November 22, 2021

Water-based Alkyd Resin Coatings

Due to the easy availability and low price of raw materials for alkyd resin coatings, and the excellent gloss, flexibility, and adhesion of the coating film, it has become one of the most researched and produced in the coating industry. However, traditional alkyd resin coatings have low film hardness, However, traditional alkyd resin coatings suffer from low film hardness, poor water, and heat resistance, and their application does not meet the high-performance requirements of industrial development, so it is imperative to modify them to broaden the application area of alkyd resin coatings. The current research on the modification of alkyd resin coatings is mainly in two aspects: resin modification and color filler modification. Resin modification is done by introducing other groups into the resin molecular chain, or by blending with polyurethane, acrylic, epoxy, and silicone resins. The main purpose of color filler modification is to add different functional color fillers to improve the performance of alkyd resin coatings. The performance of alkyd resin coatings. Some progress has been made in these aspects. In this paper, we focus on the latest research on the modification of several waterborne alkyd resin coatings. In this paper, we focus on the latest research on the modification of several waterborne alkyd coatings.

1.1 Resin modification study of aqueous alkyd coatings

1.1 Gutter oil-based modified aqueous alkyd resins

Guo Liqin [14] of Southwest University of Science and Technology prepared a gutter oil-based waterborne alkyd resin using gutter oil, phthalic anhydride (PA), and pentaerythritol as the main raw materials and lithium hydroxide as the catalyst. The coating performance test results show that the epoxy resin modification, gloss is poor. When the oil level was 40% to 50%, the excess amount of alcohol was 20% to 35%, the acid value at the end of the reaction was 60 to 70 mgKOH/g, m (triethylamine): theoretical amount = 1.75:1, w (drying agent) = 5%, the volatile organic compound (VOC) of the acrylic modified paint was only 30 g/L, the drying speed was significantly improved, and the water and saltwater resistance met the requirements. This method opens up an important way for the utilization of gutter oil.

1.2 Degradation of waste polyethylene terephthalate (PET) bottles Preparation of aqueous alkyd resin from pepper seed oil

Lei Rui et al. from Shaanxi University of Science and Technology used waste PET bottles, trimethylolpropane (TMP), and other materials to prepare water-based alkyd resin for pepper seed oil.

(TMP) and non-edible pepper seed oil (ZSO) as the main raw materials. A PET modified pepper seed oil aqueous alkyd resin was prepared by Lei Rui et al. A water-based alkyd resin with PET modified pepper seed oil was prepared using N, N-dimethylethanolamine as a neutralizer. The performance of the coating showed that when the excess alcohol was 11.5%, the oil content was 50%, w (PET) = 9.3%, w (DMPA) = 3.5%, and w (PET) = 3.5%. The coating has good storage stability, water resistance, hardness, and thermal stability compared with normal aqueous alkyd when the alcohol content is 11.5%, the oil level is 50%, w (PET) = 9.3%, and w (DMPA) = 10%.

1.3 Linseed oil-based self-drying aqueous alkyd resin

After alcoholysis at 240℃ for 1h, benzoic acid (HA) and o-phthalic anhydride (PA) were added at a lower temperature to obtain a small molecule of alkyd resin. Then, a linseed oil-based self-drying aqueous alkyd resin was prepared by adding aqueous trimellitic anhydride (TMA) at a temperature of 160-170°C and the esterification reaction was carried out until the acid value was satisfactory. The performance test results of the resin showed that when the oiliness = 50%, the excess amount of alcohol is 6%, the acid value of the resin before neutralization is 50-60mgKOH/g, and the mass fraction of ethylene glycol butyl ether (BCS) is 10%, the gloss of the coating film is 94, the hardness is H, the drying time is 6h, and the water-resistance time is 360h.

1.4 GMA modified waterborne alkyd resin

Ltd. Li Zhiqin et al. used lithium hydroxide as the catalyst and allowed the alcoholysis reaction of soybean oil and TMP to occur at 240°C. The endpoint of the alcoholysis reaction was reached when the tolerance of ethanol was 5. Then, PA, EC240, and benzoic acid (HA) were added, and TMA was fully esterified. After the acid value was passed, TEA, a partial neutralizer, and glycidyl methacrylate (GMA), a modifier, were added at a lower temperature. The performance test results show that when w (GMA) = 1.0%, the storage stability is 180d without change, the surface drying time is 45min, the flexibility is 1mm, the seawater resistance is 12d, the impact strength is 50kg/cm, the salt spray resistance is 2000h, and it can be used in marine engineering, port terminal, and ocean transportation.

1.5 Epoxy resin-modified waterborne alkyd resin

Yang Tang et al. of Nanjing University of Science and Technology used TMP, linseed oil, and epoxy resin (E-44) as the main raw materials and dibutyltin dilaurate (DBTDL) as the catalyst to alcoholize the resin at 220°C for 0.5h, then lowered the temperature to 180°C and added DEG, IPA, and HA. When the acid value reached 10 mgKO/g, maleic anhydride (MA) and TMA were added, and propylene glycol methyl ether (PM) and neutralizer TEA were added after sufficient reaction to prepare an epoxy-modified aqueous alkyd resin. The results of the film performance tests showed that when w(E-44) = 7%-10%, the acid value before neutralization was 55-65 mgKOH/g, the curing conditions: temperature of 120°C and time of 30 min, the aqueous amino alkyd resin film prepared with this film-forming agent had an adhesion of class 1, hardness of 2H, resistance to 5% NaCl1 by mass for 5 d, and impact strength of 50 %. 5d, the impact strength of 50kg/cm, and good anti-corrosion effect on steel materials transported by sea.

1.6 Hydroxyacrylic acid resin modified with water-soluble alkyd resin

A water-soluble alkyd resin modified by hydroxy acrylic acid resin was prepared by adding PA esterification reaction with TMA as aqueous monomer and high solid content hydroxy acrylic acid resin as the modifier. The results of structural characterization and performance tests showed that the coating surface drying time was 20 min at 50%-60% w (hydroxy acrylic acid resin), and the water, aging, and saltwater resistance were significantly improved compared with unmodified.

1.7 Epoxy resin/acrylic acid modified waterborne alkyd resin

The base alkyd resin was prepared by adding linolenic acid (LA), epoxy resin E-44, and triphenyl phosphorus (PPh3) as the catalyst to obtain epoxy resin. After distillation of the solvent, an epoxy/propionic acid-modified aqueous alkyd resin was prepared using styrene (St) as the hard monomer, butyl acrylate (BA) and methyl methacrylate (MMA) as the soft monomers, acrylic acid (AA) as the acidic monomer, BPO as the initiator, and TEA as the neutralizer. The results show that when w (acrylic acid) = 7%, w (E-44) = 9%-14%, the end-point acid value is 40-50 mgKOH/g, and the neutralization degree is 80%, the resin has good water solubility, the coating film hardness is H, the adhesion is 0, and the water-resistance time is more than 24h.

1.8 Waterborne acrylic emulsion/waterborne alkyd resin hybrid coating

The waterborne alkyd resin was firstly prepared by Yu Guoliang of Nanyang Agricultural Vocational College with soybean oil, NPG, PA, MA, HA, TMP, and TMA as the main raw materials, and then the waterborne alkyd resin was cold-mixed with waterborne acrylic emulsion HG-100, RICOH H98 was selected as the anti-flash agent, and Wanxia S-144-0 was used as the drying agent. A waterborne acrylic emulsion/waterborne alkyd resin hybrid coating was prepared by using homemade aqueous alkyd resin and aqueous acrylic emulsion HG-100 as a cold blend, Rico H98 as an anti-flash agent, and Wanxia S-144-0 as a drying agent. The performance test results showed that when w(HG-100) = 20%, w(S-1440) = 1.4%, w(Su425) = 0.2%, w(H98) = 0.6%, the coating had good storage stability, 60° gloss was 92; surface drying time was 10min; actual drying time was 4h. Water resistance

Time is 180h.

1.9 mussel-like adhesive protein (PHEA-DOPA) / GMA modified water-based alkyd coating mussel foot filaments can secrete a strong adhesive capacity of mussel adhesive protein (MAP), firmly adhered to the bottom of the ship and the rock surface.

The main component of MAP is dopa (DOPA).

Based on the principle of molecular bionics, Yang Mingliang of Harbin Engineering University introduced DOPA structure into the polymer by ammonolysis reaction using dopamine hydrochloride (DOP) and polysuccinimide (PSI) as the main raw materials to produce a polymer compound similar to mussel adhesion protein (PHEA-DOPA). The film properties were investigated before and after modification with GMA modified aqueous alkyd resin. The results showed that the double bond oxidation crosslinking point increased after the modification of glycidyl acrylate, and the drying and water resistance properties were significantly improved. The performance is improved.

1.10 Silicone acrylate polyurethane modified waterborne alkyd anti-corrosion coating

   Shanghai Qipeng Engineering New Material Technology Co., Ltd. Peng Fu De firstly prepared alkyd resin by esterification reaction with tall oil fatty acid (TOFA), pentaerythritol, and PA as main raw materials, and then added emulsifier AE300 to obtain water emulsion alkyd dispersion. Hydrophilic polyurethane prepolymer was produced by reacting dehydrated diol (Po1-756), isophorone diisocyanate (IPDI), and aqueous monomer dihydroxy methyl propionic acid (DMPA) as raw materials. TEA was used as a neutralizer, and acrylate monomer, emulsifier, silane coupling agent, initiator, and chain extender were added to obtain silicone polyurethane emulsion. A silicone acrylate polyurethane modified aqueous alkyd coating was formulated with aqueous alkyd dispersions and silicone polyurethane emulsions as the main film-formers. The results show that when m (silicone polyurethane emulsion):m (alkyd emulsion) = 1:1, the film has a bending test of 1mm, hardness of H, adhesion of grade 1, water-resistance of 250h, artificial aging resistance of 600h, resistance to 3% (mass fraction) NaCl solution and salt spray resistance of 250h, and can be applied to concrete substrates and steel structures. 2.2 Nanomaterial modification study of water-based alkyd resin coating

2.1 Nano silicon/Polyphenylamine/Oxidized Graphene Modified Waterborne Coatings

  The unique two-dimensional layer structure and size effect of graphene provide excellent hydrophobicity, corrosion resistance, and electrical conductivity. Graphene, polydopamine, conductive polyaniline, and nano-silica were modified by Yang Ning of the University of Chinese Academy of Sciences to obtain several different nano-compounds, which were used as fillers and aqueous alkyd resins as film-formers to prepare a graphene-based nanomaterial modified aqueous coating. The results showed that the polyphenylamine-graphene oxide bonding was stable and the best performance was obtained at 25℃ for 18h. When compounded with polydopamine, m (polydopamine):m (polyaniline-graphene oxide) = 2:1, the nano-sheeted button-shaped projections enhanced the barrier effect and hydrophobic effect, and significantly improved the corrosion resistance of the aqueous alkyd varnish. When compounded with nano-silica, m (nano-silica):m (polyaniline-graphene oxide) = 1:4, a three-dimensional barrier structure is formed, which significantly improves the corrosion resistance of aqueous alkyd varnishes.

2.2 Isocyanate-functionalized graphene/alkyd anti-corrosion coatings

Ma Hengyi [25] prepared an isocyanate-functionalized graphene/alkyd anti-corrosion coating by using isophorone diisocyanate (IPDI) as the modifier and hydrazine hydrate as the reducing agent and then using IPDI-modified graphene (IMG) as the filler and oil-based alkyd resin (AR) as the film-forming material. The results showed that when the preparation conditions were 80°C, 8h, m(GO):m(IPDI) = 1:8, the modified graphene had increased oleophilic, showing a thin layer of yarn, and good thermal stability. When w(IMG) = 0.5%, IMG was uniformly dispersed in the alkyd resin, and the adhesion of the coating was grade 1, hardness was 4H, impact strength was 90kg/cm, and salt spray resistance was 480h.

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