Syntheses of novel photosensitive polysiloxanes and their effects on properties of UV-cured epoxy methacrylate coatings

Two UV-curable polysiloxanes—side methacryloxy group polysiloxanes (MAPS) —were successfully synthesized through a two-step reaction. Two series of various percentages of these synthesized MAPS were then cured with bisphenol-A epoxy methacrylate (BEMA) via UV radiation to obtain cured coatings. We found that the additive MAPS improved the thermal stability of the cured coatings. It not only reduced the surface energy of the coatings, but also significantly affected the other properties, including gloss, flexibility, and water resistance. Compared to the phase separation between BEMA and MAPS-1 with lower volume of methacryloxy groups, MAPS-2 with higher volume of methacryloxy groups dispersed uniformly in BEMA, thereby provding good performances for such coating materials.     

Synthesis of cationic UV‐curable methacrylate copolymers and properties of the cured films of their composites with alicyclic epoxy resin

Cationic UV‐curable methacrylate copolymers consisting of glycidyl methacrylate, iso‐butyl methacrylate, and 2,2,3,4,4,4‐hexafluorobutyl methacrylate were synthesized, and their structures were characterized by FTIR, ¹H NMR, and ¹³C NMR. A series of UV‐cured composite films based on the synthesized copolymers and an alicyclic epoxy resin, 3,4‐epoxycyclohexylmethyl‐3,4‐epoxycyclohexanecarboxylate (CE) were obtained through photopolymerization. Their surface contact angle, chemical ability, gloss, light transmittance, thermal behavior, micromorphology, and shrinkage were investigated. Results indicated that these cured resins showed excellent gloss and visible light transmittance; after the combination of the copolymers and CE, and in the presence of fluorine in the curing systems they exhibited relatively fine water resistance, chemical, and thermal stability. It was observed that these copolymers could decrease the degree of the volume shrinkage to CE. The UV‐curable materials may have promising applications in optical fiber coatings, flip chip and Organic Light‐Emitting Diode (OLED) packing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Flexibility improvement of epoxy resin by using polysiloxanes and their derivatives

A study of increasing the flexibility and lowering the internal stress of the cured epoxy resing was carried out by using polysiloxanes capped with functional groups and premaking polysiloxane particles with d = 1.1 μm and narrow distribution. Polysiloxanes capped with functional groups were prepared by the reaction of X-22-163B with bisphenol-A, hexanedioic acid, and decanedioic acid. Poly(dimethylsiloxane-b-arylester) was synthesized by the reaction of poly(dimethylsiloxane) (X-22-162C) with arylester oligomers. Polysiloxane particles were obtained by cycling the mixture of polysiloxanes containing a vinyl group and a?Si–H group, respectively, emulsifier, and water in homogenizer. When oily polysiloxanes were used to improve the flexibility of epoxy resin, good compatibility of polysiloxanes with epoxy resion, and high molecular weight capped with epoxy group favor the formation of small-sized particles and homogeneous dispersion in the cured matrix. Comparisons were made among the epoxy resing modified with oily polysiloxanes capped with different functional groups. The results indicate that lightly crosslinked polysiloxane particles with d = 1.1 μm and narrow distribution have the greatest increase of elongation and biggest decrease of internal stress. The reason for this is discussed. © 1994 John Wiley & Sons, Inc.     

Synthesis and characterization of poly(methyl methacrylate)/polysiloxane composites and their coating properties

A series of poly(methyl methacrylate) (PMMA)/polysiloxane composites and their coatings were prepared as designed. A copolymer (PMMAVTEOS) containing methyl methacrylate (MMA) and vinyltriethoxysilane (VTEOS) was prepared by free radical polymerization and then condensed with methyl triethoxysilane (MTES) to fabricate PMMA/polysiloxane composites; their corresponding coatings were obtained via a curing process in an oven (at 75 °C). The polymers were characterized by gel permeation chromatography and Fourier transform infrared spectroscopy. The surface property, hardness, water contact angle, thermal stability, and optical property of the coatings were investigated by scanning electron microscopy, pencil hardness testing, water contact angle testing, thermogravimetric analysis, and ultraviolet–visible spectroscopy, respectively. The results showed that, after addition of MMA, the pencil hardness of the coatings was reduced from 6H to 2H and the thermal stability decreased from 365 to 314 °C. However, it increased the flexibility and adhesion properties (the water contact angle increased from 94.7° to 102.1°). The transparent PMMA/polysiloxane coatings showed excellent scratch resistance, a smooth surface, high thermal stability, and a strong adhesion property. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46358.     

Synthesis of bio-based unsaturated polyester resins and their application in waterborne UV-curable coatings

In this paper, three bio-based unsaturated polyesters were synthesized from itaconic acid and different diols which could be derived from renewable resources. Their chemical structures were confirmed by FT-IR, ¹H NMR and acid value as well as hydroxyl value. Waterborne UV curable networks based on these polyesters were manufactured and their mechanical properties, thermal stability and coating properties including pencil hardness, flexibility, adhesion, water resistance and solvent resistance were investigated. Results showed that the UV-cured polyester coatings exhibited high hardness, good water resistance and solvent resistance. The coatings reported in this paper combined the merits of bio-based materials, UV-curing process and water distribution.     

Synthesis of fluorinated/methacrylated epoxy based oligomers and investigation of its performance in the UV curable hybrid coatings

Organic–inorganic hybrid coatings based on fluorinated/methacrylated soybean oil and bisphenol A/F epoxy methacrylate were obtained by combining photopolymerization and sol–gel process. Hard and transparent hybrid coatings were prepared on polycarbonate panels and their physical and mechanical properties such as gel content, hardness, adhesion, gloss, contact angle as well as tensile strength were measured. Results from the mechanical measurements showed that the properties of hybrid coatings improved with the increase in fluorine and sol–gel precursor contents. Thermo gravimetric analysis results demonstrated that fluorine and silica incorporations significantly enhanced the thermal oxidative stability of the hybrid coating materials. The surface morphology was also characterized by scanning electron microscopy (SEM). SEM studies indicated that inorganic particles were dispersed homogenously throughout the organic matrix.     

High performance moisture cured poly(ether–urethane) amide coatings based on renewable resource (cottonseed oil)

In this investigation, polyetheramide resin was prepared through the condensation polymerization of N,N-bis (2-hydroxyethyl) cottonseed oil fatty amide (HECOFA) with bisphenol-A. It was further modified by 2,4-toluene diisocyanate (TDI) in 10–30 wt% of polyetheramide to develop a series of moisture curing urethane-modified polyetheramide resins (UMCOPEtA). The synthesized resin was characterized using ¹H NMR, ¹³C NMR, FTIR and solubility in various organic solvents at room temperature. The thermal and curing behavior of the resin was investigated using thermogravimetric analysis and differential scanning calorimetric techniques. The physico-chemical properties such as hydroxyl value, iodine value, specific gravity and mechanical properties like scratch hardness, impact, and flexibility were determined by standard laboratory methods. Coatings of UMCOPEtA resin were prepared on mild steel panels to evaluate chemical resistance performance against acid, alkali, water and xylene. The newly developed UMCOPEtA coatings showed improved hardness, impact, gloss, water and chemical resistance when compared with unmodified polyetheramide coatings, and thus were found to be suitable as a high performance coating material.     

含氟嵌段丙烯酸酯聚合物/环氧树脂自分层涂料的制备与性能

利用引发剂连续再生催化剂原子转移自由基聚合(ICAR-ATRP)合成了一系列结构可控的含有含氟丙烯酸酯和甲基丙烯酸缩水甘油酯(GMA)的两嵌段丙烯酸酯聚合物,即聚(甲基丙烯酸丁酯-co-甲基丙烯酸缩水甘油酯)-b-聚甲基丙烯酸十二氟庚酯[P(BMA-co-GMA)-b-PDFHMA,BGF]。将嵌段聚合物与环氧树脂混合制备自分层涂料。傅里叶变换红外光谱(FT-IR)和扫描电子显微镜-能谱分析仪(SEM-EDS)测试表明,当两嵌段聚合物中P(BMA)-co-GMA与PDFHMA的相对分子质量分别为5 300和2 300、GMA结构单元相对分子质量占总相对分子质量的20%,且BGF用量为10%时,漆膜固化过程中含氟嵌段聚合物可以部分迁移到漆膜表面,共混漆膜氟元素自迁移效果较好,表层氟含量达到20%以上,且增加含氟树脂中GMA含量时漆膜氟元素迁移效果下降;耐紫外老化性测试结果表明,含氟树脂的加入使得漆膜的光泽保持率更好,耐黄变性变化不大;水接触角和耐盐雾性测试结果表明,相对纯环氧树脂,加入10%含氟嵌段聚合物使漆膜的水接触角均提高到了100°以上,自分层漆膜的耐盐雾性都有一定提高,可以有效防止漆膜的起泡。嵌段聚合物的加入量低于4%时,对漆膜的基本力学性能没有影响,但光泽有一定下降。     

Alkyd–epoxy blends as multipurpose coatings

The alkyd resins of three different compositions based on nahar seed oil (Mesua ferrea), phthalic anhydride, and maleic anhydride were synthesized by an alcoholysis method. These alkyd resins were blended with a commercially available epoxy resin (Araldite 250, Ciba Geigy, Mumbai, India) separately to study the performance of the blends as coatings. The morphology of the blends was studied with scanning electron microscopy. The drying time, gloss, flexibility, pencil hardness, adhesion, pressure test, and chemical resistance under different conditions were measured for this purpose. The thermal characteristics of the blends were also investigated by thermogravimetric analysis. The studies showed better performance of the blends with respect to the drying time, hardness, flexibility, gloss, pressure test, thermal stability, and chemical resistance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 516–521, 2006     

Studies on urethane‐modified alumina‐filled polyesteramide anticorrosive coatings cured at ambient temperature

Coatings prepared from polyesteramide resin synthesized from linseed oil, a renewable resource, have been found to show improved physicomechanical and anticorrosive characteristics. These properties are further improved when aluminum is incorporated in the polyesteramide resin. The coatings of this resin are generally obtained by baking at elevated temperatures. With a view toward the use of linseed oil, as a precursor for the synthesis of polyesteramide resins and to cure their coatings at ambient temperature, toluylene diisocyanate (TDI) was incorporated into polyesteramide and alumina‐filled polyesteramide in varying proportions to obtain urethane‐modified resins. The latter resins were found to cure at room temperature. The broad structural features of the urethane‐modified polyesteramide and alumina‐filled polyesteramide were confirmed by FTIR and ¹H–NMR spectroscopies. Scratch hardness; impact resistance; bending resistance; specular gloss; and resistance to acid, alkali, and organic solvents of the coatings of these resins were determined by standard methods. Physicomechanical and anticorrosive properties, specular gloss, and thermal stability of the urethane‐modified alumina‐filled polyesteramide coatings were found to be at higher levels among these resins. It was found that TDI could be incorporated in polyesteramide up to only 6 wt %, such that above this loading its properties started to deteriorate, whereas alumina‐filled polyesteramide could take up to 10 wt % TDI. Explanation is provided for the increase in scratch hardness and impact resistance above 6 and 10 wt % addition of TDI in polyesteramide and alumina‐filled polyesteramide, respectively, as well as for the decrease in flexibility and resistance to solvents, acid, and alkali of coatings of these resins above these limits of TDI addition. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1855–1865, 2001     

Synthesis,characterization, and performance evaluation of hard,anticorrosive coating materials derived from diglycidyl ether of bisphenol A acrylates and methacrylates

Diglycidyl ether of bisphenol A acrylate (DAC) and diglycidyl ether of bisphenol A methacrylate (DMAC) were synthesized by the reaction of an epoxy [diglycidyl ether of bisphenol A (DGEBA)] with acrylic acid and methacrylic acid, respectively. The synthesized resins were characterized by determination of the acid, hydroxyl, and saponification values. Structure elucidation was done by gel permeation chromatography, Fourier transform infrared spectroscopy, ¹H‐NMR spectroscopy, and ¹³C‐NMR spectroscopy. DACs were cured with melamine formaldehyde resin at low pH values. The pH of the resin systems was adjusted with phosphoric acid. The coatings of these systems were formed on mild steel specimens for physicomechanical and chemical/corrosion‐resistance performance. The coatings of DAC and DMAC showed excellent scratch hardness and good impact‐resistance performance. The coatings of DMAC showed better performance than DAC with respect to chemical and corrosion resistance. Thermogravimetric analysis and differential scanning calorimetry were used to investigate the thermal stability and curing behavior of these systems. DAC showed a little higher glass‐transition temperature than DMAC and also showed a higher thermal resistivity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 494–501, 2005     

Surface properties of the epoxy resin modified by a novel functional fluorinated oligomer

A novel dicarboxyl-terminated poly(2,2,3,4,4,4-hexafluorobutyl acrylate) oligomer (CTHFA) was synthesized through metal-free anionic polymerization and hydrolysis reaction. Chemical structures of CTHFA were characterized by gel permeation chromatography and ¹H NMR. Two types of CTHFA with different chain lengths were initially used as an efficient surface modifier to improve the surface properties of epoxy resin, at the content of CTHFA ranging between 0 and 8 wt%. We minimized the amounts of the CTHFA used to achieve a high hydrophobic surface that was not obviously affected by the thermal properties of the epoxy resin. Surface properties and surface composition of the designed fluorinated epoxy resin were investigated by the contact angle and X-ray photoelectron spectroscopy (XPS). Modified epoxy resin with 5 wt% CTHFA containing longer chain length showed excellent hydrophobic surface properties (a high water contact angle about 115° and low surface energy 14.12?mN/m²) while the modified epoxy resin with 5 wt% CTHFA containing shorter chain length did not. XPS analyses indicated that the 5 wt% of fluorinated CTHFA epoxy resin with long macromolecular-chain enhanced more fluorinated groups?? migration to the surface than the fluorinated CTHFA-modified epoxy resin with short macromolecular-chain at the same content. Moreover, thermal properties of CTHFA-modified epoxy resin were also investigated.     

Synthesis and characterization of comb polycarboxylic acid dispersants for coatings

Comb polycarboxylic acid dispersants (CPCADs) graft acrylic copolymers which consist of hanging methoxy polyethylene glycol chains and carboxylic acid groups on main acrylic chain. The CPCADs have been synthesized by radical polymerization of methacrylic acid and methoxy polyethylene glycol methacrylate as a nonionic unsaturated hydrophilic macromonomer. The CPCADs are polymeric surfactants that can be used as anionic dispersant. Methoxy polyethylene glycol methacrylate has been synthesized by esterification of methacrylic acid and methoxy polyethylene glycol in the presence of methanesulfonic acid as catalyst. These have been characterized with ¹H‐NMR and GPC. Acid values of CPCA dispersants have been determined. The dispersion of CPCA dispersants depends on their molecular weights, length mPEG, and acid values. Dispersion of titanium dioxide in typical solvent‐based paint formulation has been investigated. The physicochemical and mechanical properties of surface coatings having CPCADs such as gloss, hardness, and contrast ratio have been investigated. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Organic–inorganic hybrid coatings prepared from glycidyl carbamate resin, 3-aminopropyl trimethoxy silane and tetraethoxyorthosilicate

Hybrid sol–gel coatings were formulated from glycidyl carbamate (GC) resins, 3-aminopropyltrimethoxy silane (APTMS) and tetraethoxyorthosilicate (TEOS) as the inorganic network former. GC and silane-modified GC resins were synthesized and then characterized using Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance Spectrometry (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). The resins were crosslinked with amine crosslinkers such as p-aminocyclohexyl methane (PACM), Ancamide 2050, Ancamide 2353 and Epikure 3164 at 1:1 equivalent ratio of the epoxy groups in the synthesized resin and amine crosslinker. The TEOS content in the coatings were varied to understand its effect on the coating properties. The hybrid coatings were cured at room temperature and humidity for more than 20 days as well as oven cured at 80 °C for 1 h. The thermal properties of the post-cured hybrid materials were evaluated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Mechanical property evaluation such as König pendulum hardness measurement, impact resistance and crosshatch adhesion tests of the post-cured samples were carried out. MEK double rub resistance and water contact angle of the coatings were also evaluated. All of the coatings had good adhesion to aluminum 2024-T3 and had good MEK double rub resistance, indicating good crosslinking. Properties such as T_g, hardness and flexibility varied with the amine crosslinker used with Epikure 3164 yielding the lowest T_g, highest flexibility, and lower hardness coatings. Increasing the amount of TEOS modification in the formulations increased the hardness, the T_g, and the thermal stability. The flexibility – determined using reverse impact measurements – also increased with increasing TEOS content.     

Design,synthesis, characterization,and aging properties of a new end-capped three-dimensional high-refractive index hybrid organic–inorganic polysiloxane

The actual need for hybrid organic–inorganic polysiloxanes is very high due to their importance in optoelectronic applications, especially for the preparation of anti- and low-reflection layers, photopatterned overcoats, flexible hard coats, and glass and metal coatings. However, such three-dimensional hybrid polysiloxanes have very often a limited shelf life and aged very rapidly. Consequently, this type of polymer may require to be stored at cold temperatures and needs to be dilute in organic solvent to a very low solid content, which are unprofitable conditions for commercialization purposes. Therefore, there is an urgent demand to prepare three-dimensional polysiloxanes, which are more resistant toward aging processes. Herein, a new hybrid three-dimensional polysiloxane has been designed and synthesized from three different silane precursors using the sol–gel technology, and characterized using gel permeation chromatography, ¹H, ¹³C, and ²⁹Si nuclear magnetic resonance and MS spectroscopies. One-fourth of the silanol groups present in the polysiloxane have been protected with chlorotrimethylsilane. The refractive index of the silicon wafer coated with the new polysiloxane was found to be 1.53, which is higher compare to traditional values. Importantly, the new protected three-dimensional polysiloxane did not age after being stored at T = 40°C for 3 weeks.     

含氟自交联型醋酸乙烯酯聚合物乳液的制备及表面性能

通过无皂乳液聚合法合成了一种含氟自交联醋酸乙烯酯聚合物,用表面电子能谱仪(ESCA)检测了树脂成膜后的含氟成分的分布情况,测量了涂膜与水、乙二醇的接触角,并应用该聚合物制作了一种氟碳涂料,检测了涂膜的耐冲击性、附着力、柔韧性、硬度、光泽度等常规性能和耐蚀、耐候性能。研究发现,含氟自交联醋酸乙烯酯聚合物成膜时产生了较大取向作用,含氟基团向空气/聚合物界面伸展,对聚合物内部分子形成了很好的保护作用,使涂膜具有较高的防腐性能及优异的耐候、耐蚀性能。相对于纯醋酸乙烯酯聚合物,当氟含量为5.73%时,涂膜光泽度达98.2%,硬度2H,附着力1级,柔韧性1级,耐冲击性50 cm,表面能由0.3751 mN·cm^-1降低到0.1652 mN·cm^-1;经人工气候老化1600 h,涂膜的光泽保留率大于93%;经化学介质浸蚀360 h后,涂膜外观无变化。     

Synthesis and application of novel UV-curable hyperbranched methacrylates from renewable natural tannic acid

With a view to developing high performance UV curable coatings with high renewable contents, acrylated epoxidized soybean oil (AESO) was combined with a novel kind of biorenewable tannic acid-based hyperbranched methacrylates (TAHAs). The TAHAs were synthesized by ring-opening reaction of glycidyl methacrylate (GMA), glycidyl ester of Versatic acid (CE10) and natural tannic acid (TA). The epoxy groups of GMA and CE10 were involved in the ring-opening reaction with the hydroxyl groups of TA while residual methacrylate groups can carry out photopolymerization. By controlling the ratio of GMA and CE10, TAHAs with varying degree of methacrylate groups have been prepared. The synthesized TAHAs were formulated into acrylated epoxidized soybean oil (AESO) based UV curable coatings to produce the biorenewable materials based UV curable coatings. The effects of TAHAs on AESO coated film properties of pendulum hardness, flexibility and adhesion were investigated. Mechanical properties, thermal properties and biodegradability of the cured films were also evaluated. With the incorporation of TAHAs, the hardness, adhesion, tensile strength of the cured coating films were remarkably improved, which were attributed to the unique structure of hyperbranched methacrylates. Meanwhile, the biorenewable content was not greatly decreased due to the biorenewable character of tannic acid in TAHAs. These results showed that TAHAs as efficient toughening agents could produce UV-curable coatings of balanced coating performance with reasonably high biorenewable content. Moreover, the environment degradability of AESO-based cured films was also enhanced after the addition of TAHAs.     

Synthesis and properties of novel fluorinated poly(arylene ether)s

Dibromomethylene‐containing monomer with a tetrafluorobenzene central unit was synthesized using 2,3,5,6‐tetrafluoro‐1,4‐bis(4‐methylphenoxy)benzene as a starting material. This approach enabled preparation of several fluorinated poly(arylene ether)s containing isomeric fragments, with or without allyl or acetyl side groups, which were prepared by interaction of the synthesized tetrafluorobenzene‐based monomer with various types of hydroxyl‐substituted diphenyl ethers. The structure of the synthesized compounds was determined using Fourier transform infrared, ¹H NMR and ¹⁹ F NMR spectroscopy techniques. Most of the resulting polyethers were soluble in chlorinated, ether‐type or polar amide solvents. The molecular weight, mechanical and thermal properties of the synthesized fluorinated poly(arylene ether)s were studied depending on the inherent isomery of macromolecular chains and the nature of functional groups. Some ways of functionalization of the prepared fluorinated polyethers with epoxy and triethoxysilyl groups were proposed. © 2015 Society of Chemical Industry     

Synthesis and application of acrylic colloidal unimolecular polymers as a melamine thermoset system

Acrylic polymers were synthesized with a ratio of 1 : 7 or 1 : 8 of acrylic acid to acrylic ester monomers to produce an acid‐rich resin. The polymers were water reduced and solvent was stripped to produce colloidal unimolecular polymers (CUPs). These particles were typically 3–9 nm in diameter depending on the molecular weight. They were then formulated into a clear coating with melamine as the crosslinker with thermal curing. Compared to commercial latex films, these melamine‐cured acrylic CUPs had a distinct advantage of having a near‐zero volatile organic compound, better availability of surface functional groups , and improved water resistance. The coatings were evaluated for their methyl ethyl ketone resistance, adhesion, hardness, gloss, flexibility, abrasion , and impact resistance properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40916.     

Water‐borne melamine–formaldehyde‐cured epoxy–acrylate corrosion resistant coatings

Organic protective coatings are widely used in corrosion control. However, environmental standards establish that the volatile organic compounds either must be removed or controlled at the lowest possible levels. The carcinogenic environmental impact of volatile organic compounds has led to the substitution of solvent‐borne coatings by water‐borne coating systems. Among recently developed water‐borne coatings, epoxy‐ and acrylic‐based coatings have a special significance over other reported water‐borne systems. Keeping in mind, the importance of water‐borne coatings in the present work, we report the synthesis of water‐borne epoxy–acrylate (EpAc) and melamine–formaldehyde (MF) as well as formulation of their anticorrosive coatings. The structural elucidation of MF‐cured EpAc was carried out by FTIR, ¹H NMR, and ¹³C NMR spectroscopic techniques. The coatings of EpAc‐MF were applied on mild steel strips and were evaluated for physicochemical, physicomechanical characterization, and the anticorrosive performance under different environmental conditions. The present coating system EpAc coatings exhibited superior performance as compared to the reported water‐borne epoxy–acrylatecoatings. The presence of melamine–formaldehyde in the resin increases the scratch hardness, impact resistance, alkali resistance, and thermal stability of these coatings. EpAc‐MF‐1 was found to cure at ambient temperature and exhibit good physicomechanical properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008