半硬质聚氨酯泡沫塑料的研究(二)——关于半硬泡填充料的研制

由聚醚、多元醇、异氰酸酯及助剂等反应合成的聚氨酯泡沫塑料,随着分子链交联密度的增加,亦即交联点之间分子量(Mc)的降低,其泡沫机械性能迅速提高,而伸长性,压缩变形及在溶剂中溶胀性迅速下降。以泡沫的 Mc 分类,聚氨酯泡沫可分为软泡、硬泡和半硬泡三大类。半硬泡是由软泡向硬泡过渡的中间制品。一般来说,Mc 在400～700时为硬泡,700～2500称为半硬泡,2500～     

纳米材料改性聚氨酯泡沫的研究进展

论述了将纳米材料与聚氨酯泡沫材料复合的研究进展,介绍了常用纳米材料的改性方法。综述了纳米材料对聚氨酯软泡、硬泡、半硬泡复合材料各项基本性能的影响。     

1990—1991年国外聚氨酯工业进展

介绍国外聚氨酯工业进展。内容包括聚氨酯软泡、半硬泡和硬泡的产量及应用消费分配,对CFCs替代品和无CFC_s发泡工艺和阻燃技术等作了论述。     

海底用喷涂聚氨酯硬泡保温配重管的节点补口技术

针对海洋油气输送用聚氨酯硬泡喷涂保温配重管铺设过程中节点补口进行改进研究,介绍了一种聚氨酯硬泡喷涂保温配重管节点结构和施工工艺。主要采用聚氨酯硬泡保温半瓦和浇注聚氨酯弹性体进行节点补口,节点补口性能测试验证效果良好,满足海底油气管道铺设要求。     

影响聚氨酯包装材料超低密度性能的因素

超低密度聚氨酯泡沫,分硬泡,软泡和半硬泡。尤其是半硬泡用于包装,在国外早已获得商品化应用,对某些产品是指定的包装材料。80年代初期,自由发泡密度是8-10kg/m~3,中期是4-8kg/m~3,近年来少数情况下已达2kg/m~3。使用聚氨酯泡沫的主要优     

聚氨酯泡沫塑料高效节能外墙保温技术

阐述了聚氨酯泡沫塑料的高效节能外墙保温技术及喷涂聚氨酯硬泡外墙保温系统、浇注聚氨酯硬泡外墙保温系统、粘贴聚氨酯硬泡外墙保温系统、外挂聚氨酯硬泡外墙保温系统和聚氨酯硬泡复合板外墙外保温系统的施工工艺及特点。     

全水发泡聚碳型聚氨酯问世

中科院广州化学研究院以二氧化碳和环氧丙烷作为原料,制备了相对分子质量3000左右、分子中碳酸酯基团的摩尔分数在30％～40％的聚碳酸酯多元醇,并采用此原料以及全水发泡的方法制备出脂肪族聚碳型聚氨酯半硬泡塑料。这种半硬泡聚氨酯与传统的半硬泡塑料相比,强度和密度都要高。由于该泡沫体中含有大量的-COO结构单元,     

汽车座椅用异氰酸酯市场分析

一、汽车用聚氨酯现状 汽车用聚氨酯主要有：软泡、半硬泡及弹性体异氰酸酯原料以聚合MDI为主：软泡主要为TDI／聚合MDI混合体,少量使用纯TDI及改性MDI体系。以平均每辆车20公斤聚氨酯为基,泡沫类总量约为12—13公斤,其中半硬泡类2-3公斤,软泡9-10公斤,以异氰酸酯：聚醚1：2比例计算,异氰酸酯原料辆车单耗约为3公斤左右。     

聚氨酯硬泡外墙隔热保温技术

本文阐述了喷涂聚氨酯硬泡外墙保温系统,浇注聚氨酯硬泡外墙保温系统,粘贴聚氨酯硬泡外墙保温系统,外挂聚氨酯硬泡外墙保温系统的施工工艺及特点。     

建筑节能保温领域聚氨酯硬泡材料的绿色商机

硬质聚氨酯泡沫塑料,简称聚氨酯硬泡,它在聚氨酯制品中的用量仅次于聚氨酯软泡。聚氨酯硬泡,是由硬泡聚醚多元醇(聚氨酯硬泡组合聚醚又称白料),与聚合MDI(又称黑料)反应制备的。主要用于制备硬质聚氨酯泡沫塑料,广泛应用于冰箱、冷库、喷涂、太阳能、热力管     

Two in One: Modified Polyurethane Foams by Dip‐Coating of Halloysite Nanotubes with Acceptable Flame Retardancy and Absorbency

Poor flame retardancy of polyurethane foam (PUF) limits its practical application in many fields. Here, flame‐retardant performance of PUF is improved by a simple dip‐coating method. Halloysite nanotube (HNT) coating can be uniformly bonded to PUF surfaces via hydrogen‐bonding interactions, which is confirmed by element mapping and X‐ray photoelectron spectra. Density and mechanical properties of PUF increase with the concentration of HNT suspension, while porosity of the foam decreases with HNT loading. Weight ratio of HNTs to PUF in the composite can be achieved as high as 65.2%. Surfaces of PUF transfer from hydrophobic to super‐hydrophilic after HNT coating, and the water contact angle decreases from 116° to 0° after HNT coating. As a result, methylene blue adsorption capacity of HNTs‐coated PUF increases from 0.02 to 0.15 mg g^?1, and adsorption efficiency can reach 98% after 10 s. HNT coating can prevent PUF from burning and dripping, which suggests that flame‐retardant performance of PUF is significantly improved by HNTs. This work establishes a general procedure for improving flame retardancy and dye absorbency of polymer materials by simple dip‐coating of environmental‐friendly clay nanotubes, which shows great potential in high‐performance polymer and functional composite materials.     

Electrical conductivity and EMI shielding effectiveness of polyurethane foam–conductive filler composites

The morphological, electrical, and thermal properties of polyurethane foam (PUF)/single conductive filler composites and PUF/hybrid conductive filler composites were investigated. For the PUF/single conductive filler composites, the PUF/nickel‐coated carbon fiber (NCCF) composite showed higher electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE) than did the PUF/multiwall carbon nanotube (MWCNT) and PUF/graphite composites; therefore, NCCF is the most effective filler among those tested in this study. For the PUF/hybrid conductive fillers PUF/NCCF (3.0 php)/MWCNT (3.0 php) composites, the values of electrical conductivity and EMI SE were determined to be 0.171 S/cm and 24.7 dB (decibel), respectively, which were the highest among the fillers investigated in this study. NCCF and MWCNT were the most effective primary and secondary fillers, and they had a synergistic effect on the electrical conductivity and EMI SE of the PUF/NCCF/MWCNT composites. From the results of thermal conductivity and cell size of the PUF/conductive filler composites, it is suggested that a reduction in cell size lowers the thermal conductivity of the PUF/conductive filler composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44373.     

Polyisobutylene-based urethane foams. II. Synthesis and properties of novel polyisobutylene-based flexible polyurethane foams

Novel polyisobutylene-based flexible polyurethane foams (PIB–PUF) have been prepared manually by the prepolymer method using three-arm star hydroxyl-terminated polyisobutylenes (PIB–triols) and toluene diisocyanate (TDI). Solvent extraction and IR spectroscopy of PIB–PUFs indicated essentially complete crosslinking. Conventional polyether-based polyrethane foams (PE–PUFs) and polybutadiene-based polyurethane foams (PBD–PUFs) have also been prepared by the same method and select physical-mechanical properties of all these urethane foams, such as tensile strength, elongation, resilience, water permeability, hot air stability, and hydrolytic stability, have been examined and compared. Although the density of PIB–PUF is lower than that of PE–PUF, its tensile strength is superior to the latter. Elongation of PIB–PUF is almost the same as those of the other foams. The PIB–PUF exhibits low resilience which indicates good damping properties. Due to the hydrophobicity of the soft segment, PIB–PUF exhibits very low water permeability. The hydrolytic and hot air stability of PIB–PUFs are outstanding. Attempts have been made to determine gas permeabilities; however, due to the open-cell nature of the foams, these studies could not be completed. The new PIB-based urethane foams combine excellent thermal, environmental, barrier, and mechanical properties, unmatched by conventional PUFs.     

Preparation of polyurethane foam fine polishing wheel for stainless steel surface

Comparing with dry polishing, the wet-polishing of the stainless steel surface can significantly reduce dust, noise and other pollution, and improve the polished quality. Thus, it is important to develop new polishing tools. In this work, the effects of the foaming agent and diluents on the mechanical properties of the polyurethane foam (PUF) system were investigated, and then the effect of the filler of graphite on the structure and mechanical properties of PUF was studied. Furthermore, the PUF fine polishing wheel with aluminum oxide was prepared. Results show that the bi-component diluents combined cyclohexane and dimethylformamide significantly affects the porosity and hardness of the PUF matrix. The filler of graphite can decrease the mechanical properties of the polyurethane matrix and increase the porosity of PUF, consequently, improve the self-sharpening of the PUF polishing wheel. The PUF fine polishing wheel with aluminum oxide shows fine polishing performance.     

聚氨酯软质泡沫的制备、孔结构和排油性能

以聚醚多元醇PPO330和甲苯二异氰酸酯为原料,采用一步法发泡工艺,制备了两种催化剂用量不同的聚氨酯软质泡沫(PUF),研究了它们的孔结构和排油性能。结果表明,PUF的泡孔结构较为规整且泡壁表面光滑均匀。其中PUF–1的孔径较大且开孔率较高,两种PUF的孔隙率都在97%以上;PUF–1,PUF–2对喷气燃料和军用柴油的吸油倍率均随着时间的增大而增大,最后达到最大吸油倍率(Q_(max));对喷气燃料的Q_(max)分别为29.48 g/g和23.76 g/g,对军用柴油的Q_(max)分别为32.62 g/g和25.24 g/g;PUF对军用柴油的离心排油率均达到25%左右,但PUF–2对喷气燃料的离心排油率达35.39%以上;PUF对喷气燃料和军用柴油的排油速率均随压强增大逐渐增大,油残存率则逐渐降低。当压强增大到6.23 k Pa时,PUF对两种油品的排油速率达到最大,油残存率均保持在40%以下。     

Biobased flexible polyurethane foams manufactured from lactide-based polyester-ether polyols for automotive applications

In this study, biobased polyester-ether polyols derived from meso-lactide and dimer acids were evaluated for flexible polyurethane foams (PUF) applications. Initially, the catalyst concentration was optimized for the biobased PUF containing 30% of biobased polyol (70% petroleum-based polyol). Then, the same formulation was used for biobased PUF synthesis containing 10%–40% of biobased polyols. The performance of biobased PUF was compared with the performance of the control foam made with 100% petroleum-based polyol. The characteristic times (cream, top of the cup, string gel, rise, tack-free) of biobased PUF were determined. The biobased PUF were evaluated for the mechanical (tensile and compressive) and morphological properties. As the wet compression set is important for automotive applications, it was measured for all biobased PUF. The thermal degradation behavior of biobased PUF was also evaluated and compared with the control foam. The effect of different hydroxyl and acid values of polyols on the mechanical properties of biobased PUF is also discussed. The miscibility of all components of PUF formulations is crucial in order to produce a foam with uniform properties. Thus, the miscibility of biobased polyols with commercial petroleum-based polyol was studied.     

The influence of nano-silica on the thermal conductivity of polyurethane foam

This study reports the influence of nano-silica particles (0.0–0.45 %wt) on properties of polyurethane foams (PUF) using monoglycerides, sorbitol, and glycerol as components of polyol. The morphology, density, mechanical, thermal stability, and thermal conductivity properties of samples were investigated in this study. When 0.35 %Wt of nano-silica was used to reinforce PUF, the compression strength of PUF achieved the highest value (82.49 kPa). The thermal gravimetric analysis showed that the presence of nano-silica can improve the thermal stability of PUF samples. Scanning electron microscopy studies indicated that PUF samples containing 0.3, 0.35, and 0.45 %Wt of nano-silica had more uniform cell structures than pure PUF sample. Finally, the thermal conductivity of pure PUF and PUF/nano-silica were measured at three different levels of humidity (33% RH, 57% RH and 75% RH) at 25°C. The lowest thermal conductivity value achieved was 0.034 W/mK.     

Use of Polyurethane Foam as the Impaction Substrate/Collection Medium in Conventional Inertial Impactors

Open pore polyurethane foam (PUF) can be used effectively as a substrate for conventional inertial impactors with both high particle collection efficiency and minimal vaporization of semi-volatile particle components. The collection characteristics of PUF as an impaction substrate were studied as a function of PUF density, Reynolds number, impaction substrate diameter, and nozzle-toplate distance. The conventional impaction substrate of the PM_2.5 Harvard Impactor sampler was replaced with the PUF substrate. The use of PUF resulted in significant changes in the collection efficiency curve, with the 50% cut-off size (     

苯酚/尿素/甲醛(PUF)树脂的研究进展

苯酚/尿素/甲醛(PUF)共缩聚树脂是一种新型的木材用胶粘剂,其固化特性和耐热特性与酚醛树脂(PF)十分相似,但生产成本明显降低。对PUF共缩聚树脂的合成方法、反应机理、固化特性和影响因素等研究进展进行了综述。     

PUF树脂的固化动力学研究

为了使PUF树脂得到有效应用,采用傅立叶红外光谱和DSC热分析技术,对PUF树脂进行固化动力学研究。研究表明,合成的PUF共缩聚树脂,主要是通过羟甲基键进行固化反应;结合Kissingger方程和Ozawa方程及不同物质的量比PUF树脂DSC曲线,显示随着F／（P＋U）物质的量比的提高,固化的表观活化能逐渐减小。得出了不同物质的量比的PUF共聚树脂固化反应动力学模型。