Polyesteramide Urethane Research Articles

Corrosion inhibition potentials of Cucurbita polyesteramide urethane on mild steel in hydrochloric acid medium: Experimental and computational studies

Polyesteramide urethane was synthesized from Cucurbita maxima seed oil and characterized via Thermogravimetric analysis, Fourier Transformed Infrared spectroscopy, and Differential Scanning Calorimetry. The inhibiting effect of the synthesized polyesteramide urethane (CPEAU) on mild steel in 1.0 Molar concentrations of HCl was investigated through electrochemical and weight loss measurements. The temperature effect on the corrosion performance of the mild steel with or without CPEAU was studied in the range of 303–333 K. It was found that an increase in temperature led to a decrease in inhibition efficiency. The adsorption of CPEAU molecules on mild steel was spontaneous and the isotherm model which the adsorption obeyed was Langmuir's. It was observed that, the value of activation energy for the uninhibited test solution (35.82 kJ/mol) was discovered to be less than those obtained for the inhibited test solutions at different temperatures (49.91 kJ/mol, 50.49 kJ/mol, 53.78 kJ/mol, 62.78 kJ/mol and 69.89 kJ/mol), that signifying electrostatic interaction (physisorption mechanism) of CPEAU on mild steel. Potentiodynamic polarization investigation signified a mixed-type inhibition mechanism of CPEAU at a lower concentration with predominant cathodic effects at a higher concentration. Quantum chemical descriptors revealed the carboxylic group on CPEAU molecule as the active adsorptive sites through which adsorption occurred on the mild steel surface, and a molecular dynamics simulation showed the adsorption and binding energies of the inhibitor. The experimental and computational results were in good agreement.

Anti-microbial and anti-corrosive poly (ester amide urethane) siloxane modified ZnO hybrid coatings from Thevetia peruviana seed oil

The utilization of renewable resources for the development of organic coatings is a viable means of creating alternatives to petroleum-based chemicals which are not eco-friendly. This paper reports the synthesis of polyesteramide–urethane–silica–zinc oxide hybrid coatings from Thevetia peruviana seed oil (TPSO). The periphery of ZnO nano-particles is modified with 3-aminopropyltrimethoxysilane to prepare silica grafted ZnO composite particles. The TPSO based polyesteramide was reacted with 4,4′-diisocyanatodicyclohexylmethane in presence of siloxane modified ZnO to obtain –NCO terminated polyesteramide–urethane–silica ZnO prepolymer. These hybrid pre-polymers were casted on tin foil and cured under atmospheric moisture to obtain eco-friendly, moisture cured polyesteramide–urethanes–silica–zinc oxide hybrid coating films. The synthesized polyester and polyurethane formation was confirmed by using FT-IR and NMR spectroscopic techniques. The resultant hybrid coating films were characterized by using FT-IR, TGA, DSC, SEM, corrosion resistance and microbial resistance. Results confirm that with increase of siloxane modified ZnO content in the polyurethane matrix thermal stability, glass transition temperature and corrosion resistance improved. The antibacterial activity shows that the hybrid films exhibit excellent resistance towards Escherichia coli and Staphylococcus aureus. The salt spray test on coated panel samples show good corrosion resistance properties.

Comparative study of polyaniline and poly(1‐naphthylamine) dispersed oil polyurethane coatings

PurposeThe purpose of this paper is to report a comparative study of conducting polymer (CP) dispersed oil polyurethane coatings derived from a sustainable resource, i.e. polyaniline (PANI)/coconut oil polyesteramide urethane (CPEAU) and poly(1‐naphthylamine) (PNA)/linseed oil polyurethane (LPUA) coatings.Design/methodology/approachThe coatings were prepared chemically and were characterized for their physico‐chemical, physico‐mechanical, corrosion protective efficiency, and open circuit potential measurements. The morphological analysis of the corroded carbon steel (CS), coated uncorroded CS, and coated corroded CS specimens, was carried out by SEM analysis.FindingsThe study revealed that the presence of a CP enhanced the corrosion protective efficiency of the sustainable resource‐based organic coatings. The type of CP used also played a major role in defining the corrosion resistance behavior of the coating materials.Originality/valueThe comparative study of anticorrosive properties of CP with oil‐based polyurethane blends has been studied for the first time.

Poly (urethane fatty amide) resin from linseed oil—A renewable resource

Poly (urethane fatty amide) [PULFA] resin was synthesized by using a one-shot technique at room temperature from diol linseed fatty amide [DLFA; a monomer obtained from the aminolysis of renewable resource, such as linseed oil with diethanolamine and sodium methoxide used as a catalyst], 1.0 moles, and varying ratio of toluylene-2,4(6)-diisocyanate [TDI, 0.08–1.5 moles] in minimum amount of xylene without any chain extender and catalyst. In this process phthalic acid/anhydride which is normally used in the synthesis of polyesteramide was completely replaced by TDI as in case of uralkyd. The reaction mechanism of the same has been discussed here. The mode of reaction and structure of the resin was confirmed by physico-chemical tests and spectral analysis. The performance of the coatings on mild steel strips was tested by physico-mechanical and chemical/corrosion resistance tests. Thermo gravimetric analysis [TGA] and differential scanning calorimetry [DSC] techniques were used to investigate the thermal stability and curing behavior of the resin. The aforementioned properties of newly synthesized resin were compared with those of reported linseed oil-based polyesteramide urethane [Ur-LPEA, synthesized by partial replacement of phthalic anhydride by TDI] and uralkyd. The newly synthesized resin has shown improved physico-mechanical and corrosion resistance performance to Ur-LPEA and alkyd, whereas to those of uralkyd has comparable results. The PULFA resin exhibits not only superior properties to some of the reported resins, but also helps in the conservation of energy by being synthesized at room temperature as compared to other similar reported systems which were synthesized at reasonably high temperatures. The present study reveals that the PULFA resin can be used as a substitute to Ur-LPEA, alkyd and uralkyd in the field of corrosion protective paints and coatings.

Development of a Sustainable Resource Based Conducting Composite of Polyaniline‐Poly(esteramideurethane)

Polymers synthesized from coconut oil as a precursor find scarce applications. Polyesteramide urethane synthesized from coconut oil, a natural resource, is a dough‐like material, unusable in our study. Upon loading with polyaniline it becomes tough and flexible. Composites of ClO4 − doped polyaniline with coconut oil based poly(esteramide urethane) (CPEAU) were prepared by a solution blending technique, using different ratios of polyaniline(2 wt%, 4 wt% and 8 wt%). The composites were further characterized by FT‐IR, DSC, TGA, XRD, and SEM. Conductivity was found to be in the range 2.5×10−5−5.7×10−4 S cm−1. The composite was found to show weak hydrogen bonding interactions between PANI and CPEAU at 8 wt% loading.

Urethane modified boron filled polyesteramide: a novel anti-microbial polymer from a sustainable resource

Boron filled soybean oil based polyesteramide (BPEA) was synthesized. It was further modified through a reaction with tolylene-2,4-di-isocyanate (TDI) to obtain boron filled polyesteramide urethane (BPEAU) with different loadings of urethane. The structures of BPEA and BPEAU polymers were confirmed by FT-IR, 1H NMR and 13C NMR spectroscopies. The physico-chemical characterization, viz., hydroxyl value, iodine value, acid value, refractive index and inherent viscosity was carried out by standard methods. Anti-bacterial and anti-fungal activities of these polymers were investigated by the measurement of the size and clarity of the zone of inhibition in nutrient media. All compositions of BPEAU resin were found to inhibit microbial growth while the resin with 8% urethane loading (BPEAU-8) showed the highest anti-microbial activity. The BPEAU resin can, therefore, be used as an anti-fungal and anti-bacterial coating material.