陶瓷前驱体聚硅氮烷的制备研究进展

综述了合成Si-C-N陶瓷前体聚硅氮烷的一些方法,着重介绍了含金属聚硅氮烷的制备方法,如:含钛聚硅氮烷、铝基聚硅氮烷、铁基聚硅氮烷、锆基聚硅氮烷、硼基聚硅氮烷、钇基聚硅氮烷、铜基聚硅氮烷的制备方法;其次介绍了使用共聚法、超支化法、倍半硅氮烷水解法制备聚硅氮烷的方法。     

聚硅氮烷的应用研究进展

在简要介绍聚硅氮烷发展历程的基础上,综述了聚硅氮烷的应用研究进展,主要包括纤维、涂层、块体、多孔陶瓷、微电子机械系统(MEMS)等应用形式,并结合本课题组在聚硅氮烷方面的研究成果展望了聚硅氮烷的发展前景。     

硅氮烷对高强度硅橡胶性能的影响

本文介绍了在制备高强度硅橡胶过程中,利用硅氮烷作为加工助剂时的良好效果。不但具有比二苯基硅二醇更高的抗结构化能力,而且还能获得较高抗张强度和抗撕强度的硫化胶。 共试验了下列数种硅氮烷:六甲基环三硅氮烷(D_3~N)、八甲基环四硅氮烷(D_4~N)、六苯基环三硅氮烷(Ph_2D_3~N)、三甲基三苯基环三硅氮烷〔(PhCH_3SiNH)_3〕、甲基线型硅氮烷以及各种高沸物等,对加工工艺而言,以含甲基者为最佳;对耐热性而言,以含二苯基者较好,当使用比表面较大的气相二氧化硅(如沈阳化工厂产的4~#白炭黑)为补强剂时,以二苯基硅二醇为抗结构化试剂,效果就很差,改用硅氮烷则加工非常顺利。用同一种补强剂(如沈阳化工厂产的2~#白炭黑),用二苯基硅二醇和硅氮烷分别作为加工助剂进行比较,使用前者所得硫化胶强度颇低,使用后者其强度显著提高。 对于硅氮烷和气相二氧化硅的作用,通过红外光谱的检查,发现当二氧化硅未与硅氮烷接触之前,各种硅醇基的特征峰明显地存在。一旦用硅氮烷处理后,大部份羟基消失,同时增加了二甲硅基〔(CH_3)_2Si〕的特征峰,这充分说明了硅氮烷与硅醇基发生了反应。由于在二氧化硅表面上取代了二甲硅基,这就使填料与有机硅生胶大大地增加了相容性,从而使填料分散的比较均匀,有利于提高强度。     

Si-C-N陶瓷前驱体聚硅氮烷合成的研究进展

综述了合成Si—C—N陶瓷前驱体聚硅氮烷的主要方法，即氨／Q解氯硅烷法、硅氮烷低聚物交联法、硅氮烷低聚物与氯硅烷反应法及氯硅氯烷和氯硅烷脱氯编聚法，并介绍了用铝、硼、钛、钇等元素对聚硅氮烷进行改性，以提高Si—C—N陶瓷性能的方法。     

含氟聚硅氮烷的制备及其性能研究

聚甲基氢硅氮烷(简称PMSZ)是一类典型的有机聚硅氮烷(OPSZ)。通过硅氢加成反应在PMSZ的硅氢键上引入全氟烯烃，合成了一种新型的氟代有机硅材料，该含氟聚硅氮烷具有优异的附着力和较低的表面能特性，可以将其作为功能涂料有效改善底材的防污易清洁特性。在此基础上，系统考察了含氟聚硅氮烷在硬度、抗开裂、耐磨等机械性能上的表现，阐明了不同含氟量聚硅氮烷对涂层性能的影响，很好地解决了以往有机硅和有机氟树脂在防污易清洁涂层构建上的缺陷。     

加成型有机硅模具胶的研制

以端乙烯基硅油和功能性助剂处理的气相法白炭黑的混炼物作为基料,含氢硅油作为交联剂,制得加成型有机硅模具胶.考察了气相法白炭黑、功能性助剂和含氢硅油对模具胶性能的影响.结果表明,气相法白炭黑选择QS-40,且其用量为32份,功能性助剂六甲基二硅氮烷、四甲基二乙烯基二硅氮烷、水质量比为5:1:3,含氢硅油选择氢封端氢甲基硅...     

前驱体法制备Si-C-N-M基高性能陶瓷的研究进展

综述了聚合物前驱体热解转化法制备高性能Si-C-N-M基陶瓷的研究进展，着重介绍了3类Si-C-N-B基陶瓷前驱体（主链或侧基含有环硼氮烷或含硼杂环的聚硼硅氮烷、含硼聚硅氮烷和含硼聚硅基碳化二亚胺）及Si-C-N-Al基陶瓷前驱体。     

聚硅氮烷的制备及其在涂料中的应用实例

简述了聚硅氮烷的制备方法及其在涂料中的应用实例,指出聚硅氮烷在涂料工业中的应用必将为涂料工业新材料和新产品增色生辉。     

SiAlCN型PDC陶瓷的研究进展

综述了SiAlCN型PDC（Polymer Derived Ceramics）陶瓷的制备、性能和应用。SiAlCN陶瓷有四类制备方法：粉末混合型：聚硅氮烷陶瓷前驱体与氧化铝粉末直接混合;粉末溶解型：含铝化合物粉末溶解于聚硅氮烷前驱体溶液中;单源前驱体型：铝原子通过适当的含铝化合物接枝在聚硅氮烷主链上,生成一种单源陶瓷前驱体聚铝硅氮烷;聚合物混合型：两种聚合物即聚硅氮烷与含铝聚合物共混;然后交联裂解制备陶瓷。与无Al的Si/C和Si/C/N体系相比,SiAlCN陶瓷具有优异的抗蠕变性、更好的抗氧化性和耐腐蚀性以及更好的导热性。因此,聚合物衍生的硅铝碳氮化物(SiAlCN)陶瓷是在高温和恶劣环境中应用很有潜力的材料。     

聚硼硅氮烷固化氰酸酯基耐高温胶粘剂的制备与性能研究

以氰酸酯为基胶,聚硼硅氮烷前驱体为固化剂,复配相应的填料,制备了氰酸酯基耐高温胶粘剂。研究了聚硼硅氮烷用量对氰酸酯固化特性、固化产物的结构变化及固化物热稳定性的影响。研究结果表明：与传统的氰酸酯胶粘剂相比,聚硼硅氮烷催化氰酸酯的固化温度降低了50～100℃;聚硼硅氮烷可以催化氰酸酯在150℃低温固化,20份聚硼硅氮烷催化氰酸酯固化物T_5%最高达到476.3℃。以此为基础制备的耐高温胶粘剂的室温粘接强度最高为16 MPa,400℃老化3 h后粘接强度仍达到12 MPa,表明该胶粘剂具有较好的粘接性能和耐老化性能。本研究制备的胶粘剂凭借较低的固化温度、良好的粘接性能和耐温性,有望用于航空、航天和电子等行业。     

Effect of polysiloxane additives on the scratch resistance of an acrylic melamine automotive clearcoat

Many attempts have been carried out to increase the scratch resistance of clearcoats using various appropriate additives. These additives may increase surface hardness or surface slippage, and/or enhance the bulk mechanical strength of the clearcoat. In the present study, the influence of various added loads of three differently structured polysiloxane additives on the scratch resistances of an acrylic melamine clearcoat was investigated. A series of analytical instruments, such as a laboratory carwash simulator, a scanning electron microscope, an optical microscope and an attenuated total reflectance Fourier transform infrared spectroscope, and others were used to compare the effects of the various added contents of polysiloxane additives on changes in the viscoelastic properties and scratch morphologies of the resultant clearcoats. The results illustrated that all polysiloxane additives improve the scratch resistance of such clearcoats, yet the optimum load varied for each individual additive. There is also a good indication that polyether-modified polysiloxanes improve scratch resistance by increasing surface hardness, while the fluorocarbon-modified polysiloxane tends to change the viscoelastic properties of the clearcoats. It was also found that scratch resistance varied linearly with Micro-Vickers’ hardness for brittle clearcoats.     

Studying the role of polysiloxane additives and nano-SiO2 on the mechanical properties of a typical acrylic/melamine clearcoat

Effects of conventional polysiloxane additives and nano-SiO₂ on the mechanical properties of an automotive acrylic/melamine clearcoat (CC) are studied. Clearcoats formulations were prepared by addition of different concentrations of polysioloxane additives (with different modifications) and hydrophobic nano-SiO₂ particles. Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) and atomic force microscope (AFM) were utilized to evaluate the effects of nano-SiO₂ and polysiloxane additives on the surface properties of the CCs. The mechanical properties of the surface and the bulk of the CCs were studied by nano-indentation and tensile tests, respectively. Results showed that polysiloxane additives can mostly affect the mechanical properties of the surface of the CC. Additives with shorter side chains and therefore higher surface activity caused higher changes on the surface properties the CC. Unlike conventional polysiloxane additives, the nano-SiO₂ particles mainly influenced the mechanical properties of the bulk of the CC.     

Studying the role of polysiloxane additives and nano-SiO2 on the mechanical properties of a typical acrylic/melamine clearcoat

Effects of conventional polysiloxane additives and nano-SiO₂ on the mechanical properties of an automotive acrylic/melamine clearcoat (CC) are studied. Clearcoats formulations were prepared by addition of different concentrations of polysioloxane additives (with different modifications) and hydrophobic nano-SiO₂ particles. Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) and atomic force microscope (AFM) were utilized to evaluate the effects of nano-SiO₂ and polysiloxane additives on the surface properties of the CCs. The mechanical properties of the surface and the bulk of the CCs were studied by nano-indentation and tensile tests, respectively. Results showed that polysiloxane additives can mostly affect the mechanical properties of the surface of the CC. Additives with shorter side chains and therefore higher surface activity caused higher changes on the surface properties the CC. Unlike conventional polysiloxane additives, the nano-SiO₂ particles mainly influenced the mechanical properties of the bulk of the CC.     

Novel, water-based fluorinated polymers with excellent antigraffiti properties

In this article we describe novel, water-based, crosslinkable fluorinated polymers that form coatings with excellent antigraffiti properties. The synthesis of the binders and the surface and bulk properties of their coatings are discussed. The surface properties of these coatings are characterized in terms of their surface-free energy, as calculated from static contact angle measurements. The distribution of the fluorine atoms throughout the coating is measured by X-ray photoelectron spectroscopy (XPS). The bulk properties are studied by determining the crosslink density through dynamic mechanical thermal analysis (DMTA), and the effect of the crosslinking conditions on the crosslink density and the antigraffiti properties is discussed. The results indicate that a combined action of surface and bulk properties gives these coatings their excellent antigraffiti properties. The applicability of these polymers as protective coatings for metal and concrete surfaces are demonstrated. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL     

Studying the rheology,optical clarity and surface tension of an acrylic/melamine automotive clearcoat loaded with different additives

Acrylic/melamine based automotive clearcoats were prepared by inclusion of functional and conventional additives. The conventional additives used were based on polysiloxane chains without any reactive groups. On the other hand, the functional additives were based on polyacrylate and polysiloxane backbones. The additives were added to the clearcoat formulations at different concentrations. Surface tension, optical properties and rheological behaviors of the clearcoats were studied by tensiometer, gonio-spectrophotometer, rheometric mechanical spectrometer (RMS) and Brookfield techniques. Results showed that addition of both conventional and functional additives reduced the surface tension of the clearcoat up to a certain value of the additive concentration. It was seen that functional additives could reduce surface tension much greater than the conventional ones. The coating clarity and transparency were not affected in presence of conventional additives. However, the functional additives, especially the one having higher molecular weight, reduced the coating transparency. The clearcoat viscosity was increased using functional additives. A shear thickening behavior of the clearcoats loaded with functional additives was seen. The conventional additives did not change the clearcoat viscosity. It was concluded that the additive functionality, molecular weight and chemical structure were influential parameters affecting the final properties.     

Investigating the antigraffiti properties of a polyurethane clearcoat containing a silicone polyacrylate additive

In this study, a polyurethane clearcoat was modified using a silicone polyacrylate antigraffiti additive and its surface free energy and mechanical properties were evaluated by various analytical techniques. The results showed that surface free energy decreased by replacing the polyol resin with the additive up to 10 mol%. Dynamic mechanical thermal analysis (DMTA) showed that the presence of the additive increased the storage modulus of the samples at ambient temperature. Evaluation of stainability of the coatings containing the additive revealed that a spray paint would be repelled from the surface showing a proper antigraffiti behavior. The additive did not affect the surface roughness of the films, indicating that the antigraffiti properties resulted from changes in surface chemistry due to migration of the additive to the surface.     

A new approach to investigate scratch morphology and appearance of an automotive coating containing nano-SiO2 and polysiloxane additives

Attempts have been carried out to verify whether gonio-spectrophotometry could be utilized as a new scratch testing approach to investigate scratch morphology and its effect on appearance of an acrylic-melamine clearcoat separately containing nano-silica or polysiloxane additives. The results of gonio-spectrophotometry/colorimetry illustrated that this new approach is capable of differentiating between plastic and fracture types scratches. Furthermore, this approach was found to be suitable for analyzing the self healing abilities of such coatings. The accuracy and reproducibility of such results were checked against the results of scanning electron microscope (SEM) and illustrated great potential as a new approach for such studies.     

低表面能UV固化水性柔感塑料涂料的研究

将季戊四醇三丙烯酸酯（PETA）和聚二甲基硅氧烷（PDMS）引入水性聚氨酯的主链,制得硅氧烷改性的UV固化水性聚氨酯乳液,通过FTIR红外光谱对乳液的结构进行表征。将该乳液与助剂复配,制得水性塑料涂料,并对涂层的固化动力学和表面性能进行研究。与未改性的涂料相比,硅氧烷改性的UV固化水性涂料具有良好的耐水性和耐溶剂性,同时保留了优良的手感,可用作水性柔感塑料涂料。     

耐高温硅酮油墨的研制

以聚硅氧烷为主体材料，配以钛白粉和其它助剂制成硅酮油墨，并研究了增粘剂添加量、催化剂用量对其耐冷热冲击性、耐热性、耐溶剂性的影响     

双官能基改性聚有机硅氧烷的合成及应用研究进展

介绍了氨基和聚醚改性聚硅氧烷、氨基和酰氨基改性聚硅氧烷、氨基和长链烷烃改性聚硅氧烷、环氧基和聚醚改性聚硅氧烷及羧基和长链烷烃改性聚硅氧烷等双官能基改性聚有机硅氧烷的特性，简述了合成过程及应用工艺，并对其前景进行了预测。