lab developed PU (LPU) showed a higher mechanical strength due to a higher average density than the foams developed using commercial PU (CPU) system. The data was then fit with a phenomenological model to verify the values of the compressive properties extracted from the experimental data and also to extract additional properties such as tensile strength. Based on these findings, it is proposed that these foams can be successfully incorporated into piezocomposites by infiltrating the foams with polymer.     

Surface‐modifiers of clay on mechanical properties of rigid polyurethane foams/organoclay nanocomposites

Three different surface modifiers, octadecyl trimethyl ammonium (ODTMA), octadecyl primary ammonium (ODPA), and decanediamine (DDA) were used to modify Na⁺? montmorillonite (MMT), and the resultant organoclays were coded as ODTMA‐MMT, ODPA‐MMT, DDA‐MMT, respectively. Rigid PU foams/organoclay composites were prepared by directly using organoclay as the blowing agent without the addition of water. Investigation shows that the morphology of the nanocomposites is greatly dependent on the surface modifiers of clay used in the composites. In detail, DDA‐MMT is partially exfoliated in the PU matrix with the smallest cell size, while two others are intercalated in the PU matrices with smaller cell sizes. The sequence of their cell sizes is pristine PU foams > rigid PU foams/ODTMA‐MMT > rigid PU foams/ODPA‐MMT > rigid PU foams/DDA‐MMT, and the average cell size of rigid PU foams/DDA‐MMT composites decreases evidently from 0.30 to 0.07 mm. Moreover, all rigid PU foams/organoclay composites show remarkable enhanced compressive and tensile strengths as well as dynamic properties than those of PU foams, and the enhancement degree coincides well with the relative extent of internal hydrogen bonding of materials and gallery spacing of organoclay. For example, in the case of rigid PU foams/DDA‐MMT composite, 214% increase in compressive strength and 148% increase in tensile strength compared with those of pure PU foams were observed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Preparation and Characterization of Sustainable Polyurethane Foams from Soybean Oils

Polyol derived from soybean oil was made from crude soybean oil by epoxidization and hydroxylation. Soy-based polyurethane (PU) foams were prepared by the in-situ reaction of methylene diphenyl diisocyanate (MDI) polyurea prepolymer and soy-based polyol. A free-rise method was developed to prepare the sustainable PU foams for use in automotive and bedding cushions. In this study, three petroleum-based PU foams were compared with two soy-based PU foams in terms of their foam characterizations and properties. Soy-based PU foams were made with soy-based polyols with different hydroxyl values. Soy-based PU foams had higher T _g (glass transition temperature) and worse cryogenic properties than petroleum-based PU foams. Bio-foams had lower thermal degradation temperatures in the urethane degradation due to natural molecular chains with lower thermal stability than petroleum skeletons. However, these foams had good thermal degradation at a high temperature stage because of MDI polyurea prepolymer, which had superior thermal stability than toluene diisocyanate adducts in petroleum-based PU foams. In addition, soy-based polyol, with high hydroxyl value, contributed PU foam with superior tensile and higher elongation, but lower compressive strength and modulus. Nonetheless, bio-foam made with high hydroxyl valued soy-based polyol had smaller and better distributed cell size than that using low hydroxyl soy-based polyol. Soy-based polyol with high hydroxyl value also contributed the bio-foam with thinner cell walls compared to that with low hydroxyl value, whereas, petroleum-based PU foams had no variations in cell thickness and cell distributions.     

Flexible polyurethane foams synthesized employing recovered polyols from glycolysis: Physical and structural properties

Polyurethane (PU) is one of the most important polymers with a global production of 17.565 million tons, which makes its recycling an urgent task. Besides, the main goal of PU recycling is to recover constituent polyol as a valuable raw material that allows to obtain new PU with suitable properties. Split‐phase glycolysis can be considered the most interesting PU recycling process since provides high‐quality recovered products in terms of polyol purity. The aim of this work was to evaluate several recovered polyols as replacement of the raw flexible polyether polyol in the synthesis of new flexible PU foams. These recovered polyols come from the split‐phase glycolysis of different types of PU foams and employing as cleavage agents diethylene glycol or crude glycerol (biodiesel byproduct). The influence of the foam waste type and of the cleavage agent on the foams properties was analyzed. The recovered polyols were evaluated by performing several foaming tests according to the method of free expansion foaming of conventional flexible foam. Synthesized flexible foams containing different proportions of recovered polyols were characterized by means of scanning electron microscopy, density and tensile properties; obtaining similar and sometimes even better values compared to the foams manufactured from commercial polyols. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45087.     

Synthesis of a green reactive flame-retardant polyether polyol and its application

The low-flame retardancy properties of pure rigid polyurethane (PU) foams hindered its practical application in many cases for the safety and environmental concern. Although rigid PU foams with flame retardants can achieve standard of fire resistance, addition of flame retardants in PU can worsen its mechanical properties, enlarge production cost, and induce safety problems. Therefore, green reactive flame-retardant polyether polyols (GPP) have been considered as one of the best solutions. In this work, the GPP by the ring-opening polymerization of the self-made environmentally friendly melamine resin (EFMR) with propylene oxide are synthesized with their hydroxyl number of 390 ~ 420 mg KOH/g, and the structure of GPP product was identified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The flame-retardant rigid polyurethane foams (RPUFs) were successfully prepared with GPP as the polyol, the results showed that the addition of GPP can greatly improve the thermal stability and flame retardancy of the RPUFs prepared. The RPUF were prepared by fully GPP with 30.4% of limiting oxygen index and 350 kpa of compressive strength. These properties are qualified for commercial utilization. Therefore, this GPP provides great prospect in the development of specified flame-retardant PU materials.     

Preparation and characterization of microencapsulated ammonium polyphosphate and its synergistic flame‐retarded polyurethane rigid foams with expandable graphite

A facile and effective method for the preparation of microencapsulated ammonium polyphosphate (MAPP) by in situ surface polymerization was introduced. The ‘polyurethane‐like’ shell structure on the surface of MAPP was characterized by using Fourier transform infrared spectroscopy. The hydrophobicity and thermal behavior of MAPP were studied by using water contact angle tests and thermogravimetric analysis. The foam density and mechanical properties of polyurethane (PU) rigid foams were investigated. The flame retardancy of PU rigid foams formulated with MAPP was evaluated by using limiting oxygen index and cone calorimetry. The results show that MAPP can greatly increase the flame retardancy of PU materials. Also, there is a synergistic effect between MAPP and expandable graphite in flame retarding PU rigid foams. Moreover, the water resistance property of PU/MAPP composites is better than that of PU/ammonium polyphosphate. The morphology and chemical structure of PU/MAPP rigid foams after burning were systematically investigated. © 2013 Society of Chemical Industry     

环氧树脂加成多元醇增强聚氨酯软质泡沫塑料

用双酚 A型环氧树脂与乙酸反应,合成了具有刚性骨架的环氧树脂加成多元醇 (EAP),并用 FTIR与 1H－ NMR对其进行了表征。研究结果表明,工业聚醚多元醇中添加 EAP后制备的全水发泡软质聚氨酯（ PU）泡沫塑料的压入硬度显著提高,但回弹性不变。进一步研究了不同水用量对所制备 PU软质泡沫塑料力学性能的影响,并用 FTIR和光学显微镜考察了 PU软质泡沫塑料中脲基的氢键行为和泡孔结构。结果表明,在 PU软质泡沫塑料中引入 EAP刚性链对 PU泡沫塑料的结构及性能有很大影响。     

制备工艺对聚氨酯酰亚胺泡沫性能的影响

以均苯四甲酸二酐(PMDA)、多苯基多亚甲基多异氰酸酯(PAPI)、聚醚多元醇为主要原料,分别采用聚酰亚胺(PI)预聚法、聚氨酯(PU)预聚法和一步法制备聚氨酯酰亚胺泡沫,从微观形貌、力学性能、热稳定性能以及阻燃性能方面对上述3种制备工艺进行对比和评估。实验结果表明,采用一步法制备PUI泡沫时,PU链段和PI链段同时增长,容易造成泡孔缺陷,导致泡沫的力学性能较差;在采用PU预聚法制备的PUI泡沫中,PU链段含量较高,因此,泡孔孔径分布较宽且平均泡孔直径较大,对应的热稳定性和阻燃性能较差;采用PI预聚法制备的PUI泡沫的泡孔孔径分布窄且平均泡孔直径较小,对应的压缩性能、热稳定性以及阻燃性能均达到最佳。     

Physical properties of new polyurethanes foams from benzene polyols synthesized from erucic acid

High density triol‐based polyurethane (PU) foams were developed from aromatic triol isomers prepared from erucic acid. The triol monomers were crosslinked with 4,4′‐diphenylmethane diisocyanate (MDI) into PU foams. The foam's properties were studied by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The foams were analyzed for closed cell content and compression strength. The effect of the benzene ring in the polyol structure on the physical properties of these new PU foams was compared with high density foams made from aliphatic polyols originating from canola oil. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Highly flame‐retardant bio‐based polyurethanes using novel reactive polyols

Poor flame retardancy of polyurethanes (PU) is a global issue as it limits their applications particularly in construction, automobile, and household appliances industries. The global challenge of high flammability of PU can be addressed by incorporating flame‐retardant materials. However, additive flame‐retardants are non‐compatible and depreciate the properties of PU. Hence, reactive flame‐retardants (RFR) based on aliphatic (Ali‐1 and Ali‐2) and aromatic (Ar‐1 and Ar‐2) structured bromine compounds were synthesized and used to prepare bio‐based PU using limonene dimercaptan. The aromatic bromine containing foams showed higher close cell content (average 97 and 100%) and compressive strength (230 and 325 kPa) to that of aliphatic bromine containing foams. Similar behavior was observed for a horizontal burning test where with a low concentration of bromine (5 wt %) in the foams for Ar‐1 and Ar‐2 displayed a burning time of 12.5 and 11.8 s while, Ali‐1 and Ali‐2 displayed burning time of 25.7 and 37 s, respectively. Neat foam showed a burning time of 74 s. The percentage weight loss for neat PU foam was 26.5%, while foams containing 5 wt % bromine in Ali‐1, Ali‐2, Ar‐1, and Ar‐2 foams displayed weight loss of 11.3, 14, 7.9, and 14%, respectively. Our results suggest that flame retardant PU foams could be prepared effectively by using RFR materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46027.