汽车顶棚用热塑性半硬质聚氨酯泡沫的吸声性能研究

通过驻波管传递函数法测试了不同条件下汽车顶棚用热塑性半硬质聚氨酯泡沫的吸声性能。研究结果表明:泡沫吸声系数随密度增加而提高;泡沫厚度对中低频区吸声性能影响较大,吸声系数随厚度增加而提高;高异氰酸酯指数情况下泡沫吸声性能较好;硅藻土的引入可有效提高泡沫的吸声性能;高回弹聚氨酯泡沫与半硬质聚氨酯泡沫复合且高回弹聚氨酯泡沫为吸声面时吸声效果较好。     

聚氨酯泡沫材料吸声频率特性研究

聚氨酯泡沫材料是目前应用较多的一种多孔性吸声材料，其吸声性能不仅与泡孔结构等材料本身性质有关，还与吸声结构和实际使用安装状态有关。本研究主要研讨了研制聚氨酯泡沫及其吸声结构板材的吸声频率特性。研究结果表明，（1）研制聚氨酯泡沫吸声材料具有优良的吸声性能，50mm厚时所测得100-5000HZ范围内的驻波管法平均吸声系数可达到0．51；（2）利用共振吸声原理来组装聚氨酯泡沫芯吸声结构可有效地调节材料的吸声频率特性；（3）在聚氨酯泡沫芯吸声结构中，将泡沫芯做成狭缝结构和尖劈结构，还可进一步拓展其吸声频率特性。     

纤维/聚氨酯泡沫复合材料的制备及吸声性能研究

通过热压发泡法制备了一系列竹粉、木粉、改性木粉纤维/聚氨酯泡沫复合材料,研究了不同填料及填料含量对聚氨酯发泡复合材料吸声性能的影响。添加纤维的聚氨酯泡沫复合材料吸声峰向低频移动,吸声性能有所提高。     

磁场取向镀镍碳纳米管/聚氨酯复合泡沫材料的制备及性能

在磁场作用下通过一步法原位聚合制备了磁场取向镀镍多壁碳纳米管/聚氨酯复合泡沫材料.通过透射电镜、扫描电镜等表征了泡沫材料的结构,并测试了材料的压缩性能和吸声性能.结果表明:镀镍碳纳米管可使聚氨酯泡沫材料的泡孔更均匀.在磁场作用下,镀镍碳纳米管取向能显著提高材料的压缩强度,当碳纳米管的质量分数为1.0%时,其压缩强度为纯PU泡沫材料的3倍.同时,取向镀镍碳纳米管/PU复合泡沫材料的吸声性能也得到了进一步提高.     

汽车隔音垫用聚氨酯软质高回弹泡沫的吸音性能研究

通过驻波管法测试不同隔音垫聚氨酯软质高回弹泡沫的吸声系数,结合显微镜对泡沫的力学特性和形态进行观察和分析。研究结果表明,泡沫在低频区的吸声系数随厚度的增加而提高,而在高频区则有所减弱;泡沫的吸声系数随密度增加而提高;泡孔形态对泡沫的吸声性能有显著影响,细密而均一的泡孔有利于声能的吸收;不同异氰酸酯由于反应性和结构上的差异,泡沫也表现出不同的吸声特性;高压发泡生产的泡沫峰值吸声频率稍向高频区移动,复合乙烯–醋酸乙烯共聚弹性体（EVA）后泡沫的峰值吸声频率稍向低频区移动。     

聚酰亚胺泡沫材料吸声性能对比研究

通过阻抗管法研究了聚酰亚胺(PI)、三聚氰胺(MFF)和聚氨酯(PU)3种泡沫材料对声音的吸收特性。结果表明:与MFF和PU泡沫材料相比,PI泡沫材料具有优异的吸声降噪性能;随着材料密度的增大,3种泡沫的吸声降噪性能都有相应提高。     

填充蜜胺泡沫芳纶蜂窝复合芯吸声性能研究

制备了蜜胺泡沫填充芳纶蜂窝复合芯,分析了复合芯的吸声机理,考察了复合芯的密度和厚度对吸声性能的影响。结果表明,在较高频率范围内,复合芯的吸声系数高于蜜胺泡沫;随着复合芯的密度及厚度的增大,复合芯在低频下的吸声性能逐步增大;当复合芯密度和厚度分别为78 kg/m3及20 mm,其平均吸声系数可达0.61,是一种优异的工程吸声材料。     

一种新型吸声材料的结构设计及其吸声性能研究

以聚醚多元醇和异氰酸酯为原料,通过一步法制备了聚氨酯泡沫(PU),将PU与微穿孔板(MPP)结合起来,制备了一种新型层状吸声结构。分别研究了穿孔率、空腔深度、材质及MPP厚度对其吸声性能的影响。结果表明:所设计的新型层状吸声结构具有良好的吸声性能,所设计的吸声结构在空腔厚度为20mm时具有最佳吸声性能。     

纳米二氧化硅/聚氨酯酰亚胺复合泡沫材料的制备与性能

采用预分散法和一步法制备了纳米SiO2/聚氨酯酰亚胺(PUI)复合泡沫材料,考察了纳米SiO2对PUI发泡过程的影响,研究了纳米SiO2/PUI复合泡沫材料的泡孔结构及性能。结果表明,在PUI发泡过程中,随着纳米SiO2用量的增加,复合泡沫材料的开孔率增大,可有效防止泡沫收缩,且密度也减小;当纳米SiO2用量为10份时,纳米SiO2/PUI复合泡沫材料具有比较均匀的泡孔结构,且具有较高的开孔率、良好的阻燃性和热稳定性;柔软性泡沫还具有较好的吸声性能     

乙二醇醚化改性三聚氰胺树脂对软质聚氨酯吸音泡沫性能的影响

用乙二醇醚化改性三聚氰胺合成了分子结构中含有三嗪环的羟基封端改性剂乙二醇醚化三聚氰胺(EGEMF),制备了软质聚氨酯泡沫材料。发现当w(EGEMF) 8%时,能有效地改善聚氨酯泡沫材料的吸声性能、力学性能及耐热阻燃性能。     

Rigid polyurethane foams based on activated soybean meal

Soybean meal (SM), an abundant biomass resource, was used as the surrogate to partially replace polyols in rigid polyurethane foam synthesis. Compared with polyurethanes based on other soybean‐based resources, such as soybean protein isolate (SPI), polyurethane foams based on activated SM showed better thermal and mechanical properties. The amount of SM in the final polyurethane foams can be as high as 30 wt % (base on the total weight of foam), which dramatically decreases the cost of the foams. The results also showed that SM played a vital role in improving the foam properties, which could be attributed to the participation of the functional groups in SM in the polyurethane foam synthesis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

水声吸声材料研究进展

水声吸声材料常用于水下航行体表面,其研究对于水下目标的声隐身设计具有重要意义,在军事应用领域受到广泛关注。橡胶类和聚氨酯类粘弹性高分子材料因其独特的分子结构和可设计性得到广泛应用,此外吸声材料的结构设计对其性能也有着很大影响。本文在水声吸声材料吸声机理的基础上,对其主要材料体系和吸声结构进行了综述。     

Reinforcement of soy polyol‐based rigid polyurethane foams by cellulose microfibers and nanoclays

Water‐blown rigid polyurethane foams from soy‐based polyol were prepared and their structure–property correlations investigated. Cellulose microfibers and nanoclays were added to the formulations to investigate their effect on morphology, mechanical, and thermal properties of polyurethane foams. Physical properties of foams, including density and compressive strength, were determined. The cellular morphologies of foams were analyzed by SEM and X‐ray micro‐CT and revealed that incorporation of microfibers and nanoclays into foam altered the cellular structure of the foams. Average cell size decreased, cell size distribution narrowed and number fractions of small cells increased with the incorporation of microfibers and nanoclays into the foam, thereby altering the foam mechanical properties. The morphology and properties of nanoclay reinforced polyurethane foams were also found to be dependent on the functional groups of the organic modifiers. Results showed that the compressive strengths of rigid foams were increased by addition of cellulose microfibers or nanoclays into the foams. Thermogravimetric analysis (TGA) was used to characterize the thermal decomposition properties of the foams. The thermal decomposition behavior of all soy‐based polyurethane foams was a three‐step process and while the addition of cellulose microfibers delayed the onset of degradation, incorporation of nanoclays seemed to have no significant influence on the thermal degradation properties of the foams as compared to the foams without reinforcements. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Biodegradable polyurethane foam from liquefied waste paper and its thermal stability,biodegradability, and genotoxicity

Liquefaction of waste paper (WP) was conducted in the presence of polyhydric alcohols to prepare biodegradable polyurethane foam. The liquefied‐WP‐based polyol had suitable characteristics such as apparent molecular weight, hydroxyl value, and viscosity for the preparation of rigid polyurethane foam and was successfully applied to produce polyurethane foam with the appropriate combinations of foaming agents. The obtained foams showed satisfactory densities and mechanical properties as good as those of foams obtained from liquefied wood‐ and starch‐based polyols. The foams had almost the same thermal stability at initial weight loss and seemed to be potentially biodegradable because they were degraded to some extent in leaf mold. There were no mutagens or carcinogens in the water extracts of the foams. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1482–1489, 2002     

Reticulated vitreous carbon from polyurethane foam-clay composites

Reticulated vitreous carbon foams were prepared by carbonizing polyurethane precursor foams which were first infused with furfuryl alcohol. The cell size and the fraction of open cells of the precursor foam were controlled by the addition of clay in the polyurethane foam formulation. Addition of clay permitted control of the cell size of carbon foams. The higher open cell content in foams with clay permitted uniform infusion of furfuryl alcohol in the precursor, and thus more uniform carbon foams of higher density. These foams had a lower electrical resistance as compared to foams without clay.     

聚氨酯泡沫塑料在低密度炸药制备中的应用

以软质聚氨酯泡沫塑料为载体，制备低密度炸药。探讨了聚氨酯泡沫塑料在低密度炸药中的应用。简单介绍了采用炸药溶液浸渍法、水分散液浸泡法和原料混合发泡法这三种方法的工艺过程以及产品的爆炸性能。     

双负载抗生素亲水性聚氨酯泡沫的制备与表征

因细菌、异物和炎症等因素引起的慢性伤口会有过量的伤口渗出液流出,影响伤口周围健康皮肤,不利于伤口愈合.针对以上问题,我们开发了双负载亲、疏水性抗生素的亲水性聚氨酯泡沫作为慢性伤口的创面敷料.通过电子显微镜观察,泡沫的孔径均匀地分布在200～400 μm之间.聚氨酯泡沫中载入的药物对聚氨酯泡沫的力学性能略有影响,对吸液率...     

Mechanical Properties and Flame Retardancy of Rigid Polyurethane Foams Containing SiO2 Nanospheres/Graphene Oxide Hybrid and Dimethyl Methylphosphonate

Halogen-free flame-retardant rigid polyurethane foams were prepared using the combination of SiO₂ nanospheres/graphene oxide hybrid and a phosphorus-containing flame retardant, dimethyl methylphosphonate. The flame retardancy, mechanical, and thermal properties of flame-retardant rigid polyurethane foams containing dimethyl methylphosphonate and SiO₂ nanospheres/graphene oxide were investigated. The results demonstrated that the combination of dimethyl methylphosphonate and SiO₂ nanospheres/graphene oxide enhanced flame retardant and mechanical properties of rigid polyurethane foam greatly compared with pure rigid polyurethane foam and dimethyl methylphosphonate-modified foam. Morphological study indicated that the partial substitution of dimethyl methylphosphonate with SiO₂ nanospheres/graphene oxide led to smaller cell sizes and more uniform cell sizes of dimethyl methylphosphonate-modified rigid polyurethane foams.     

模板预处理对泡沫炭结构的影响

以聚氨酯泡沫为模板,糠醇为碳源,采用模板法制得块状泡沫炭材料,扫描电镜(SEM)观察发现：产品是由大孔组成的、具有网状结构的多孔材料。研究了不同炭化终温对产品形貌、残炭率和体积收缩率的影响;考察了对模板聚氨酯泡沫进行NaOH水解预处理的条件,即水解时间、水解温度和碱液浓度对模板及产品结构的影响。结果表明,模板的预处理去除了聚氨酯泡沫闭孔上的隔膜,提高了泡沫的浸渍能力,制得了具有更高开孔率、残炭率以及体密度的产品,说明模板预处理是改善产品结构和性能的有效手段。     

高强度聚氨酯硬质泡沫制备技术的发展现状与展望

讨论了影响聚氨酯硬质泡沫塑料强度的重要因素,并介绍了聚氨酯硬质泡沫塑料的增强技术,重点综述了混杂增强和纳米增强的研究进展。