无溶剂法合成高固含量水性聚氨酯

以混合二异氰酸酯[六亚甲基二异氰酸酯(HDI)/异佛尔酮二异氰酸酯(IPDI)]和聚己二酸丁二醇酯(PBA-2000)为基本原料、二羟甲基丁酸(DMBA)为亲水性单体[代替目前常用的二羟甲基丙酸(DMPA)]、三乙胺(TEA)为中和剂和乙二胺(EDA)为扩链剂,反应过程中不添加有机溶剂和催化剂,采用先乳化后扩链的预聚体分散法制备了固含量为50%左右的水性聚氨酯(WPU)。采用单因素试验法优选出制备WPU乳液的较佳工艺条件。结果表明:当R=n(-NCO)∶n(-OH)=1.88∶1、w(DMBA)=4.1%和n(EDA)∶n(-NCO)=0.37∶1时,WPU胶膜的强度(拉伸强度为23 MPa)和韧性(断裂伸长率为740%)俱佳。     

高固含量水性聚氨酯的研究进展

从乳化工艺、亲水单体、异氰酸酯指数(R值)和软段等方面综述了水性聚氨酯(WPU)固含量的影响因素,并对高固含量WPU的发展趋势进行了展望。     

高固含量聚醚型水性聚氨酯的合成与影响因素

以异佛尔酮二异氰酸酯(IPDI)和六次甲基二异氰酸酯(HDI)为硬段、聚醚(N-220)为软段,二羟甲基丙酸(DMPA)为亲水性物质、乙二胺为后扩链剂和三羟甲基丙烷(TMP)为交联剂等,合成了高固含量的聚醚型水性聚氨酯(WPU)乳液。采用衰减全反射红外光谱(ATR)对其结构进行了表征,并探讨了溶剂(丙酮)和DMPA含量、反应过程中预聚体的黏稠度、扩链剂的加料顺序和扩链时间等因素对WPU乳液固含量的影响。实验结果表明,在保持其他条件不变的情况下,即n(-NCO)∶n(-OH)=1.2∶1、m(HDI)∶m(IPDI)=2∶1和n(TMP中-OH)∶n(聚醚中-OH)=1∶4、w(DMPA)=1.5%(相对于树脂而言)且w(丙酮)=50.4%～75.5%(相对于树脂而言)时,在预聚反应过程中,若体系较稀(即黏度较低),在乳化时先加入乙二胺,待反应4～7min后再加入水,如此易制得稳定的高固含量(40%～46%)聚醚型WPU乳液。     

高固含量鞋用水性聚氨酯胶粘剂的合成

以HDII、PDI和聚己二酸-1,4-丁二醇酯为基本原料,二氨基苯磺酸钠(SDBS)和二羟甲基丙酸为内乳化剂,通过丙酮法制备出高固含量(50%以上)、不含有机溶剂和储存稳定的鞋用水性聚氨酯胶粘剂。经红外光谱分析,证实其含有磺酸基团。研究了SDBS和丙酮用量对胶粘剂性能的影响,实验结果表明,其性能达到或超过市售U-54产品。     

高固含量羧酸/磺酸盐型水性聚氨酯乳液的合成

以聚己二酸-1,4-丁二醇酯(PBA)和异佛尔酮二异氰酸酯(IPDI)为原料,以乙二胺基乙磺酸钠(AAS)和二羟甲基丙酸(DMPA)为亲水扩链剂制备了高固含量羧酸/磺酸盐型水性聚氨酯乳液。聚氨酯薄膜经红外光谱分析证实聚氨酯分子中含有磺酸基团。系统研究了—NCO/—OH物质的量比(R值)、DMPA含量和AAS含量对乳液及胶膜性能的影响。研究结果表明:当R值为1.6、DMPA含量为0.8%～1.0%、AAS含量为3.5%时,获得的乳液和胶膜的综合性能最佳。     

高固含量环氧改性磺酸盐型水性聚氨酯的合成与表征

以异氟尔酮二异氰酸酯(IPDI)、六亚甲基二异氰酸酯(HDI)、聚己二酸-1,4-丁二醇酯(PBA)为主要原料,以1,4-丁二醇为小分子扩链剂,以乙二胺基乙磺酸钠为亲水性扩链剂,并用环氧树脂E-51作为改性剂,得到固含量为50%的环氧树脂改性磺酸盐型水性聚氨酯乳液SWPU-E。实验研究了环氧用量对乳液的粒径及其分布和对胶膜力学性能的影响;实验还采用红外、核磁、热重分析等方法对胶膜的结构和热稳定性等进行了深入的分析。结果表明:环氧树脂的羟基和环氧基团参与了反应,生成了环氧改性的水性聚氨酯结构;随着环氧用量的增加,乳液的平均粒径从95.8 nm增加到169 nm,粒径分布变宽;胶膜的拉伸强度随之变大,当环氧用量低于4%时,拉伸强度明显增加,由16.21 MPa增加到43.7 MPa,之后拉伸强度增加缓慢;胶膜的热稳定性随环氧用量的增加得到明显提高,初始分解温度、转折点温度、分解终点温度均朝高温方向移动。     

高固含量阳离子水性聚氨酯的性能研究

以聚酯二元醇为软段、异佛尔酮二异氰酸酯(IPDI)和N-甲基二乙醇胺(N-MDEA)为主要原料,采用丙酮法合成了高固含量(约50%)的CWPU(阳离子水性聚氨酯),并着重探讨了N-MDEA含量、软段种类对该CWPU的基本性能、结晶性能、力学性能和粘接性能等影响。结果表明:当w(N-MDEA)=5.5%～7.0%(相对于预聚体质量而言)时,可制得稳定的高固含量CWPU;软段的结晶性越好,高固含量CWPU的力学性能和粘接性能越高;当软段为聚己二酸己二醇酯(PHA)时,相应高固含量CWPU的邵A硬度(84)、拉伸强度(55 MPa)和剥离强度(初始剥离强度、24 h剥离强度为68.2、90.4 N/25 mm)相对最大,可作为胶粘剂使用。     

高固含量水性聚氨酯的合成及其主要影响因素

以异佛尔酮二异氰酸酯(IPDI)和六亚甲基二异氰酸酯(HDI)为硬段,聚醚二元醇(N-220)及聚酯二元醇(PBA)为软段,二羟甲基丙酸(DMPA)为亲水性物质,乙二胺(EDA)为后扩链剂等,合成了固含量约为50%的环氧树脂(E-20)及甲基丙烯酸甲酯(MMA)复合改性的水性聚氨酯分散体(PUD).并探讨了-NCO/-OH物质的量比、软段类型和软段相对分子质量对高固含量水性聚氨酯性能的影响,同时对制得的PUD进行红外、透射电镜等测试分析,从而制备出性能较好、较稳定的高固含量水性聚氨酯分散体.     

高固含量聚氨酯的合成及应用研究进展

综述了国内外高固含量PU(聚氨酯)的合成进展及应用,重点介绍了溶剂型PU和WPU(水性聚氨酯)及其影响因素[如原料、扩链剂、溶剂、R值或R=n(-NCO)/n(-OH)等],并展望了未来PU材料的发展方向。     

高固含量水性聚氨酯的合成及工艺研究

以异佛尔酮二异氰酸酯(IPDI)、聚己二酸乙二醇酯(721)、聚四氢呋喃二醇(PTHF)为基本原料,以2,2-二羟甲基丙酸(DMPA)和磺酸盐(HSJ)为亲水扩链剂,采用自乳化和外乳化相结合的方法合成阴离子型高固含水性聚氨酯乳液;考察了R值、聚酯/聚醚(—OH物质的量)比、DMPA、磺酸扩链剂和外乳化剂用量对乳液性能的影响。结果表明:R值为1.4,聚酯/聚醚(—OH物质的量)比为2:1,DMPA用量为1.6%,磺酸扩链剂为0.25%,外乳化剂用量为1.6%时,合成的乳液固含量可高达55%,黏度低,力学性能优异。     

高固含量水性聚氨酯合成的研究进展

介绍了水性聚氨酯(WpU)在提高固含量方面的研究现状;探讨了原料、R值、扩链剂、溶剂、中和方式等对WPU固含量的影响。展望了高固含量WPU的未来发展趋势。     

一种高固含量阴非离子水性聚氨酯的制备与性能研究

在聚氨酯(PU)链段中同时引入阴离子亲水单体和侧链为非离子的双羟基亲水单体(A-100),可以合成出一种稳定的高固含量阴非离子型水性聚氨酯(WPU)。讨论了软段种类、A-100用量等对WPU乳液的固含量及WPU胶膜性能的影响。结果表明:以聚碳酸酯二元醇(PCD)为软段,并引入适量的A-100,可以明显提高WPU乳液的固含量;当w(A-100)=4.2%时,WPU胶膜的综合性能最好;与聚环氧丙烷二元醇(PE220)相比,由PCD和A-100制备而成的WPU,其固含量较高(为57%)、综合性能较好。     

硅烷偶联剂改性高固含量水性聚氨酯的合成

以聚四氢呋喃二醇、聚己二酸乙二酯和异佛尔酮二异氰酸酯等为主要原料,以硅烷偶联剂KH550为改性剂,2,2-二羟甲基丙酸(DMPA)和(1,3-二氨基)-丁基磺酸钠(HSJ)为亲水扩链剂,采用自乳化和外乳化相结合的方法合成阴离子型高固含量硅烷偶联剂改性水性聚氨酯(WPU)乳液。考察了乳化剂、扩链剂、硅烷偶联剂用量,异氰酸酯基与羟基摩尔比(R值)等对乳液和胶膜性能的影响。通过傅里叶变换红外光谱、热重分析和接触角测试分析了改性前后WPU的结构。结果表明:DMPA,HSJ,乳化剂,硅烷偶联剂的质量分别占总固体质量的1.60%,0.26%,1.60%,1.50%,R值为1.20时,可得到固含量54%、黏度低、稳定性好、耐水、耐热性能优异的WPU乳液。     

Preparation and characterization of high solid content cationic waterborne polyurethane with core-shell structures

In this study, core-shell structured cationic waterborne polyurethane (WPU) dispersions with high solid content were prepared. To this end, prepolymer A was synthesized from polytetramethylene ether glycol (PTMG), isophorone diisocyanate (IPDI), castor oil (CO) and 1,4-butanediol (BDO) without integration of the hydrophilic groups. Prepolymer B with hydrophilic groups was prepared from PTMG, IPDI, CO, BDO and N-methyldiethanol amine (MDEA). WPU dispersion with a core-shell structure could be generated by mixing, neutralizing, and emulsifying of the prepolymer A and the prepolymer B. The results indicated that the generation of WPU dispersions through this technique exhibited a milky appearance while the pH values range from 5.30 to 5.60. The optimal combination of prepolymer A and prepolymer B (at a ratio of 5:5) resulted in a dispersion with the highest solid content (50.4%), lowest viscosity (69 mPa·s), and narrowest particle size distribution. As the proportion of prepolymer A to prepolymer B decreases, the tensile strength of WPU film reduces while the elongation at break and glass transition temperature increases. Moreover, initially the contact angle with water was decreased instead of increase. However, modifications in a ratio of prepolymer A and B was not showed any significant impact on the thermal stability performance of the WPU films.     

制备高固含量水性聚氨酯乳液的影响因素

以二异氰酸酯和聚酯二元醇合成聚氨酯预聚体,采用二羟甲基丙酸为亲水剂,制备了高固含量(总固物质量分数约50%)的水性聚氨酯(APU)乳液,研究了制备APU乳液的影响因素。结果表明:羧基质量分数为0.8%~1.3%、预聚体中NCO/OH(摩尔比)为1.5~1.9、助溶剂丙酮质量分数为5%左右,可制得高固含量APU乳液。选用结晶性较好的聚酯二元醇和碱性较强的中和剂有利于制备高固含量APU乳液。     

Synthesis and characterization of high solid content aqueous polyurethane dispersion

Aqueous polyurethane (APU) dispersions having a solid content of 50% were synthesized using dimethyol propionic acid (DMPA) as the stabilizing moiety. The principal diols used were poly‐1,4‐butylene adipate glycol (PBA). The diisocyanates used in this study were a 30:70 blend of hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). All these samples were neutralized using triethylamine (TEA) and chain‐extended using ethylene diamine (EDA). The effects of the COOH content, NCO/OH molar ratio, and molecular weight (M_n) of PBA on the properties of APU dispersion and its cast film were studied. Dynamic light scattering results revealed that these high solid content dispersions shown broad particle size distributions as well as bimodal. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMA) results showed that as the hard segment content increased, the melting point (T_m) of the APU cast film increased, but the glass transition temperature (T_g) did not show significant alteration, when a PBA lower than 1000 M_n was used, the APU exhibited faint soft‐segment crystallization and tended to form amorphous polymer. Tensile and T‐peel strength tests attained excellent mechanical properties, such as a maximum Young's modulus of 166 MPa and the elongation at break reached to 2000%. T‐peel strength test (PVC/PVC) yielded a maximum peel strength value of 8.8 N/mm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007