脂肪族水性聚氨酯的制备及性能研究

以异佛尔酮二异氰酸酯(IPDI)和聚醚二醇(PPG)为主要原料、二羟甲基丙酸(DMPA)为亲水扩链剂和乙二胺(EDA)为小分子扩链剂,采用预聚体分散法制备出一种水性聚氨酯(WPU)乳液。考察了n(-NCO)∶n(-OH)比例、EDA扩链方式等对WPU稳定性、玻璃化转变温度、力学性能和耐水性等影响。结果表明:将EDA先溶于水中,采用乳化与扩链同时进行的工艺,并且当n(-NCO)∶n(-OH)=1.5∶1时,WPU乳液稳定性好、粒径(14 nm)较小且分布较窄,WPU胶膜的力学性能(拉伸强度为3.683 MPa、断裂伸长率为347%)和耐水性(吸水率为19.7%)俱佳。     

高固含量双组分混合聚酯型水性聚氨酯的合成

以异佛尔酮二异氰酸酯(IPDI)为硬段、混合双组分聚酯二元醇和1,4-丁二醇(BDO)为软段、二羟甲基丙酸(DMPA)为亲水扩链剂、三乙胺(TEA)为中和剂和乙二胺(EDA)为后扩链剂等,采用预聚体分散法合成了系列高固含量的水性聚氨酯(WPU)乳液。以固含量、黏度和吸水率等为衡量指标,比较了不同聚酯二元醇的混合效果。结果表明:当混合聚酯中n(PBA或PCDL)∶n(PEBA或PCDL)=1∶1、w(DMPA)≈3.4%(相对于预聚体而言)、n(-NCO)∶n(-OH)=1.03∶1和中和度为96%时,由PBA2000/PCDL2000混合聚酯二元醇制取的WPU乳液,其固含量较高(48.70%)、黏度最低(542 mPa.s)且综合性能相对较好。     

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。     

DMPA含量对不同软段结构水性聚氨酯性能的影响

以聚酯多元醇、异佛尔酮二异氰酸酯(IPDI)和二羟甲基丙酸(DMPA)为主要原料,采用预聚体分散法合成了一系列具有不同软段结构的水性聚氨酯(WPU)。研究结果表明:随着DMPA掺量的不断增加,WPU的稳定性提高、黏度增大、粒径减小且粒径分布变窄,WPU胶膜的拉伸强度在一定范围内增大、断裂伸长率降低、水接触角减小和耐水性下降,并且软段微区的结晶性能降低。     

透明聚酯型水性聚氨酯的制备与性能研究

聚酯型WPU(水性聚氨酯)具有较高的力学强度和粘接强度,但是其较高的结晶性会导致胶膜透明性较差。以聚丙二醇(PPG)、聚己二酸丁二醇酯二醇(PBA)、异佛尔酮二异氰酸酯(IPDI)、2,2′-二羟甲基丙酸(DMPA)和1,4-丁二醇(BDO)等为原料,制备PPG改性聚酯型WPU。研究结果表明:PPG改性聚酯型WPU的黏度适中,储存稳定性良好;随着PPG含量的不断增加,WPU胶膜的透明性因结晶受阻程度增大而变好,相应胶粘剂的T型剥离强度和拉伸强度下降,而断裂伸长率升高;当w(PPG)=10%～20%时,相应WPU胶粘剂的透明性、T型剥离强度(≥1.97 N/mm)、拉伸强度(≥14.7 MPa)和断裂伸长率(≥421%)俱佳。     

IPDI/HDI型水性聚氨酯分散体的合成及性能研究

以脂肪族异氰酸酯[异佛尔酮二异氰酸酯(IPDI)、六次甲基二异氰酸酯(HDI)]、聚醚(N-220)为主要原料,通过丙酮法合成了水性聚氨酯(WPU)分散体。探讨了n(IPDI中-NCO):n(HDI中-NCO)比例、后扩链剂用量和交联度等对WPU胶膜力学性能和耐溶剂(水和乙醇)性能的影响。结果表明:随着n(IPDI中-NCO):n(HDI中-NCO)比例的增加,WPU胶膜的拉伸强度提高,断裂伸长率、耐水性和耐乙醇性均下降;当n(IPDI中-NCO):n(HDI中-NCO)=0.25:1时,WPU胶膜的吸水率只有6%;随着后扩链剂用量或交联度的增加,WPU胶膜的拉伸强度提高、断裂伸长率下降。     

硬段对聚碳酸酯二醇型水性聚氨酯性能的影响

以聚碳酸酯二醇(PCDL)为软段、二羟甲基丙酸(DMPA)为亲水扩链剂、异佛尔酮二异氰酸酯(IPDI)和六亚甲基二异氰酸酯(HDI)为硬段,采用预聚体法合成了水性聚氨酯(WPU)。研究结果表明:随着n(HDI)∶n(IPDI)比例的增加,WPU的黏度、断裂伸长率增大,耐水性和耐乙醇性提高;当n(HDI)∶n(IPDI)=1.0∶1时,WPU的综合性能相对较好,其热稳定性和结晶性能得到明显改善。     

油墨用水性聚氨酯乳液的制备及性能研究

以聚醚二元醇、甲苯二异氰酸酯(TDI)和二羟甲基丙酸(DMPA)为原料,制备了聚醚型芳香族水性聚氨酯(WPU)乳液,研究了R值[n(-NCO)∶n(-OH)]、DMPA用量、中和度和温度等对乳液外观、黏度、吸水率和稳定性等影响。结果表明:当R=2.0～2 5、w(DMPA)=5%、预聚温度为80℃和中和温度为40℃时,WPU乳液符合印刷油墨的使用要求。     

提高水性聚氨酯耐水性的研究

为了制备耐水性能较好的水性聚氨酯(WPU),以聚酯二元醇(PBA)、甲苯二异氰酸酯(TDI)和二羟甲基丙酸(DMPA)等为主要原料合成了WPU乳液,着重探讨了DMPA含量、R值[即n(-NCO)/n(-OH)]和交联剂对WPU胶膜耐水性能的影响。实验结果表明,当w(DMPA)=4%、R=1.5时,制得的WPU胶膜耐水性较好;采用不同的室温交联剂对WPU进行交联改性,当w(氮丙啶型交联剂A)=3%时(相对于WPU乳液干固量而言),WPU胶膜的吸水率降低至3%左右,并具有较好的持久耐水性。     

有机磷阻燃剂改性水性聚氨酯的制备

以聚己二酸-1,4-丁二醇酯二醇(PBA)、2,2-二羟甲基丙酸(DMPA)、异佛尔酮二异氰酸酯(IPDI)和有机磷阻燃剂10-(2,5-二羟基苯基)-10-氢-9-氧杂-10-膦杂菲-10-氧化物(DOPO-HQ)等为原料制备了阻燃型水性聚氨酯(WPU),考察了DOPO-HQ含量对WPU的黏度、硬度、力学性能和氧指数(LOI)等影响。结果表明:当DOPO-HQ含量从0增至12%(相对于PBA质量而言)时,WPU的黏度降低,成膜硬度增大,断裂伸长率下降,而拉伸强度由11.02 MPa提高到23.76 MPa,LOI由21.0%提高到27.2%(达到难燃级别)。     

Influence of preparation method on adhesion and drying performances of polyurethane dispersion

Waterborne polyurethane (WPU) dispersions with a high solid content were prepared by one-step and two-step methods with polyester and polyether type macromolecular diols as the main raw materials. The effects of two synthesis methods on the properties of WPU of polyester and polyether were studied. Fourier transform infrared spectroscopy, particle size and distribution, and Thermogravimetric analysis (TGA) measurements were utilized to characterize the structure. The dryness test results showed that the WPU synthesized with polyester diol as the soft segment by the two-step method had the best drying. In addition, the microstructure of WPU was characterized by transmission electron microscopy, which confirmed that WPU was mainly spherical structure. TGA and scanning electron microscopy results showed that the microphase separation between the soft and hard segments of WPU prepared by the two-step method was weaker, the hydrogen bonding was stronger, the adhesion, and thermal stability of WPU was improved.     

Bio-based waterborne polyurethane structural color films with high stability

In recent years, structural colors derived from photonic crystals (PCs) with a periodically ordered nanostructure are gorgeous and iridescent, but once their structure is destroyed, they will fade. In this work, the feasibility of the application of bio-based waterborne polyurethanes (WPU) in structural color films was explored. The structural stability of PCs is enhanced bio-based WPU as a kind of green product, which can replace solvent polyurethane one. A tung oil polyol (TOP) is fabricated by one-step method with simple purification process and used to prepare waterborne polyurethane dispersions (WPUD). More introduction of TOP into the WPUD may help improve tensile strength and hydrophobic capability. It shows excellent mechanical properties with 16.8 MPa in tensile strength and water contact angle 109.5°. The SEM images confirmed that bio-based WPU is more conducive to the self-assembly of silica particles than traditional WPU.     

Flame Retardant Modified Bio-Based Waterborne Polyurethane Dispersions Derived from Castor Oil and Soy Polyol

Although tremendous efforts have been dedicated to developing environmentally friendly bio-based waterborne polyurethane (WPU) dispersions from vegetable oil, the fabrication of WPU dispersions solely derived from vegetable oil-based polyol with excellent comprehensive properties is still challenging. In the present work, novel bio-based WPU dispersions derived from castor oil and soy polyol is successfully modified by phosphorus-nitrogen chain extender [bis(2-hydroxyethyl)amino]-methyl-phosphonic acid dimethyl ester (BH). The structure and properties of the dispersions and films are characterized systematically by Fourier transform infrared spectroscopy, thermogravimetric analysis , mechanical test, and limiting oxygen index (LOI), etc. The results indicate that bio-based WPU films display moderate mechanical performance by adjusting BH content, and the WPU film containing 100% BH with 47.8% biobased content has a tensile strength of 8 MPa and the highest Young's modulus of 62.3 MPa. The incorporation of BH can increase the production of char residue. The flame retardancy of WPU films increase gradually with the BH molar content, and the LOI value of the WPU100 with 1.53 wt% phosphorus content can reach as high as 28.1%. This work may provide a new approach to develop high biobased content, eco-friendly, flame retardant WPU for application in the surface coating industry.     

水性聚氨酯的结晶动力学参数及其在鞋用胶黏剂的应用

以聚己二酸1,4-丁二醇酯（PBA）、六亚甲基二异氰酸酯（HDI）和异佛尔酮二异氰酸酯（IPDI）为主要原料,制备了不同软段分子量和不同硬段含量的水性聚氨酯（WPU）乳液。采用DSC技术表征了WPU胶膜在非等温和等温条件下的结晶行为,并以莫志深方程和Avrami方程为模型,对WPU胶膜的结晶行为进行了研究。WPU胶膜的非等温结晶动力学分析结果表明,随着WPU相对结晶度的增加,非等温结晶动力学参数F（T）增大,说明适当提高活化温度可提高WPU胶黏剂的结晶速率和初黏强度;WPU胶膜的等温动力学分析结果表明,不同软段分子量和不同硬段含量的WPU胶膜的等温结晶动力学参数t_1/2与相应WPU胶黏剂的开放时间存在对应关系,即t_1/2较大者,相应WPU胶黏剂的开放时间较长。     

Effects of the reagent molar ratio on the phase separation and properties of waterborne polyurethane for application in a water‐based ink binder

Waterborne polyurethane (WPU) dispersions with a high solid content and low viscosity were prepared successfully by a two‐step polymerization with isophorone diisocyanate, poly(propylene glycol), and dimethylol propionic acid as the main raw materials. The molar ratio of hard segments to soft segments was controlled to investigate its influence on the particle size, particle morphology, stability of dispersions, and final properties of the WPU films. Measurements including attenuated total reflectance/Fourier transform infrared spectroscopy, transmission electron microscopy, differential scanning calorimetry, thermogravimetric analysis, X‐ray diffraction, polarizing optical microscopy, and contact angle tests were used to characterize the bulk structures, phase separation, thermal stability, crystallinity, and wettability of the WPU dispersions. The results indicate that all of the WPU dispersions with a high solid content (ca. 40 wt %) and low viscosity (ca. 20–50 mPa s) displayed excellent stability. The prepared WPU dispersions with acetone contents of 5–7 wt % could be used directly as an ink binder without removing the acetone; this is beneficial to industrial applications of water‐based ink binders. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45406.     

Preparation and characterization of a polydimethylsiloxane‐modified,epoxy‐resin‐based polyol dispersion and its crosslinked films

Waterborne polydimethylsiloxane‐modified epoxy‐resin‐based polyol dispersions were synthesized by the reaction of 2,4‐toluene diisocyanate with 2,2‐bis(hydroxymethyl) propionic acid, hydroxypropyl‐terminated polydimethylsiloxane (HTPDMS), and bisphenol A epoxy resin based polyol. These HTPDMS‐modified polyol dispersions exhibited a small particle size and an excellent dispersion stability. Two‐component waterborne polyurethane (2K‐WPU) was prepared from the HTPDMS‐modified polyol dispersion and a hydrophilic‐modified polyisocyanate. The structure of the HTPDMS‐modified polyol and its crosslinked 2K‐WPU films (SEFs) were characterized with Fourier transform infrared and NMR spectroscopies. The effects of the HTPDMS content on the mechanical and thermal properties of the resulting SEFs were investigated. The results show that the thermal stability of the crosslinked SEFs was enhanced with increasing HTPDMS content, whereas the modulus, tensile strength, and pencil hardness values of the films decreased with increasing HTPDMS content. Siloxane segments migrated onto the surface during the film‐formation process. The contact angle of the films increased from 71 to 96 °, and the water absorption ratio of the films decreased from 6.6 to 5.0% when the HTPDMS content in the films increased from 0 to 10%. These results indicate that the water resistance of the films was enhanced by the introduction of HTPDMS into the 2K‐WPU networks. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44342.     

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.     

Preparation and characterization of modified castor oil via photo-click chemistry for UV-curable waterborne polyurethane with enhanced water resistance and low conductive percolation threshold

A castor oil (CO) was modified via thiol-ene click chemistry reaction between CO and 3-mercaptopropyl trimethoxysilane, with the conversion of CC bonds of CO over 99% based on ¹HNMR spectra. The obtained modified castor oil (MCO) was used as a biobased polyol to prepare waterborne polyurethane (WPU) dispersions. The modification of CO exhibited a great effect on the properties of WPU dispersions and coatings, and an obvious change is the improvement of the water resistance of WPU coatings. WPU dispersions with MCO had good storage stability. A WPU coating with 7% MCO had high surface hydrophobicity, and its water absorption was as low as 3.2%. Conductive carbon black filled WPU coatings with MCO were cured by efficient UV radiation, and their conductive percolation threshold could decrease to 0.76%, which could be attributed to the well filler dispersion and strong filler-polymer interaction. The WPU dispersions are ecofriendly, and can be used to produce biobased WPU coatings with a great application potential in antistatic coating fields.     

Synthesis and characterization of ambient-temperature self-crosslinked waterborne polyurethanes with a novel diol chain extender bearing two ketone groups

A series of ambient-temperature self-crosslinked waterborne polyurethanes denoted as WBPUs were successfully synthesized by incorporating a novel diol chain extender bearing two ketone groups, 2,2-bis(4-(2-hydroxypropoxy levulinate)phenyl)-propane (BHLPP), which was prepared using 2,2-bis(4-(2,3-epoxypropoxy)phenyl)-propane and levulinic acid, with 4,4-methylenedicyclohexyl diisocyanate, poly-neopentylene adipate glycol, and dimethylolpropionic acid. After post-adding adipic dihydrazide (ADH), self-crosslinking was achieved by the reaction between the ketone (–CO–) of BHLPP and the hydrazine (–NHNH₂) of ADH during film formation. For comparison, noncrosslinked waterborne polyurethane (WPU) without BHLPP and ADH was prepared. The structure of BHLPP was characterized by IR and NMR. The properties of the WPU and WBPU dispersions were investigated by measuring the stability, particle size, and morphology. The effects of the ratio of n(–NHNH₂)/n(–CO–) and the content of BHLPP were studied in terms of hardness, water resistance, solvent resistance, and thermal properties of WPU and WBPU films. The WBPU dispersions exhibited excellent stability, bimodal distribution, and regular spheroid morphology. The optimal ratio of n(–NHNH₂)/n(–CO–) for ketone–hydrazine self-crosslinking was 0.75:1. Importantly, the WBPU films showed superior hardness, water resistance, solvent resistance, and thermal properties to WPU film.     

有机硅改性磺酸/羧酸型水性聚氨酯的研究

以聚醚多元醇(N-210)和2,4-甲苯二异氰酸酯(TDI)为原料,以自制的磺酸型亲水单体1,2-二羟基-3-丙磺酸钠(DHPA)和二羟甲基丙酸(DMPA)为扩链剂,采用氨丙基三甲氧基硅烷和氨乙基氨丙基三甲氧基硅烷对纯水性聚氨酯(WPU)进行改性,并对有机硅改性WPU胶膜的性能进行了研究。结果表明:WPU分别经两种不同结构的有机硅改性后,其胶膜的力学性能略高于未改性WPU,但耐水性和耐热性则明显高于未改性WPU。