双亲性聚氨酯的制备和应用进展

综述了双亲性聚氨酯的结构分类,各种制备方法和亲疏水基团的引入方法,介绍了双亲性聚氨酯材料在弹性体、医用材料和表面活性剂等方面的应用。     

Synthesis of novel amphiphilic pH‐sensitive polyurethane networks through W/O soap‐free emulsion polymerization process. II. Mechanical property and biphasic swelling behaviors

Amphiphilic urethane acrylate anionomer (UAA) chains exhibited very different solution properties in various solvents, such as water, dioxane, and dimethyl sulfoxide (DMSO). UAA chains showed a polyelectrolyte effect in a highly polar solvent, DMSO, but gave constant viscosity at various concentrations in aqueous solution, because of the microstructural difference of the UAA chain formed in solvents. In polar solvents (water and DMSO), the swelling of UAA networks prepared with water and dioxane strongly depended on the properties of the hydrophilic domains. In low and nonpolar solvents (dioxane and methylene chloride), the swelling of UAA networks was only dependent on the property of the hydrophobic segments. In the polar solvent medium, UAAG networks prepared with water exhibited greater swelling than UADG networks prepared with dioxane. Concerning swelling in a nonpolar solvent, however, UADG networks showed greater swelling than UAAG networks. This is because of the microstructural difference between these networks, which was confirmed by the mechanical property measurement. UAAG networks, having highly microphase‐separated structures, had higher modulus and transition temperatures than the UADG networks, because of the microstructural difference between UADG and UAAG networks. Both the UAAG and UADG networks take up two immiscible solvents simultaneously within their hydrophobic and hydrophilic domains. Equilibrium swelling ratio of these networks in two immiscible solvents strongly depends on their hydrophilic/hydrophobic balance that is controlled by the type of solvent used in the network synthesis. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 621–630, 2001     

Synthesis of novel amphiphilic pH‐sensitive polyurethane networks through water‐in‐oil soap‐free emulsion polymerization process. I. Microstructural differences and swelling behaviors

pH‐sensitive amphiphilic networks are synthesized from urethane acrylate anionomer (UAA) precursor chains. The microstructures of these networks are very sensitive to the nature of and the amount of solvent used during crosslinking. Whereas dioxane forms relatively homogenous solution, water preferentially interacts with hydrophilic segment of UAA chains, causing the microphase separation between hydrophilic moieties and hydrophobic main chains. This microphase separation was locked‐in by crosslinking reaction, enhancing largely the hydrophilicity of UAA networks and the hydrophobic aggregation. The UAA gels, prepared with water (UAAG) and/or dioxane (UADG), exhibit quite different swelling behaviors in the same dissolution medium because of their completely different microstructures. The improved hydrophilicity of UAAG gels due to the hydrophilic/hydrophobic microphase separation is confirmed by measuring the contact angle to water. These microphase‐separated hydrophilic domains on UAA gel matrix, which are observed by scanning electron microscopy measurement, influence the mechanical property of dried UAA gels as well. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 2115–2127, 2000     

Mechanical property and swelling behavior of semi-interpenetrating polymer networks based on polyvinyl alcohol and polyurethane

We have studied the mechanical property and swelling behavior of semi-interpenetrating polymer networks (semi-IPNs) of poly(vinyl alcohol) (PVA) and polyurethane (PU) with reactive groups under different experimental conditions. Tensile strength and elongation of these semi-IPNs are strongly dependent on the composition of IPNs and degree of PU crosslinking. It is clear that the composition of PVA and PU forms different IPNs morphology, which would determine the final mechanical property. The experimental results also demonstrate that the degree of crosslinking, which is controlled by heat treating temperature time, and amount of reactive groups, affects the swelling behavior of IPNs. With a change in the degree of crosslinking, the degree of swelling of IPNs is also different. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 473–479, 1998     

The swelling behavior of interpenetrating polymer networks composed of polyurethane and unsaturated polyester

The kinetics of swelling and the sorption performance were observed for the polymer compositions with interpenetrating polymer networks made up of polyurethane and unsaturated polyester during their exposure to chlorobenzene at 25°C. It was found that the rates for solvent transport and solvent absorption processes were controlled by the chemical composition of the formulation studied. On the basis of the observed swelling process, parameters could be assessed which were specific for the mass transfer process, i.e., diffusion coefficient, sorption coefficient, and permeability coefficient. Moreover, an attempt was made to evaluate structural parameters that describe topology of the obtained networks. It was found that the increasing share of polyurethane in the composition reduced crosslinking density in the polyester network that resulted in faster diffusion of the solvent and higher sorption capacity for the solvent. The higher the styrene content in the composition, the higher the crosslinking density in the system, and hence the diffusion of solvent and its sorption inside the polymer network was much more difficult. In the scanning electron microscope analysis of samples, which had been subjected to swelling, no leaching was observed for any phase present in the system, despite phase separation for both the components. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3511–3519, 2006     

聚醚型吸水膨胀聚氨酯弹性体的合成

采用亲水性聚醚多元醇(PPE)与甲苯二异氰酸酯(TDI)反应的预聚体,与混合扩链剂制备了吸水膨胀聚氨酯弹性体。实验结果表明:当聚乙二醇醚(PEG)与聚丙二醇醚(PPG)的物质的量比为6∶4,PEG相对分子质量为2 000,预聚体中异氰酸酯基(—NCO)的质量分数为5.2%;采用混合扩链剂,且1、4-丁二醇与丙三醇的物质的量比为2∶1,增塑剂邻苯二甲酸二辛酯(DOP)的质量分数控制在8%时,制备的聚氨酯弹性体吸水膨胀率高,综合性能良好。     

Influence of swelling solutions on the behavior of cholesteric networks

The swelling behavior of an ethyl‐cyanoethyl cellulose/crosslinked poly(acrylic acid) cholesteric network in different swelling solutions was studied. The swelling behavior of the cholesteric network was reversible in acid or neutral solutions and was irreversible in basic solutions. The cholesteric network retained the cholesteric structure during the swelling process in NaCl aqueous solutions, and the swelling behavior was incompletely reversible. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 724–729, 2005     

双液型遇水膨胀聚氨酯密封胶的研制

介绍了双液型遇水膨胀聚氨酯密封胶的研究。该密封胶以水溶性聚氨酯预聚体为A组分,复合固化剂、填料和增塑剂为B组分,具有遇水膨胀的特殊功能。重点讨论了填料用量、增塑剂用量、固化剂形态对密封胶性能的影响。     

Novel amphiphilic polyurethane networks: gelation mechanism and swelling behaviors

Amphiphilic polyurethane gels can be prepared using poly(ethylene glycol)-modified urethane acrylate (PMUA) through two types of methods. When PMUA gels were prepared at an aqueous phase, droplet coalescence and gelation occurred at the same time, so the microstructure of these gels (UAHG) was similar to that of PMUA emulsion which was formed by the microphase separation between hydrophilic and hydrophobic domains. In the case of UAHG gels, as the composition ratio of water to PMUA increased, swelling in water increased, but swelling in dioxane was slightly decreased. For the other kind of PMUA gels prepared using dioxane through a conventional gelation process (UADG), swelling in dioxane greatly increased with increasing of the composition ratio of dioxane; however, swelling of these gels in water was very low. The difference in swelling behavior between UAHG and UADG gels was due to the difference of microstructures between these gels which also influenced the mechanical properties. Additionally, the microstructures of UADG and UAHG gels were able to be confirmed using scanning electron microscopy (SEM) and contact angle measurement. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 821-832, 1997     

Synthesis and morphology transformation of amphiphilic diblock polyurethane copolymers in aqueous solution

Amphiphilic block copolymers possess both hydrophobic and hydrophilic properties and can form versatile micellar structures in aqueous solution. The aim of the research presented was to prepare a series of non‐ionic amphiphilic diblock polyurethane copolymers (PUn) based on isophorone diisocyanate, monoallyl‐end‐capped poly(ethylene oxide) and poly(propylene oxide) (PPO), followed by an investigation of their micellization properties and morphology transformation in aqueous solution. The PUn samples were synthesized by condensation polymerization. These polyurethanes exhibit surface tension as low as 33.7–37.0 mN m^?1. There is an obvious decrease in critical micelle concentration as the hydrophobic PPO molecular weight increases. According to transmission electron microscopy, the morphology of aggregates of the copolymers can be tuned by varying the concentration in aqueous solution rather than organic solvent. For example, for PU7, large compound micelles are produced instead of vesicles. For PU17, the concentration can be used to control the size and thickness of vesicles. Vesicle size increases from 60 to 500 nm and vesicle thickness from 40 to 60 nm with concentration ranging from 0.003 to 0.03 wt%. The study shows that the copolymers in aqueous solution have excellent surface activities. In addition, they can self‐assemble into large compound micelles or vesicles at certain concentrations. Moreover, the synthesis method described allows one to obtain a desired morphology of aggregates by adjusting the composition of hydrophilic and hydrophobic segments, which provides a novel and simple way to obtain particles on the nanometer scale. Copyright © 2010 Society of Chemical Industry     

The influence of polycaprolactone content on the surface properties of polyurethane networks

The aim of this work was to examine the influence of polycaprolactone (PCL) as a soft segment (SS) on the surface properties of polyurethane networks (PUNs). Five PUNs with different SS content (from 10 to 50 wt%) were prepared using Boltorn® aliphatic hyperbranched polyester of the second pseudo generation and isophorone diisocyanate as components of hard segments. The structure, hydrophobicity, wettability, and swelling behavior of these PUNs were investigated. Primarily, the obtained results showed that properties of prepared PUNs strongly depend on the content of SS that is, PCL. It has been established that the increase of SS content reduced the degree of hydrogen bonding in PUNs. Also, the increase of the SS content in PUNs induced appearance of more pronounced microphase separated morphology, better hydrophobicity and non-wetting with diiodomethane. Simultaneously, the increase of the SS content led to the decrease of contact angles with formamide, and surface free energy of the prepared PUNs. These PUNs show good surface properties that are required for their potential application such as coatings.     

一种双亲性共网络树脂的制备及其应用

用聚乙二醇二丙烯酸酯与甲基丙烯酸十八酯进行自由基共聚合反应,得到一种双亲性共网络树脂。对树脂结构进行了表征和亲油与亲水性能研究,并将其用作药物载体。结果发现,树脂同时具有亲油和亲水性能,对油品三氯甲烷的亲油倍率可达16.6 g/g;随着引入亲水基团的增加,树脂的亲水倍率逐渐增加;载体对于布洛芬有良好的负载率和缓释效果。通过热重分析表明,树脂在通常使用条件下具有很好的稳定性。     

Star‐shaped amphiphilic block polyurethane with pentaerythritol core for a hydrophobic drug delivery carrier

To obtain polyurethane micelles with excellent stability as a drug delivery carrier, star‐shaped amphiphilic block polyurethane (SAPU) was successfully synthesized by the ‘arm‐first’ method, using methoxypoly(ethylene glycol) and poly(ε‐caprolactone) diol as soft segments, hexamethylene diisocyanate as hard segments and pentaerythritol as the core. The structure of the SAPU was characterized by Fourier transform infrared spectroscopy, ¹H NMR spectroscopy and gel permeation chromatography. The micellization behaviour and micelle properties of SAPU were measured by the pyrene fluorescence probe technique, ¹H NMR, SEM and dynamic light scattering. The results indicated that SAPU could self‐assemble to form nanomicelles in aqueous solution and that the micelles showed excellent stability upon dilution and storage. Indometacin as a model drug could be incorporated into SAPU micelles and be released sustainedly. Meanwhile, the hydrophilic segment content and the molecular weight of SAPU had effects on the micelle properties. In addition, SAPU exhibited good cytocompatibility estimated by methylthiazole‐tetrazolium assay. © 2016 Society of Chemical Industry     

Synthesis and characterization of amphiphilic polymer networks based on acrylated poly(ϵ‐caprolactone) and N‐vinylpyrrolidone

New amphiphilic polymer networks were synthesized by the free‐radical copolymerization of α,ω‐diacryl polycaprolactone (DAPCL) and N‐vinylpyrrolidone (NVP), which was initiated by 0.5% azobisisobutyronitrile at 70°C. The chemical structures of the networks were characterized by proton nuclear magnetic resonance spectrometry. The NVP/DAPCL feed ratio played an important role in the crosslinking process. The synthesized amphiphilic polymer networks exhibited controlled swelling properties in water and organic solvents (ethanol, acetones, and toluene). A porous structure was observed for the amphiphilic polymer networks under a scanning electron microscope. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

基于超分子相互作用的自愈合聚氨酯材料

聚氨酯材料由于其固有的氢键结构被认为是一种理想的自愈合材料。将超分子化学体系引入到聚氨酯中,可以获得性能更加出色的自愈合材料。这些基于超分子相互作用的自愈合聚氨酯材料在受损后能够恢复其大部分物理和化学性质,具有优异的性能。该文首先从不同类型的愈合机理出发,综述了近年来基于超分子相互作用的自愈合聚氨酯材料,包括氢键结合体系、基于芳香基的π-π堆积体系、链段侧链中含有离子基团并彼此形成交联点的离子交联聚合物体系、金属离子与配体进行配位引起材料交联的金属配体相互作用体系、大环分子与特定大小的分子形成包合物的主客互动体系。然后展望了自愈合聚氨酯未来发展优势。     

Pore entry effects in the solvent-induced swelling of low-rank coals

The swelling of a low-rank coal under the influence of various solvents is examined and results compared with those for a similar coal in briquetted from. Results are interpreted in terms of the effects of briquetting on pore structure.     

依兰煤在液化溶剂中的溶胀动力学研究

笔者以依兰煤为原料,研究了依兰煤在室温至2000℃范围内在液化起始溶剂和循环溶剂中的溶胀行为,并确定了依兰煤在试验条件下的溶胀动力学参数。试验结果表明：依兰煤在液化起始溶剂和循环溶剂中的溶胀度随溶胀温度的增加和溶胀时间的延长而增大;依兰煤在这2种溶剂中的溶胀都是受Case-Ⅰ扩散控制为主的过程,其溶胀活化能分别为4．18和4．22kJ·mol^-1。     

Structure and properties of semiinterpenetrating polymer networks based on polyurethane and nitrochitosan

Two semiinterpenetrating polymer networks (semi‐IPNs) based on trihydroxyl methylpropane–polyurethane (T‐PU) or castor oil–polyurethane (C‐PU) were prepared by curing the mixed solution of the polyurethane prepolymer and nitrochitosan (NCH). During the curing process, crosslinking and grafting reaction between the molecules of the PU prepolymer and NCH occurred, because of the high reactivity of remaining hydroxyl groups in the NCH with ? NCO groups of PU. The structure of the original semi‐IPN sheets and the sheets treated with acetone were studied by infrared, ¹³C‐NMR, scanning electron microscopy, and dynamic mechanical analysis, showing interpenetration of NCH molecules into the PU networks. When nitrochitosan content (C_NCH) was lower than 10 wt %, the semi‐IPN sheets T‐PU and C‐PU had higher density and tensile strength (σ_b) than the systems with C_NCH more than 20%. The trihydroxymethyl propane‐based PU reacted more readily with nitrochitosan to form the semi‐IPNs than castor oil‐based PU. The semi‐IPN coatings T‐PU and C‐PU were used to coat cellophane, resulting in intimate interfacial bonding. The mechanical strength and water resistivity of the cellophane coated with T‐PU coating were improved remarkably. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3109–3117, 2001     

Coal swelling in binary solvent mixtures: Pyridine—chlorobenzene and N,N-dimethylaniline—alcohol

Illinois No. 6 coal has been swollen in pyridine—chlorobenzene mixture and the composition of the solvent inside the coal measured. Pyridine disrupts the non-covalent crosslinks in coal, so the addition of very small amounts of pyridine leads to an enormous increase in the uptake of chlorobenzene by the coal. The sites which interact specifically with pyridine can be titrated by measuring the composition of the solvent absorbed by the coal. Bruceton coal has been swollen by mixtures of alcohols with N,N-dimethylaniline. About the same amount of methanol, ethanol, and propanol are absorbed by pyridine-extracted coal, suggesting the existence of specific sites for alcohol binding. Significantly less t-butanol is bound, presumably due to steric effects. The swelling behaviour of extracted and unextracted coals are quite different, since pyridine extraction destroys many non-covalent crosslinks. The interactions of these solvents with coal are very sensitive to the ability of the solvents to interact specifically with the coal and, in doing so, to destroy non-covalent crosslinks.     

水分对聚氨酯微孔弹性体工艺性能及结构的影响

采用一步法制备聚氨酯微孔弹性体材料,考察了聚醚组分中水分对聚氨酯微孔弹性体工艺、性能及微观结构的影响。结果表明,随着聚醚组分中水分含量的增加,聚合反应乳白时间、凝胶时间延长;材料的硬度先略微升高,之后缓慢下降;材料的密度、挠曲模量、拉伸强度、断裂伸长率均是先缓慢下降,之后下降显著;材料的发泡趋势更加明显,泡孔数增多,泡孔间距缩短。