Synthesis and characterization of polyurethane coatings derived from polyols synthesized with glycerol, phthalic anhydride and oleic acid

Polyester polyols, with various oleic acid contents were used in the preparation of polyurethane (PUR) coatings. The polyols were designated as Alk28, Alk40 and Alk65, in which 28, 40 and 65 represents the percentages of oleic acid in the respective formulations. The physical properties of the polyols such as acid value and hydroxyl value have been determined and the infrared (IR) spectroscopic analysis of the polyols is reported. The polyols were reacted with aromatic isocyanate (toluene 2,4-diisocyanate, TDI) to form PUR coatings. The effects of varied NCO/OH ratio and oleic acid content of polyols on physical properties of PUR coatings on mild steel panel were determined. The characterization of PUR coatings carried out by IR spectroscopic analysis and physico-chemical properties such as drying time, pencil hardness, adhesion properties, solvent resistance and corrosion/chemical resistant determination were reported. The coatings obtained from polyol Alk28, exhibits the best overall properties followed by Alk40. PUR coatings from Alk65 were softer. As the NCO/OH ratio of the coatings increased, there were progressive increases in mechanical and anticorrosive properties for all the coatings. Overall, these studies showed that the material holds promise for use as effective surface coating compound by designing the formulation of the desired performance.     

Synthesis and characterization of polyurethane coatings derived from polyols synthesized with glycerol,phthalic anhydride and oleic acid

Polyester polyols, with various oleic acid contents were used in the preparation of polyurethane (PUR) coatings. The polyols were designated as Alk28, Alk40 and Alk65, in which 28, 40 and 65 represents the percentages of oleic acid in the respective formulations. The physical properties of the polyols such as acid value and hydroxyl value have been determined and the infrared (IR) spectroscopic analysis of the polyols is reported. The polyols were reacted with aromatic isocyanate (toluene 2,4-diisocyanate, TDI) to form PUR coatings. The effects of varied NCO/OH ratio and oleic acid content of polyols on physical properties of PUR coatings on mild steel panel were determined. The characterization of PUR coatings carried out by IR spectroscopic analysis and physico-chemical properties such as drying time, pencil hardness, adhesion properties, solvent resistance and corrosion/chemical resistant determination were reported. The coatings obtained from polyol Alk28, exhibits the best overall properties followed by Alk40. PUR coatings from Alk65 were softer. As the NCO/OH ratio of the coatings increased, there were progressive increases in mechanical and anticorrosive properties for all the coatings. Overall, these studies showed that the material holds promise for use as effective surface coating compound by designing the formulation of the desired performance.     

Effect of oleic acid content and chemical crosslinking on the properties of palm oil‐based polyurethane coatings

Polyurethanes (PU) were prepared by reacting palm oil‐based polyols and aromatic diisocyanate (toluene 2, 4 diisocyanates). The content of oleic acid was varied in the polyester polyols and the hydroxyl value was fixed to be 140 mg KOH g^?1. The NCO/OH ratios were varied to 1.2, 1.4, and 1.6. Crosslinking density of the PU was measured by swelling in toluene at room temperature. It was found that the crosslinking increased with decreasing oleic acid content and increasing NCO/OH ratio. The samples were assessed by thermogravimetric analysis, differential scanning calorimetric, and short‐term creep measurements. The highest rupture strength of the PU films was 36 MPa and thermostability improved as the oleic acid content and the NCO/OH ratios were increased in the sample. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Electrical behavior of polyurethane derived from polyols synthesized with glycerol,phthalic anhydride,and oleic acid

The direct current (DC) and alternating current (AC) conductivity of polyurethane (PUR) derived from polyols synthesized with glycerol, phthalic anhydride, and oleic acid were investigated in this article. The PUR was prepared by varying the oleic acid content in polyol (28, 40, and 65%) and the NCO/OH ratio of the PUR was varied to 1.2, 1.4, and 1.6. The electrical conduction studied by measuring the dependence of current on the applied field and temperature. Electrical conductivity in PUR was expressed by Arrhenius relations and the activation energies were calculated. Moreover, hyperbolic sine function was used to determine the conduction mechanism in PUR. It's presumed that the conduction mechanism was assisted by ions for the PUR which were contributed by oleic acid due to dissociation of protons and highly polar urethane groups in PUR. Furthermore, the dielectric behaviors of the material have been measured at room temperature in the frequency range of 100 Hz to 40 MHz. The frequency‐dependent conductivity of PUR materials has been analyzed using a Jonscher's power law expression and the plot exhibits the typical behavior of ionic materials, i.e., the DC plateau and the frequency dependent region. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Thermal and dynamic mechanical characterization of polyurethane–urea–imide coatings

A series of NCO terminated polyurethane (PU)–imide copolymers were synthesized by a systematic three‐step process and were chain extended with different diol/diamine chain extenders. In the first step, isocyanate terminated PU prepolymers were prepared by reacting soft segments such as polyester (PE) polyols and polyether polyols such as polypropylene glycol (PPG‐1000) with hard segments like 2,4‐tolylene‐diisocyanate (TDI) or isophorone‐diisocyanate (IPDI) with NCO/OH ratio 2:1. In the second step, thermally stable heterocyclic imide ring was incorporated using isocyanate terminated PU prepolymers by reacting with pyromellitic dianhydride (PMDA) in a excess‐NCO:anhydride ratio of 1:0.5. The surplus NCO content after imidization was both moisture cured or partially reacted with chain extender and moisture cured. The films were characterized by thermogravimetric (TG), differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) instruments. The adhesion strength of these coatings on mild steel (MS), copper (Cu), and aluminum (Al) is dependent on the nature of the substrate. The TGA analysis show good thermal stability. The DMTA results show the microphase separation between the different hard and soft segments. Finally, a structure to property correlation was drawn based on the structure of the soft, hard, and chain extender and the observed properties are useful for understanding and design of intelligent coatings. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3158–3167, 2006     

聚酯型水性聚氨酯的合成和性能研究

以甲苯二异氰酸酯(TDI)、聚酯二元醇、二羟甲基丙酸等为主要原料合成了聚酯型水性聚氨酯乳液。研究了三羟甲基丙烷(TMP),二羟甲基丙酸(DMPA),异氰酸酯基与羟基物质的量比(n/n)等对水性聚氨酯耐水性能、稳定性以及力学性能等的影响。结果表明,当n/n为NCO OH NCO OH2,DMPA含量为6%,TMP加入量0.6%,水性聚氨酯性能最佳。     

NCO含量对水性聚氨酯乳液性能影响的研究

以自制聚酯多元醇和过量的2,4一甲苯二异氰酸酯为原料进行预聚反应,合成含异氰酸酯端基的预聚体,再以二羟甲基丙酸为亲水剂,引入二元醇进行扩链反应,制备了水性聚氨酯。研究了残留NCO含量及NCO／OH比值对乳液合成及性能的影响。研究认为控制NCO／OH比值在2．0～2．5之间,残留NCO含量在3．0％～3．5％之间时,制备的乳液性能最佳。     

Hyperbranched polyurethane (HBPU)-urea and HBPU-imide coatings: Effect of chain extender and NCO/OH ratio on their properties

Effect of chain extender and NCO/OH ratio on the properties of hyperbranched polyurethane (HBPU)-urea and HBPU-imide coatings were examined. The NCO terminated pre-polymers were prepared by reacting the first (G1) and the second (G2) generation hyperbranched polyester polyols (HBP-G1 and HBP-G2) with excess diisocyanate. The excess NCO content of the prepolymer was reacted with different chain extenders viz., 3-aminopropyl triethoxysilane (APTES), pyromellitic dianhydride (PMDA) and N-hydroxyphthalimide (NHTM) to obtain HBPU-urea or HBPU-imide coatings. The structure–property relationships of the different coatings were investigated by FTIR peak deconvolution, and these data suggests the highest extent of hydrogen bonding interaction for PMDA-based coatings, which increases with increasing NCO/OH ratio. Film properties were evaluated by TGA, DMTA, UTM and contact angle measurements; these results were supported by FTIR deconvolution results. As per contact angle measurements, hydrophobicity of coatings increased by increasing NCO/OH ratio. The adhesive strength, abrasion resistance, alkali resistance, and gel content of the coatings were also evaluated.     

大豆油-油酸多元醇改性聚氨酯胶黏剂及其性能研究

以环氧大豆油（ESBO）、油酸（OA）为主要原料,在无溶剂无催化剂的条件下合成了环氧大豆油-油酸多元醇（P-OA-ESBO）,通过红外（FT-IR）和核磁（1H-NMR）对环氧大豆油-油酸多元醇（P-OA-ESBO）的结构进行了表征。然后以P-OA-ESBO、异氟尔酮二异氰酸酯（IPDI）、甘油为主要原料在无催化剂条件下合成了环保型包装用聚氨酯胶黏剂。利用热重分析（TGA）、差示扫描量热法（DSC）、拉伸力学性能测试、PE/OPP复合膜的剥离强度测试及剪切强度测试考察了不同R（NCO/OH）比聚氨酯胶黏剂涂膜的耐热、机械和粘接性能。结果表明：大豆油-油酸多元醇成功改性聚氨酯胶黏剂,相比于传统的大豆油基多元醇改性聚氨酯,该方法更为绿色经济环保,且当R值为1.3-1.5时合成的聚氨酯胶黏剂的力学拉伸和剪切能较好,R值在1.7时合成的聚氨酯胶黏剂剥离强度较优异,可满足PE/OPP膜的基本复合要求。     

聚氨酯改性不饱和聚酯树脂的制备

利用二步法由二元醇、二元酸及TDI合成一种聚氨酯改性不饱和聚酯树脂,第一步由二元醇和二元酸合成以羟基封端的不饱和聚酯,第二步利用不饱和聚酯的—OH与TDI的—NCO反应合成聚氨酯改性不饱和聚酯,使得树脂分子链段上既有不饱和链节又含有聚氨酯基团,结合了聚氨酯涂料和不饱和聚酯涂料的优点,使其涂膜性能优异。试验发现TDI加入量为10%时效果最佳。     

FT-IR and XPS studies of polyurethane-urea-imide coatings

A series of polyurethane (PU)-urea-imide coatings were synthesized by a systematic three-step reaction process. Initially isocyanate terminated PU prepolymers were prepared by reacting soft segments such as polyester polyols (prepared from neopentyl glycol, adipic acid, isophathalic acid and trimethylol propane) or polyether polyols (polypropylene glycol-1000) with hard segments such as 2,4-toluene diisocyanate or isophorone diisocyanate with NCO/OH ratio of 2:1. Heterocyclic imide ring into the PU backbone was incorporated by co-polymerization with pyromellitic dianhydride (PMDA) from the excess NCO groups in the PU prepolymer with an NCO/anhydride ratio of 1:0.5 and the surplus NCO content after imidization was moisture cured. PU-urea-imide coatings were also obtained by partial chain extension of the excess NCO groups in the NCO terminated PU-imide copolymers, and the remaining excess NCO groups were completely reacted with atmospheric moisture. The obtained polymers were analyzed with Fourier transform-infrared (FT-IR) and angle resolved X-ray photoelectron spectroscopy (AR-XPS). The type and change in intermolecular H-bonding interaction in the PU-urea-imide films with structural variables was identified by deconvolution of the FT-IR spectra using Origin 6.0 software through Gaussian curve-fitting method. The FT-IR analyses of the PU-urea-imide coating films show dependence of phase separation on the nature of chain extender. Surface characterization data from AR-XPS suggests the dependence of phase segregation behaviour on the nature of the chain extender, which also supports the FT-IR observations.     

聚酯型阳离子水性聚氨酯乳液的合成研究

采用聚酯二醇(JW2503),甲苯二异氰酸酯(TDI),N-甲基二乙醇胺(MDEA)为基本原料,用丙酮法合成了聚酯型阳离子水性聚氨酯乳液。讨论了NCO／OH比值、MDEA的加入方式及其用量、反应温度等因素对乳液性能的影响。实验结果表明,当NCO／OH比值为2.7,MDEA的用量占树脂的6％-7％,且采用饥饿加料的方式滴加MDEA,初聚体合成温度为65℃,引入亲水扩链基团的扩链反应温度为40℃,中和度为90％-100％时合成的聚酯型阳离子水性聚氨酯乳液具有较好的贮存稳定性,且涂膜的耐水性和机械性能良好。     

Preparation of polyurethane wood adhesives by polyols formulated with polyester polyols based on castor oil

The aim of this work was the synthesis of polyester polyols from renewable sources as one of the important compounds of polymeric polyurethane (PU) adhesives. The polyester polyols were synthesized by condensation polymerization of different dicarboxylic acids with castor oil and the reaction conditions were in agreement with green chemistry principles. The preparation of PU wood adhesives was carried out by the reaction of each obtained polyester polyol with 4, 4′-diphenylmethane diisocyanate (MDI). The adhesive performance was improved by mixing the obtained polyester polyols with polypropylene glycol (PPG 400) and butanediol (BD). Different NCO/OH ratios were used to obtain adhesives with appropriate properties. The structures of the synthesized polyesters and adhesives were characterized by FTIR, thermogravimetric analysis (TGA) and lap shear strength values were also determined in various conditions such as cold water, hot water, acid and alkali solutions.     

Preparation and properties of polyurethane coatings based on acrylic polyols and trimer of isophorone diisocyanate

This paper presents a study on the effect of NCO/OH ratio and an increase in hydroxyl content of acrylic polyols on the properties of polyurethane (PU) coatings. Coating properties studied are gloss, scratch resistance, flexibility and adhesion, mechanical properties include tensile strength, modulus, percent elongation and Shore hardness, while physicochemical properties include chemical resistance and solvent absorption of coated PU samples. A series of acrylic polyols (copolymers) based on butyl acrylate (BA), methyl methacrylate (MMA), styrene and 2-hydroxy ethylacrylate (HEA) were prepared by selecting different percentage of hydroxyl content. Trimer of isophorone diisocyanate (IPDI) was also synthesized in the laboratory. This trimer has trifunctionality. Isocyanurate ring of trimer increases thermal properties of PU. Polyurethanes from these acrylic polyols (containing different percent hydroxyl) and trimer of IPDI were prepared with two different NCO/OH ratios viz, 1.1:1 and 1.2:1. Polyurethanes were coated on substrates for measuring coating properties. Mechanical properties were measured on cast films of the PUs. The experimental results revealed that all polyurethane coatings based on acrylic polyols and IPDI trimer showed good gloss, scratch resistance and excellent adhesion. Thermal stability of these PU samples was found to be better. Physicochemical properties reflected that these PU have excellent chemical and solvent resistance.     

人造麂皮用聚氨酯涂层剂的合成

以聚酯二醇、二苯基甲烷二异氰酸酯、扩链剂已二醇等为原料合成了人造麂皮用聚氨酯涂层剂,讨论了NCO与OH基团的摩尔比（即R值）对聚氨酯溶液粘度及其膜的物理性能的影响。结果表明,R愈近于1,溶液的粘度愈大,所合成的聚氨酯的分子量愈高,膜的物理性能愈高。     

Fully biobased polyester polyols derived from renewable resources toward preparation of polyurethane and their application for coatings

Renewable resources such as isosorbide and dimer acid were used to prepare fully biobased polyester polyols and polyurethane (PU) coatings. The structural features of polyester polyols were studied by end-group analysis and spectroscopic methods. Then polyols were utilized in the preparation of PU coatings by reacting with diisocyanate. The prepared PU coatings were tested for both mechanical and chemical testings, which involved gloss, cross-cut adhesion, pencil hardness, anticorrosion performance by immersion and Tafel plot methods, and chemical resistance against water, solvent, and acid media. The prepared PUs were also tested for their thermal stability using a thermogravimetric analyzer and surface morphology by a scanning electron microscopy. Tested mechanical properties, chemical resistance, and thermal stability results demonstrated that the renewable sources used in the preparation of PU coatings can be good substitutes over petroleum resources. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47558.     

单组分聚氨酯乳液制备及其结构与性能研究

采用预聚合法,以聚酯二元醇(PEA)、甲苯二异氰酸酯(TDI)、二羟甲基丙酸(DMPA)为基本原料合成了分子链上带有亲水基团(-COOH)的聚氯酯预聚体。以特殊的水化方式制得聚酯型水性聚氨酯乳液。讨论了温度、-NCO-与-OH的物质的量之比(R)、亲水基团含量、合成工艺分别对材料力学性能、耐水性、玻璃化转变温度(Tg)等的影响。研究发现,采用前中和工艺、在高速搅拦下将预聚物加入到水中的水化方式,当R值为1．2,羧基含量为1．6％时,合成的聚酯型水性聚氨酯乳液具有较好的贮存稳定性,且涂膜的耐水性和力学性能良好。     

Characterization of polyurethane foam prepared by using starch as polyol

Polyurethane foams were prepared using starch as a main component of polyols and their structural, mechanical, and absorbing properties for organic solvents were investigated. Fourier transform infrared spectra showed that urethane linkage was formed by the reactions between ? NCO of diisocyanates and ? OH of polyols. When polyurethane foams were prepared at high molar ratio of ? NCO/? OH, the unreacted ? NCO groups were detected. Also, urea linkage was formed by the reaction between diisocyanate and water, which was used as the foaming agent. The micrographs showed that the polyurethane foams had closed‐cell structure, of which the cell size increased with ? NCO/? OH molar ratio. The density of polyurethane foams increased with molecular weight of polyethylene glycol. The compressive moduli of polyurethane foams increased with ? NCO/? OH molar ratio. Polyurethane foams prepared using toluene‐2,4‐diisocyanate as diisocyanate had the highest modulus, while those prepared using hexamethylene diisocyanate had the lowest modulus. In case of the absorbency for the organic solvents, the polyurethane foams prepared at ? NCO/? OH molar ratio of 0.8 had the maximum absorbency. Among several organic solvents, the absorbency for dimethyl sulfoxide was the highest, while the absorbency for tetrahydrofuran was the lowest. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1544–1553, 2007     

Degradable polyurethane based on star-shaped polyester polyols (trimethylolpropane and ɛ-caprolactone) for marine antifouling

The star-shaped polyester polyols based on initiators (trimethylolpropane or pentaerythritol) and ɛ-caprolactone were prepared by polycondensation reaction. The degradable polyurethane (PU) films were prepared by mixing star-shaped polyester polyols and crosslinker agent (hexamethylene diisocyanate trimer). The hydrolytic degradation and water absorption experiments demonstrated that the PU films could erode in artificial sea water, which were controlled by varying the ratios of ɛ-caprolactone/trimethylolpropane and the arm number of star-shaped polyester polyols. The mechanical properties of PU films and coatings increased with decreasing the ratios of ɛ-caprolactone/trimethylolpropane and increasing the arm number of star-shaped polyester polyols. The surfaces of PU films and coatings kept eroding, which were revealed by scanning electron microscopy. The copper ion release rates from PU coatings reached steady state at about 31 days. The marine field tests of PU coatings demonstrated that the degradable PU coatings based on star-shaped polyester polyols were effective coatings for marine antifouling.     

Polyurethane–urea anionomer dispersions. I

Polyurethane–urea anionomer dispersions with different stoichiometric DMPA/polyol and NCO/OH ratios were preapred from poly(oxypropylene)glycol, toluene diisocyanate (TDI), dimethylolpropionic acid (DMPA), and ethylenediamine (EDA). The dispersion-cast films were prepared and characterized by mechanical properties, dynamic mechanical analysis (DMA), and differential scanning calorimetry (DSC). Increasing the hard-segment content by either increasing the DMPA/polyol or the NCO/OH ratios affects the glass transition temperature (T_g) of the soft segments. © 1994 John Wiley & Sons, Inc.