Convenient synthesis of novel fluorinated polyurethane hybrid latexes and core-shell structures via emulsion polymerization process with self-emulsification of polyurethane

Novel fluorinated polyurethane hybrid latexes in the size range of 40–50 nm, fluoroalkyl acrylate as fluorinated monomers, with various fluorine content (F% = 9∼26 wt%) were successfully prepared via emulsion polymerization process without traditional emulsifier. The waterborne polyurethane, which was synthesized by using isophronediisocyanate, dimethylol propionic acid, polyethylene glycols, etc., served not only as copolymerizable macromonomer but also as polymeric high molecular weight emulsifier. The structures of polyurethane macromonomer and fluorinated polyurethane were characterized by Fourier transform infrared and H¹-NMR. Particle size, zeta potential, micromorphology of the latex par.ticles, and surface properties were investigated by dynamic light scattering, potential particle size analyzer, transmission electron microscopy, and contact angle measurement, respectively. Results illustrated that the advantage of this process is that the size of fluorinated polyurethane hybrid particle is less sensitive to the composition. Furthermore, it was showed that fluorinated polyurethane latex particles had core-shell structures, especially when the content of fluorine was 26.08 wt%. Moreover, there was an obvious migration of fluorinated groups to the surface during the formation of fluorinated polymer films, although fluorinated groups were covered by polyurethane in latex particles.     

A novel approach to fluorinated polyurethane by macromonomer copolymerization

For the first time, through macromonomer radical copolymerization, a novel fluorinated polyurethane (FPU) was synthesized based on partly acrylate-endcapped polyurethane macromonomers with hexafluorobutyl acrylate (HFBA). Partly acrylate-endcapped polyurethane (PU) macromonomers were synthesized using isophronediisocyanate (IPDI), dimethylol propionic acid (DMPA), polyethylene adipate glycols (PEA) etc. The novel fluorinated polymer, which bore PU side chains and fluorinated side chains, was confirmed by F¹⁹ NMR spectroscopy, X-ray photoelectron spectroscopy (XPS), elemental analysis, scanning electron spectroscopy (SEM) etc. Copolymerization of polyurethane macromonomers with hexafluorobutyl acrylate (HFBA) was briefly investigated. The surface tension of FPU solution was measured and showed sharply decrease compared to that of pure polyurethane. Results from SEM showed a uniform size distribution of phase micro-domains on the fracture surface of FPU.     

Synthesis and Application of Chitosan‐g‐PLLA Copolymers

The purpose of this paper is to study the synthesis and application of a new type of chitosan‐g‐poly(L‐lactide) copolymer with different grafting percentage in the presence of triethylamine. FTIR and ¹H NMR results indicate that grafting percentage of graft copolymers increases with the molar feeding ratio of L‐lactide to chitosan. The measurement of XRD and TG shows that graft copolymer exhibits low crystallinity and thermal degradation temperature. Static water contact angle testing suggests that graft copolymer has superior hydrophilicity compared with PLLA, which can be very useful for biomedical applications. 5‐Fluorouracil loaded copolymer microspheres were prepared by phase separation method. The size and distribution of microspheres were measured by a Laser particle analyzer. The microspheres with LLA:CS feeding molar rotio (15∶1) have a mean diameter of 332 nm with a narrow unimodal distribution. The spherical microspheres were observed by transmission electron microscopy (TEM). The microspheres shows good releasing property from drug release in vitro, and the drug release rate decreases as the increase of microspheres size.     

Synthesis and thermal properties of soybean oil-based waterborne polyurethane coatings

Waterborne polyurethane coatings were prepared by a polyaddition reaction using toluene diisocyanate (TDI), 2,2-di(hydroxy-methyl) propionic acid, soy-based polyols with different hydroxyl values, plus 2-hydroxyethyl methacrylate (HEMA) as chain termination agent, triethylamine as neutralization agent, and DBTDL as catalyst. Six soybean oil-based polyols were used in this study with hydroxyl values of 100, 115, 128, 140, 155, and 164 mg KOH g⁻¹, respectively. The molar ratio of polyol hydroxyl to DMPA was varied from 1.6 to 2.6. The storage stability of the waterborne polyurethane coatings was greater than 6 months. The thermal properties of the coating films were investigated by TG and DCS. The results show that the soy-based polyurethane films decomposed in three stages. The glass transition temperatures, T _g, of the soy-based polyurethane films increased with the hydroxyl number of the soy-based polyol.     

Preparation and properties of amino-terminated anionic waterborne-polyurethane-silica hybrid materials through a sol-gel process in the absence of an external catalyst

A series of polymer-silica hybrid materials consisting of amino-terminated anionic waterborne-polyurethane (WPU) and inorganic silica particles have been prepared through a sol-gel process in the absence of an external catalyst. Typically, amino-terminated anionic WPU was first synthesized from polycaprolactone, dimethylol propionic acid, and 4,4′-methylenebis(cyclohexyl isocyanate) with specific molar ratios, followed by further reaction with triethylamine and triethylene tetramine to give as-prepared WPU. The WPU obtained was characterized by FTIR spectroscopy and gel permeation chromatography. Subsequently, a series of hybrid materials with different silica contents were prepared by performing sol-gel reactions with tetraethyl orthosilicate (TEOS) in an amino-terminated WPU matrix without the addition of an external catalyst. This was followed by examination by transmission electron microscopy and ²⁹Si solid-state NMR. The terminated primary amine groups attached to the as-prepared WPU chains functioned as an internal base catalyst for the sol-gel process of TEOS. The effect of composition on the thermal stability, mechanical strength, surface wettability, and optical clarity of the hybrid materials was evaluated by the thermogravimetric analysis, dynamic mechanical analysis, contact angle measurement, and UV-visible transmission spectroscopy, respectively.     

氨基硅油扩链改性水性聚氨酯的研究

通过将由甲苯二异氰酸酯与聚四氢呋喃,二羟甲基丙酸反应制得的聚氨酯预聚体在低浓度氨基硅油的水乳液中扩链,合成了一种硅氧烷改性的聚氨酯水乳液,并用傅立叶红外光谱,ＥＳＣＡ能谱,接触角仪,电子拉力试验机,吸水率测定及乳液稳定性测试对其进行研究。     

Dehydration of acetic acid by pervaporation using SPEK-C/PVA blend membranes

Sulfonated cardo polyetherketone (SPEK-C) and poly(vinyl alcohol) (PVA) blend membranes were prepared by solution casting method and used in pervaporation (PV) dehydration of acetic acid. The membranes were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and contact angle meter. The results show that thermal crosslinking occurred to the membrane under high temperature annealing. The effective d-spacing (inter-segmental spacing) decreased with PVA content decreasing. The hydrophilicity of the blend membrane increased with SPEK-C content increasing. Swelling and sorption experiments show that the swelling degree of the blend membrane increased, however both the sorption and diffusion selectivities decreased with increasing PVA content. The diffusion selectivity is higher than the sorption selectivity. This suggests that PV dehydration of acetic acid is dominated by the diffusion process. The pervaporation separation index (PSI) of the membrane increases with increasing PVA content and arrives at a maximum when the SPEK-C/PVA ratio is 3/2, then decreases with further addition of PVA. The membrane has an encouraging separation performance with a flux of 492 g m⁻² h⁻¹ and separation factor of 59.3 at 50 °C at the feed water content 10 wt%.     

Poly(vinyl alcohol)/polyelectrolyte complex blend membrane for pervaporation dehydration of isopropanol

Poly(vinyl alcohol) (PVA) was blended with soluble polyelectrolyte complex (PEC) made from poly(diallyldimethylammonium chloride) (PDDA) and sodium carboxymethyl cellulose (CMCNa). Crystallinity, thermal transition, and thermal stability of the PVA/PEC blends were characterized by using wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and thermal gravity analysis (TGA), respectively. Surface morphology, cross-section and phase structure of the blend membranes were examined by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). Surface hydrophilicity and swelling behavior of the blend membranes were examined by water contact angle (CA) and swelling tests. Blend membranes were subjected to isopropanol dehydration, and effects of blend composition, feed composition and feed temperature on pervaporation performance are discussed in terms of phase structures of blend membranes. A performance of J = 1.35 kg/m² h, α = 1002, was obtained for blend membrane containing 50 wt% PEC in dehydrating 10 wt% water–isopropanol at 70 °C.     

Acid-Containing Tyrosine-Derived Polycarbonates: Wettability and Surface Reactivity

Tyrosine-derived polycarbonates having carboxylic acid pendant groups were characterized by water contact angle and X-ray photoelectron spectroscopy (XPS). A pronounce decrease of receding angle as well as contact angle hysteresis as a function of acid composition strongly indicated that the acid groups are more accessible at the water/polymer interface after hydration. pH dependent contact angle confirmed an existence of carboxylic acid groups in the surface region. The receding angle transition appearing in the pH range of 4-6 was a consequence of hydrophilicity change due to interconverting from carboxylic acid (-COOH) to carboxylate ion (-COO⁻). The surface compositions of imidazole-labeled polymers as analyzed by XPS were consistent with the bulk stoichiometry of the polymers. Reactivity of acid groups towards chemical reaction at the surface was also investigated. The acid groups at the surface of polymers were capable of adsorbing a significant amount of calcium ion from simulated body fluid and being activated by a reaction with N-hydroxysuccinimide.     

Synthesis and characterization of polyurethane ionomers with trimellitic anhydride and dimethylol propionic acid for waterborne self‐emulsifying dispersions

A new synthesis for polyurethane dispersions was developed using both trimellitic anhydride alone and in combination with dimethylol propionic acid as internal emulsifiers. During synthesis of the polyurethane ionomer, Fourier transform infrared spectroscopy was used for monitoring and characterizing both the polyaddition step and the anhydride ring opening process. Depending on the synthesis route, the carboxylic groups are either located at the end of the polymer backbone or additionally statistically distributed within the polymer chain itself. The effect of the carboxylic group's position on the chemical and physical properties, with particular reference to particle size and pH, was analyzed. Three different polyols were used to synthesize the polyurethane dispersions. Driven by the current trend to find renewable alternatives to petrochemical‐based raw materials, one bio‐based polyol was included for the synthesis. The effect of the different structures of the polyurethane dispersions (petrochemical‐ or bio‐based polyols) on mechanical properties and thermal behavior was investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 680–690     

Modified cotton fabrics with poly (3-(furan-2-carboamido) propionic acid) and poly (3-(furan-2-carboamido) propionic acid)/gelatin hydrogel for UV protection,antibacterial and electrical properties

This research aimed to prepare smart cotton fabrics with multi functions for antibacterial activity, UV protection and electrical conductivity via in situ coating with conductive polymer and conductive hydrogel. Therefore, 3-(furan-2-carboamido) propionic acid was synthesized followed by polymerization using ceric ammonium nitrate. In addition, cotton fabrics coated with 3-(furan-2-carboamido) propionic acid via in situ polymerization and by the hydrogel that based on poly (3-(furan-2-carboamido) propionic acid) and gelatin which have been performed via in situ gelation process. The chemical structure and morphology of the 3-(furan-2-carboamido) propionic acid (monomer) and the synthesized polymer (PFu) were investigated by H¹NMR, IR, SEM, TGA and DSC. Where, the treated fabrics (PFu-T and PFu-G-T) are characterized by SEM, FTIR and contact angle. Furthermore, the AC electrical conductivity and dielectric properties of PFu, PFu-T, PFu-G-T and blank were investigated over the frequency range of 20 Hz–10 MHz at room temperature using impedance spectroscopy where the electric conductivity values are 1.74 × 10^-5, 7.5 × 10^-8, 4 × 10^-7, 8.24 × 10^-11 (S·cm)^-1, respectively. In addition, the anti-bacterial activity of PFu-T, PFu-G-T and blank was assessed versus gram-positive and gram-negative bacteria where, PFu-G-T shows activity against Escherichia coli and Staphylococcus aureus. Moreover, PFu-T, PFu-G-T showed high UV protection especially for PFu-G-T.     

氟硅改性聚氨酯自组装膜的合成及性能

以甲苯二异氰酸酯、聚酯二元醇、2,2-二羟甲基丙酸和十三氟-1-辛醇等为原料合成了氟醇封端的聚氨酯预聚体(FPU)。 通过FPU侧链含有的羧基官能团与异氰酸酯基硅烷偶联剂(Si-NCO)反应制备了含硅氧烷官能团功能性树脂(FPUSi)。 采用红外光谱(FT-IR) 对产物结构进行了表征,用TGA和水接触角等测试了自组装薄膜的表面性能。 结果表明,在N2气氛围下,FPU和FPUSi的热失重温度（T5％）均为178 ℃;硅基表面经FPUSi自组装膜修饰后,其表面水接触角达到81°。 微摩擦测试结果表明,当载荷为400 mN时,FPUSi自组装薄膜的稳定摩擦系数达到0.09。     

硅氧烷改性水性聚氨酯的制备及性能

A series of novel aqueous emulsion of siloxane modified polyurethane (PU(PE-PSI)) were synthesized based on poly(propylene glycol) (PPG), polyether-grafted polysiloxane (PE PSI), 2,4-tolylene diisocyanate (TDI), dimethylol propionic acid (DMPA) and 1,4 butanediol (BDO) through a direct water emulsification of triethylamine (TEA). The aqueous emulsion was transparent and had a good stability. Fourier transform infrared spectroscopy (FTIR) was used to identify the structure of PU (PE PSI), indicating that the polysiloxane segment had been incorporated with polyurethane chain. Investigation of Electron Spectroscopy for Chemical Analysis (ESCA) and the water contact angle demonstrated that the siloxane migrated to the surface of film. The results also showed that PU(PE-PSI) was still a very good elastomer. With increasing the content of PE PSI, the resistance to water improved and tensile strength increased, while the ultimate elongation decreased slightly for the PU(PE-PSI) film.     

多代超支化水性聚氨酯的合成及表征

以甲苯-2,4-二异氰酸酯(TDI)、二羟甲基丙酸(DMPA)和二乙醇胺(DEOA)为原料通过偶合单体反应法合成了一系列不同代数的超支化水性聚氨酯(HPU),通过红外光谱(FT-IR)和核磁共振波谱（NMR）对其结构进行了表征,利用三检测器的凝胶渗透色谱(GPC3)测定各代产品分子量,采用热重分析仪(TG)和示差扫描量热仪(DSC)对各代HPU及类似化学组成的线性水性聚氨酯(LPU)的热性能进行测试分析对比,结果表明,合成各代HPU产率最高可达91%;TG分析表明各代数HPU与LPU具有相近的初始分解温度,大约在200℃左右,但各代HPU与LPU的分解历程明显不同;DSC结果表明各代HPU产品的玻璃化温度(Tg)明显高于LPU,同时随着代数增高,Tg逐步由115.2℃升高到150.3℃;对比各代HPU掺杂涂膜发现,随代数的增加,光泽度和硬度明显提高。     

Investigation of ultraviolet curable waterborne polyurethane acrylate dispersion based on hydroxyl-terminated polybutadiene

A new kind of ultraviolet (UV) curable waterborne polyurethane acrylate dispersion was synthesized based on hydroxyl-terminated polybutadiene (HTPB), poly-(propylene glycol) (PPG), isophorene diisocyanate (IPDI), 2-hydroxy ethyl acrylate (HEA) and dimethylol propionic acid (DMPA) after neutralizing by triethylamine (TEA). 2-Hydroxy-1-[4-2-hydroxyethoxy) phenyl]-2-methyl-1-propanone (Irgacure 2959) was used as a photoinitiator and deionized water as a diluent. Fourier transform infrared (FTIR) analysis was used to identify the chain structure of the UV-curable polyurethane prepolymer based on HTPB and the curing process. Effects of relative content of HTPB and PPG on emulsion stability, resistance to water and ethanol, thermal stability, compatibility of soft and hard segment, as well as the mechanical property of the cured film were investigated. Translated from Polymer Materials Science and Engineering, 2006, 22(3): 199–203 (in Chinese)     

Polyethersulfone sulfonated by chlorosulfonic acid and its membrane characteristics

Sulfonated polyethersulfone (SPES) was prepared by homogeneous method with chlorosulfonic acid as sulfonating agent and concentrated sulfuric acid as solvent. The presence of sulfonic acid groups in SPES was confirmed by ¹H NMR and FTIR. Thermogravimetric analysis (TGA) studies were carried out to investigate the thermal stability of SPES. Membranes were cast from SPES solutions in N-methyl-2-pyrrolidone. Tensile strength of prepared membranes decreased with degree of sulfonation (DS) but water uptakes of SPES membranes increased with DS. Compared with unsulfonated polyethersulfone membrane, the hydrophilicity of SPES membranes was increased, as shown by a reduced contact angle with water. Amorphous structures for SPES membranes were detected by X-ray diffraction. Atomic force microscopy phase images of the membranes clearly showed the hydrophilic domains at higher DS.     

Chitin Derivatives III Formation of Amidized Homologs of Chitosan

The kinetics of the formation of amidized homologs of chitosan from the ionic complexes of chitosan with four alkanoic acids, formic, acetic, propionic and butyric acid, have been studied. Their degrees of substitution (DS) and their thermal transitions have been investigated. The results suggest that heating of N-acylates of chitosan produces amidized chitosan homologs with DS ranging between 0.1 and 0.6 as determined by solid state NMR. Thermal analysis by DMTA revealed that the ionic complexes of chitosan with formic, acetic, propionic, and butyric acids, as well as the respective amidized chitosan homologs, display two transitions designated as - and -relaxation. There was no indication of melting. The -relaxations of the ionic complexes were more pronounced than those of their respective amidized chitosan derivatives. The ultimate T _g of the amidized chitosan homologs declined stepwise with acyl substituent size. The T _g-behavior was attributed to both substituent size and DS. Kinetic analysis using T _g-changes with heating time can be used to describe the kinetics of amidization. The formation of amidized chitosan homologs followed first order rate kinetics in a two-stage process, as was reported previously. The activation energy for amidization was constant irrespective of the acid used in the chitosan complex as well as the DS at ultimate T _g. It was 14±1kcal/mol initially and 21±2kcal/mol in the second stage. Since the transition from first to second stage occurs after the change from rubbery to glassy state (vitrification), vitrification is suspected to be responsible for the two-stage kinetics.     

PCDL型超支化水性聚氨酯的合成与性能

以甲苯-2,4-二异氰酸酯（TDI）、聚碳酸酯二醇（PCDL）、二羟甲基丙酸（DMPA）和二乙醇胺（DEOA）为原料,采用A₂＋bB₂共聚合路线合成了具有超支化结构的水性聚氨酯（HBAPU）乳液。采用红外光谱（FT-IR）、核磁共振（13C NMR）对产物结构进行了表征,证实了超支化聚氨酯的支化度随 n(NCO)/n(OH)比值的增大而增大。用PCS、TG、电子拉力机对产物的性能进行了测试,同时也对胶膜的耐水性进行了测试,发现在DMPA含量为0.4 mmol/g时,HBAPU的粒径仅有20.57 nm,而线性水性聚氨酯粒径有130.91 nm,并且HBAPU具有良好的耐水性、热稳定性和较高的拉伸强度。     

Synthesis and characterization of phenyl polysiloxane modified polyurea/polyurethanes

A series of phenyl polysiloxane‐modified polyurea/polyurethanes ( SPUs ) with different silicone loadings (10, 20, 30, and 40 wt %) have been designed and synthesized. The structures of SPUs were confirmed by ¹H NMR, ¹³C NMR, and FT‐IR. The impact of phenyl polysiloxane content on the properties of SPUs was fully studied. The residual methoxy groups on silicon could help SPUs form interpenetrating networks accompanying with the residual isocyanate under moisture, which was different with the conventional moisture‐crosslinking polyurethane system. The properties of SPUs films have been fully researched by attenuated total reflection flourier transformed infrared spectroscopy, thermal analysis, tensile tests, water contact angle, X‐ray photoelectron spectroscopy, SEM, and AFM. Results indicated that the introduction of phenyl polysiloxane improved the thermal stability and remarkably increased the water contact angles accompanying with a comparable mechanical strength to the pure polyurethane. Meanwhile, it also brought out the decreased microphase separation and water absorption. The obvious surface migration has been observed in the SPUs , which changed their surface properties. Some voids were observed in all moisture curing SPUs system, but the phenyl silicone content impacted on the numbers and sizes of the voids. The phenyl groups introduced and carbon dioxide produced in the crosslinking procedure helped to form and stabilize the voids in the SPUs . © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1794–1805     

Biodegradable polyester/modified mesoporous silica composites for effective bone repair with self‐reinforced properties

A series novel composites based on poly(_L‐lactide) (PLLA) oligomer modified mesoporous silica (MCM41) homogeneous dispersed into poly(_L‐lactide‐co‐trimethylene carbonate‐co‐glycolide) (PLTG) terpolymer has been successfully prepared. The structure of PLTG terpolymer was characterized by ¹H NMR. The structure and properties of modified and unmodified MCM41 were attested by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyzer (TGA), X‐ray diffraction (XRD), N₂ adsorption–desorption, scanning electron microscope (SEM), and transmission electron microscope (TEM), which demonstrated that the MCM41 was successfully grafted by the PLLA oligomer. The effect of different concentration of modified MCM41 in PLTG matrix on thermal properties, mechanical properties, and hydrophilicity was investigated by TGA, differential scanning calorimetry (DSC), mechanical testing, contact angle measurement, and SEM. The results of mechanical tests showed that 5 wt% of modified MCM41 nanoparticles gave rise to optimal reinforcing effect. The tensile strength, Young's modulus, and elongation at break of the PLTG/PLLA‐MCM41 (5%) composites were 33.2 Mpa, 1.58 Gpa, and 268.7%, respectively, which were all higher than the PLTG/MCM41 (5%) composites and pristine PLTG matrix, which were due to good interfacial adhesion between the PLTG matrix and MCM41 nanoparticles. TGA and DSC have shown that 5% modified MCM41 in the PLTG increased the temperature of composite degradation and T_g. Water contact angle measurement showed the hydrophilicity of the composites increases with the increase of modified MCM41 content. The live/dead assay showed that the modified MCM41 existing on the PLTG matrix presents very excellent cytocompatibility. Therefore, the novel composite material represents promising way for bone tissue engineering application.