国产聚合MDI在冰柜保温上的应用

通过自由发泡和模具压力发泡，对国产聚合MDI(PM-2010)的反应活性、所制备泡沫制品的性能及其在冰柜制冷方面的性能等进行了测试和比较，确认了国产聚合MDI的综合性能与常用的几种进口牌号基本相当，从而确认了其在冰柜领域使用的可行性。     

傅克法合成二苯甲烷的研究进展

综述了近年来傅克法合成二苯甲烷的研究进展,包括均相催化剂、负载型酸催化剂、固体酸催化剂和氧化型催化剂等。对各类催化剂在反应中的性能及影响因素进行了探讨,并对傅克法合成二苯甲烷催化剂未来的研究趋势进行了展望。     

Construction of functional aliphatic polycarbonates for biomedical applications

Aliphatic polycarbonates are one important kind of biodegradable polymers and have been commonly used as integral components of engineered tissues, medical devices and drug delivery systems. As far as the biomedical application is concerned, traditional aliphatic polycarbonates usually suffer from the strong hydrophobicity, deficient functionality, and insufficient compatibility with cell/organs. Consequently, the application is quite limited in scope. Due to the imparted appealing properties, aliphatic polycarbonates bearing specifically designed functional/reactive groups attract great interest from researchers in the recent years. The present review outlines the development up to date concerning the design and biomedical application of functional aliphatic polycarbonates, with an emphasis on their ring-opening (co)polymerization preparation.     

二苯甲烷双马来酰亚胺的合成工艺研究

以顺丁烯二酸酐和4,4'-二氨基二苯基甲烷(DDM)为原料,采用甲苯为溶剂、共沸蒸馏法,分别用一步法和两步法合成N,N'-4,4'-二苯甲烷双马来酰亚胺(BDM)。通过产物核磁氢谱、红外色谱、示差扫描量热(DSC)及产物收率的计算和双键含量、酸值、凝胶时间、凝胶温度等的测定,对BDM一步法、两步法合成工艺进行了研究并对两种方法中生成的副产物进行了分析。结果表明,一步法比两步法产品产率有很大提高,得到的残渣较少,主要是由DDM与BDM的加成反应生成的低聚物,重新利用价值较小;两步法副产物较多,如高温条件下BMA发生分子间脱水形成的线形低聚物,其可以水解成BMA重新利用。     

热塑性聚氨酯合成过程中平均相对分子质量的变化

采用转矩流变仪模拟双螺杆挤出反应,分别在无催化剂和铋/锌复合催化剂作用下进行4,4′/2,4′二苯基甲烷二异氰酸酯/聚四氢呋喃醚二醇/1,4丁二醇本体聚合,合成热塑性聚氨酯(TPU)。在聚合过程中取样并采用凝胶渗透色谱法测定TPU的平均相对分子质量,根据重均相对分子质量与反应速率常数和时间的关联式,得到无催化剂作用下TPU重均相对分子质量与反应温度和反应时间的关联式,以及有催化剂作用下TPU重均相对分子质量与反应温度、反应时间及催化剂浓度的关联式。采用所得动力学参数拟合反应过程中TPU重均相对分子质量的变化,拟合结果与实验值吻合良好。     

Synthesis and characteristics of thermoplastic elastomer based on polyamide‐6

A new class of polyether amide thermoplastic elastomers (TPAE) was synthesized via a three‐step polymerization route. In the first step a binary carboxyl terminated polyamide‐6 (PA6) with relatively low number‐average molecular weight was prepared via a caprolactam hydrolytic ring‐opening process. 4,4′‐Diphenylmethane diisocyanate (MDI) was reacted with the PA6 to produce PA6–MDI hard segments in the second step. Chain extension of the hard segments with poly(tetramethylene glycol) was the last step to furnish a series of new TPAEs. Structural characterization, physical properties and the effects of reaction conditions on the properties of the copolymer were investigated by infrared spectroscopy, ¹H nuclear magnetic resonance spectroscopy and other analytical techniques. Possible side reactions and phase separation are reported. Copyright © 2011 Society of Chemical Industry     

Synthesis and Properties of a Novel Linear Alkylated Diphenylmethane Sulfonate Gemini Surfactant

The linear alkylated diphenylmethane sulfonate (C₁₂‐DSDM) was synthesized by a four‐step reaction with lauric acid, diphenylmethane and chlorosulfonic acid as raw materials. The structure of the final product was characterized by MS. The air–liquid surface tensions at various temperatures and salt solutions (NaCl) were measured by using the drop‐volume technique and the thermodynamic parameters of the micellization were calculated. The results show that the critical micelle concentration (CMC) and γ_CMC of the surfactant are 1.452 mmol L^?1 and 38.49 mN m^?1 at 298 K. With an increase in temperature, the CMC gradually increases, the γ_CMC and the maximum surface adsorption capacity Γ_max decrease. The free energy of micelle formation is negative (?51.2 to ?60.5 kJ mol^?1).     

改性麦草氧碱木素在聚氨酯合成中的应用

将麦草氧碱木素与环氧丙烷反应得到改性木素，其酚羟基和醇羟基含量增加，提高了木素与二异氰酸酯的反应性能；利用改性木素取代部分聚乙二醇与异氰酸酯合成了聚氨酯，并对热性能和机械性能进行了研究。结果表明，异氰酸酯指数和改性木素含量对聚氨酸性能有影响。     

二苯甲烷二异氰酸酯的绿色催化合成

研究了二苯甲烷二氨基甲酸甲酯（MDC）催化热分解生成二苯甲烷二异氰酸酯（MDI）的工艺过程。结果表明：在真空度保持O．097MPa下,适宜的反应温度为250℃,催化剂用量占MDC用量的6％,此条件下热分解约40min,二苯甲烷二氨基甲酸甲酯（MDC）的转化率可达到99．8％,二苯甲烷二异氰酸醣（MDI）的收率为70．3％。     

浅谈二苯基甲烷二异氰酸酯的合成方法

介绍了二苯基甲烷二异氰酸酯的主要合成方法,比较了光气化法和非光气化法的各自优缺点。光气化法工业化技术成熟,但原料剧毒,存在潜在的安全隐患,设备投资大,目前工业化生产仍多采用该法;非光气化法又分为一步法、二步法和三步法,反应条件苛刻,但前景广阔。