硅烧改性聚氨酯密封胶的研究进展

以硅烷作偶联剂,以硅氧基湿气固化代替异氰酸酯基湿气固化合成硅烷改性聚氨酯(SPU)预聚体,再加入硅烷粘接促进剂、硅烷干燥剂和其他成分制备性能优良的密封胶.异氰酸酯、多元醇、硅烷等原材料的选择以及异氰酸酯基与羟基的配比是影响SPU密封胶性能的主要因素.目前的研究重点是开发硅烷新产品并用于制备高性能的改性PU密封胶,扩大已有硅烷改性PU密封胶的应用领域.     

单组份聚氨酯弹性密封胶的研究

本文是单组份湿固化聚醚型聚酯密封胶的合成与研究。该胶由二官能度和三官能度聚醚与ＴＤＩ反应制成预聚体后再加入多种填料和催化剂制成。讨论了ＴＤＩ用量,反应温度,聚醚的组成及填料对该胶的影响。     

增塑剂对硅烷化聚氨酯密封胶性能的影响

以自制的硅烷化聚氨酯预聚物为主要原料,配合补强填料、增量填料、固化催化剂等配制成湿固化硅烷化聚氨酯(SPU)密封胶。通过溶胀实验和动态力学性能分析,讨论了增塑剂对SPU密封胶的溶胀性能、增塑效率以及力学性能的影响。结果表明,氯化石蜡-52、白油和液体石蜡三种增塑剂中,以氯化石蜡-52与SPU的相容性最好、增塑效率最高;当氯化石蜡-52用量为10份时,密封胶拉伸强度为1.65 MPa、断裂伸长率为335%、邵A硬度为37。     

照明用高强度有机硅密封胶的研究

以烷氧基聚二甲基硅氧烷(封端107硅橡胶)为原料,气相白炭黑和纳米碳酸钙等为补强填料,甲基三甲氧基硅烷及聚甲基三甲氧基硅烷混合物为交联剂,采用双乙酰乙酸乙酯钛酸二异丙酯螯合物催化剂,氨基环氧基硅烷回流物为粘附促进剂,制备高强度有机硅密封胶。研究了封端107胶黏度、补强填料用量、混合交联剂用量、催化剂用量对高强度有机硅密封胶性能的影响。结果表明,采用黏度为1500 mPa·s封端107硅橡胶100份,白炭黑35份,碳酸钙100份,交联剂3份,催化剂2份,粘附促进剂0.8份,制得的密封胶综合性能最佳,具有最大的拉伸强度和剥离强度。     

高强度硅烷化聚氨酯(SPU)密封胶的研究

综述了硅烷化聚氨酯(SPU)密封胶的性能优势和特点,研究硅烷化聚氨酯、填料和黏附促进剂三者对高强度硅烷化聚氨酯密封胶性能的影响。结果表明:中模量的SPUR1、SPUR2树脂和高模量的SPUR3以1∶6的质量比例进行复配使用时,密封胶的强度和断裂伸长率都能满足应用要求;偶联剂A-1100和A-1120进行等量混合使用后,密封胶的固化速率和力学性能都能取得相对较佳效果;在纳米碳酸钙用量占总配方量的50%~60%时,密封胶的补强性及工艺操作性取得最佳平衡。最后介绍了高强度硅烷化聚氨酯密封胶的应用前景。     

硅烷封端羟基硅油改性端硅氧烷聚氨酯密封胶的研究

用2,4-甲苯二异氰酸酯(TDI)、α,ω-二羟基聚二甲基硅氧烷、聚醚多元醇和硅烷偶联剂为原料,分别制备了硅烷封端的羟基硅油(SHS)和端硅氧烷聚氨酯(SPU),并将其共混制备出硅烷封端羟基硅油改性的SPU密封胶。用红外光谱对预聚体进行了表征,考察了密封胶的力学性能。结果表明,添加的硅烷封端羟基硅油与SPU的质量比为50∶100时,SPU密封胶在保持高拉伸强度的同时,断裂伸长率比未添加硅烷封端羟基硅油的密封胶提高了46.7%。通过改变硅烷偶联剂的种类、填料和催化剂的种类和添加量,找到了偶联剂、填料和催化剂对硅烷封端羟基硅油改性SPU密封胶力学性能的影响规律。     

蒙脱土与有机硅共改性聚氨酯型密封胶的研究

采用2,4-甲苯二异氰酸酯(TDI)、聚醚多元醇、纳米有机蒙脱土(OMMT)、α,ω-二羟基聚二甲基硅氧烷和硅烷偶联剂为原料,制备了蒙脱土和有机硅复合改性的硅烷化聚氨酯(SPU)密封胶。研究了有机硅和OMMT用量、填料、催化剂的种类及用量对SPU密封胶力学性能的影响。采用X射线衍射和红外光谱对预聚体进行了表征,研究表明,经有机化处理的蒙脱土和有机硅复合改性的SPU密封胶具有性能互补效果,能同时提高密封胶的拉伸强度和伸长率。比纯SPU密封胶分别提高了72.5%和73.2%。     

门窗用硅烷封端聚氨酯密封胶

广东新展化工新材料有限公司的方铭中等人以硅烷封端聚氨酯预聚物、邻苯二甲酸二异壬酯、纳米碳酸钙、聚酰胺SL、气相法白炭黑R812S、二月桂酸二丁基锡、乙烯基三甲氧基硅烷、N-β-氨乙基-γ-氨丙基三甲氧基硅烷、γ-氨丙基三甲氧基硅烷为原料,制成了门窗用硅烷封端聚氨酯密封胶（SPU）。研究了补强剂纳米碳酸钙的种类、用量以及触变剂的种类对SPU密封胶性能的影响。     

硅烷封端聚氨酯密封胶研究进展

介绍了硅烷封端聚氨酯(SPU)密封胶的特点及合成方法,阐述了多元醇、异氰酸酯、异氰酸酯基与羟基物质的量比、硅烷封端剂以及其他助剂对SPU密封胶性能的影响,总结了SPU密封胶在建筑、汽车工业等领域的应用,最后对SPU密封胶的发展方向提出了建议。     

单组分湿固化硅烷封端聚氨酯密封胶的制备及性能研究

以硅烷封端聚氨酯预聚物为基础聚合物,制备了单组分湿固化硅烷封端聚氨酯密封胶,考察了配方中填料及助剂对密封胶表干时间、力学性能的影响,研究了该密封胶储存稳定性的改善问题。结果表明：催化剂二月桂酸二丁基锡用量达0．3份时,表干时间的缩短趋于平缓,配方组分中不加黏附促进剂KH-792时,密封胶的表干时间较长;炭黑用量达到40份时,该密封胶固化后的拉伸强度达6MPa以上;KH-792的加入将增大密封胶体系的交联密度,使其伸长率下降;吸水剂A-171及硅灰石的加入可有效提高单组分湿固化硅烷封端聚氨酯密封胶的储存稳定性。     

Room Temperature Curing Epoxy Adhesives for Elevated Temperature Service,Part II: Composition,Properties, Microstructure Relationships

Low temperature curing epoxy formulations for elevated temperature service have been previously developed and studied (Part I¹). Balanced performance with respect to shear and peel properties have been obtained for a system composed of a tetra and trifunctional epoxy blend crosslinked by a mixture of multifunctional amine and an amino-terminated elastomer. In continuation of the previous study, the present one is aimed at investigation the effect of substitution of difunctional epoxy resin and curing agent for trifunctional ones on the developing microstructure and resulting mechanical properties. Furthermore, a new type of amino-terminated-acrylonitrile (ATBN) and an epoxy-terminated silane were included in the present investigation. Experimental results show that while reduction in the overall functionality of the reactants results in a lower lap shear strength, it gives rise to enhancement in peel strength. The same effect was observed when the new ATBN was used. Thermal analysis of the polymerization processes, taking place during curing of the various low temperature curing formulations, indicates that the curing activation energies are appreciably lower compared with high temperature curing systems. Addition of silane, ATBN and substitution of the multifunctional amine curing agent by a lower functional one, resulted in a moderate increase in the activation energy. The basic formulation, comprising a tetra- and trifunctional resin blend and a multifunctional amine and ATBN crosslinking mixture, developed a typical two-phase matrix-rubber microstructure. A third phase was observed when the trifunctional epoxy resin or the multifunctional curing agent was substituted by lower functional ones. A similar three-phase morphology was obtained when the epoxy-terminated silane was added to the basic treta- and trifunctional reactant system.     

Room Temperature Curing Epoxy Adhesives for Elevated Temperature Service, Part II: Composition, Properties, Microstructure Relationships

Low temperature curing epoxy formulations for elevated temperature service have been previously developed and studied (Part I¹). Balanced performance with respect to shear and peel properties have been obtained for a system composed of a tetra and trifunctional epoxy blend crosslinked by a mixture of multifunctional amine and an amino-terminated elastomer. In continuation of the previous study, the present one is aimed at investigation the effect of substitution of difunctional epoxy resin and curing agent for trifunctional ones on the developing microstructure and resulting mechanical properties. Furthermore, a new type of amino-terminated-acrylonitrile (ATBN) and an epoxy-terminated silane were included in the present investigation. Experimental results show that while reduction in the overall functionality of the reactants results in a lower lap shear strength, it gives rise to enhancement in peel strength. The same effect was observed when the new ATBN was used. Thermal analysis of the polymerization processes, taking place during curing of the various low temperature curing formulations, indicates that the curing activation energies are appreciably lower compared with high temperature curing systems. Addition of silane, ATBN and substitution of the multifunctional amine curing agent by a lower functional one, resulted in a moderate increase in the activation energy. The basic formulation, comprising a tetra- and trifunctional resin blend and a multifunctional amine and ATBN crosslinking mixture, developed a typical two-phase matrix-rubber microstructure. A third phase was observed when the trifunctional epoxy resin or the multifunctional curing agent was substituted by lower functional ones. A similar three-phase morphology was obtained when the epoxy-terminated silane was added to the basic treta- and trifunctional reactant system.     

Study of Properties of One-Component Moisture-Curable Polyurethane and Silane Modified Polyurethane Adhesives

Abstract

In this paper, the curing behavior and adhesion properties of five kinds of polyurethane (PU) and silane modified polyurethane (SPU) adhesives were studied. Fourier transform infrared spectra showed that the adhesive Sikaflex-555 had an SPU structure and that the other four adhesives were one-component polyurethanes. The experimental results of curing behavior show that the tack-free times and curing rates of these adhesives were significantly affected by the relative humidity and the temperature. The adhesion of the SPU adhesive to glass sheet, zinc galvanized steel sheet and steel sheet was much better than that of PU adhesives. The tack-free times and curing rates of all the adhesives was measured during the 12 months of storage.     

紫外光固化玻璃涂膜附着力的研究

研究了低聚物、活性稀释单体以及助剂对玻璃涂膜附着力的影响。实验发现加入一定量的三官能团酸酯或硅烷偶联剂可以显著提高紫外光固化玻璃涂膜对玻璃的附着力。     

Syntheses of epoxy‐bridged polyorganosiloxanes and the effects of terminated alkoxysilanes on cured thermal properties

A series of epoxy‐bridged polyorganosiloxanes have been synthesized by reacting multifunctional aminoalkoxysilanes with diglycidyl ether of bisphenol A (DGEBA) epoxy resin. The reactions of trifunctional 3‐aminopropyltriethoxysilane (APTES), difunctional 3‐aminopropylmethyldiethoxysilane (APMDS), and monofunctional 3‐aminopropyldimethylethoxysilane (APDES) with DGEBA epoxy have been monitored and characterized by FTIR, ¹H NMR, and ²⁹Si NMR spectra in this study. The synthesized epoxy‐bridged polyorganosiloxanes precursors, with different terminated alkoxysilane groups, are thermally cured with or without the addition of curing catalysts. Organometallic dibutyltindilaurate, and alkaline tetrabutylammonium hydroxide have been used as curing catalysts to investigate the thermal curing behaviors and cured properties of epoxy‐bridged polyorganosiloxanes precursors. The maximum exothermal curing temperatures of epoxy‐bridged polyorganosiloxanes precursors are found to appear around the same region of 120°C in DSC analysis. The addition of catalysts to the epoxy/APTES precursor shows significant influence on the cured structure; however, the catalysts exhibit less influence on the cured structure of epoxy‐APMDS precursor and epoxy/APDES precursor. Curing catalysts also show significant enhancement in increasing the thermal decomposition temperature (T_d50s) of cured network of trifunctional epoxy‐bridged polyorganosiloxane (epoxy/APTES). High T_d50s of 518.8 and 613.6 in the cured hybrids of epoxy/APTES and epoxy/APMDS precursors are also observed, respectively. When trialkoxysilane‐terminated epoxy‐bridged polyorganosiloxanes precursor are cured, with or without the addition of catalyst, no obvious T_g transition can be found in the TMA analysis of cured network. The cured network of trialkoxysilane‐terminated epoxy‐bridged polyorganosiloxanes also exhibits the lowest coefficient of thermal expansion (CTE) among the three kinds of alkoxysilane‐terminated epoxy‐bridged polyorganosiloxanes investigated. The organic–inorganic hybrid, from epoxy‐bridged polyorganosiloxanes after the thermal curing process, shows better thermal stability than the cured resin network of pure epoxy‐diaminopropane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3491–3499, 2006     

Effect of monofunctional and trifunctional modifiers on a phase mixed polyurethane system

The dynamic mechanical behavior of a phase mixed polyurethane system modified with trifunctional and monofunctional alcohols was investigated and compared with a typical polyurethane system with a difunctional alcohol. Of interest was verifying that the average functionality of the alcohol would determine the dynamic mechanical properties and not whether that functionality was achieved by an equimolar blend of trifunctional and monofunctional alcohols or by a purely difunctional alcohol. The base system consisted of poly(tetramethylene ether)glycol (PTMG) cured with 4,4′-diphenylmethane diisocyanate (MDI). The trifunctional alcohol was trimethylol propane (TMP). The monofunctional alcohol was decyl alcohol (DA). Samples with a typical difunctional alcohol, 2,2-dimethyl-1,3-propanediol (DMPD), were prepared and their properties compared with those of the above samples. To a first approximation, the properties of TMP-DA modified polymers are identical to those of DMPD polymers of the same hard segment concentration. These results confirm our hypothesis that the dynamic properties obtained from a combination of a trifunctional alcohol with a monofunctional alcohol are essentially equivalent to those of a difunctional alcohol.     

紫外光固化卷材涂料的研制

紫外光固化涂料由于固化速度快、体积收缩大,故通常存在与金属基材附着力差的问题。以多官能脂肪族聚氨酯丙烯酸酯和双酚A环氧丙烯酸酯作为预聚物、甲基丙烯酸羟乙酯作为活性单体、磷酸酯作为附着力促进剂,研究了涂料体系各组分配比及固化时间对涂膜性能的影响。     

3-羟乙基-1,3-噁唑烷的合成和表征及其初步应用

以甲醛和二乙醇胺为原料,采用加成缩合反应合成了化合物3-羟乙基-1,3-噁唑烷。毛细管气相色谱(GC)研究表明可通过减压蒸馏提纯产物。采用傅里叶变换红外光谱(FT-IR)、13C核磁共振谱(13CNMR)对产物的结构进行了表征。将所合成的3-羟乙基-1,3-噁唑烷用作单组分湿固化聚氨酯体系的潜固化剂,抑泡效果明显,固化后样品的伸长率提高了10倍以上。