Jatin R. Thakkar

Glass-reinforced Vinyl Ester Resin Composites:

The curing behaviour of vinyl ester resin, the condensation product of acrylic acid with diglycidyl ether of bisphenol-A, was studied by differential scanning calorimetry. The glass-fibre-reinforced composites of the vinyl ester resin were prepared and evaluated for their chemical, electrical and mechanical properties. The incorporation of styrene during the curing of the vinyl ester resin showed significant improvements in tensile strength and dielectric properties.

Kinetic study on the effect of addition of epoxy diluents and/or fortifier on the curing characteristics of DGEBA by differential scanning calorimetry

Abstract The effects of the addition of diluents and/or fortifier (PGEHA), synthesized by condensing phenylglycidyl ether (PGE) and 4-hydroxy acetanilide (HA) using 0.1 wt % diethylamine hydrochloride as catalyst, on the epoxy resin have been investigated kinetically by differential scanning calorimetry. The rate of reaction was followed dynamically over the range 25–300°C. The activation energy for the various epoxy systems, as determined using four different computational methods, is in the range of 51–97 kJ mol−1 and the order of the reaction is ~ 2.0.

Novel vinyl ester resin and its urethane derivatives for glass reinforced composites

The paper describes glass-fibre-reinforced composites of a vinyl ester resin derived from triglycidyl-m-aminophenol and its urethane derivatives. The fabricated laminates were characterized by their mechanical properties and chemical resistance. The incorporation of vinyl monomer styrene in the resin system was found to improve some properties of composites remarkably. Aus Triglycidyl-m-aminophenol wurde ein neues Vinylester-Harz hergestellt und mit Diisocyanaten zu Urethanen derivatisiert. Aus diesen Harzen hergestellte glasfaserverstarkte Komposite wurden hinsichtlich ihrer mechanischen Eigenschaften und Chemikalienbestandigkeit untersucht. Durch Polymerisation in Gegenwart von Styrol werden die Eigenschaften merklich verbessert.

Epoxy resins-polyamide coating system

Abstract Bisester namely 1,1′-(1-methyl ethylidene) bis[4-{1-(1-imino-4-ethyl benzoate)-2-propa-nolyloxy}] benzene was synthesized by the reaction of epoxy resin (DGEBA) and 4-aminoethyl benzoate (4-AEB) using triethyl amine as catalyst. The synthesized bisester was reacted with three different aliphatic diamines viz; diethylene triamine (DETA), triethylene tetramine (TETA) and polyethylene amine (PEA) to obtained respective poly-amide resins (PAs) abbreviated as DGEBA-4-AEB: DETA, DGEBA-4-AEB: TETA and DGEBA-4-AEB : PEA respectively. The PAs synthesized were used as a curing agent for the difunctional epoxy resin (DGEBA) and trifunctional epoxy resin (TGPAP) in three different ratios. Using triethyl amine as a catalyst and PAs as a curing agent, DGEBA and TGPAP were polymerized on mild steel panels at 120[ddot]C for 1 hr. The coated panel thus obtained were tested for scratch hardness, flexibility, impact strength and chemical resistancy. It appears from the results for the epoxy resins, epoxy based poly...

Epoxy Resin Based Polyamides as Epoxy Curing Agents

Abstract Novel bis ester 1,1′-(1-methyl ethylidene) bis[4-{1-(1-imino-4-ethyl benzoate)-2-pro-panolyloxy}] benzene was prepared by the reaction of epoxy resin, diglycidyl ether of bisphenol-A (DGEBA) and 4-aminoethyl benzoate. The polyamides (PAs) were prepared by the condensation of this novel bis ester with three aliphatic diamines viz; diethylene triamine (DETA), triethylene tetramine (TETA) and polyethylene amine (PEA). The resultant PAs were characterised by infrared spectroscopy (IR). The number average molecular weight (MBn) was estimated by non-aqueous conductometric titration. As produced, polyamides may act as epoxy curing agent, the kinetic study of the PA-epoxy resin system has been established by differential scanning calorimetry (DSC) and the kinetic parameters have been evaluated. Neat PA-epoxy cured products have also been characterized by thermogravimetric analysis (TGA). The glass fiber reinforced composites of the produced PA-epoxy system have been fabricated and were characterized by F...

Novel epoxy based polyamides-I

Abstract Novel epoxy resin based polyamides (EPAs) were prepared by the condensation of bisester derivative namely 1,l′-(1-methylethylidene) bis[4-{1-(1-imino-3-ethylbenzoate)-2-propanolyloxy}]benzene, (BE) with various aliphatic diamines viz., 1,2-ethylene diamine (EDA), 1,3-propylene diamine (PDA), 1,4-butylene diamine (BDA) and 1,6-hexamethylene diamine (HMDA). The resultant EPAs were characterized by infrared spectroscopy (IR) and number average molecular weight ( Mn ) of EPAs were estimated by non-aqueous conductometric titration. As produced, EPAs having amido groups may act for curing of epoxy resins. Differential scanning calorimetric (DSC) curing kinetics of the epoxy resins viz., diglycidyl ether of bisphenol-A (DGEBA) and triglycidyl ether of p-amino phenol (TGPAP) have been investigated using EPAs as a curing agent and triethyl amine (TEA) as a catalyst. Thermal stability of the cured epoxy systems were studied by thermogravimetric analysis (TGA).

Study on Novel Polyamides Based on Ester Terminated Epoxy Resin

The bisester 1, 1′-(1-methylethylidene)bis[4-{1-imino-4-ethylbenzoate-2-propanolyloxy}]benzene (DGEBA-4-AEB), synthesized by the reaction of the epoxy resin diglycidyl ether of bisphenol-A (DGEBA) with 4-amino ethyl benzoate (4-AEB), was condensed with different aromatic diamines, namely 4, 4′-diamino diphenyl methane (DDM), 4, 4′-diamino diphenyl sulfone (DDS) and benzidine (Ben) to yield novel epoxy based curing agents. The resultant novel epoxy based polyamides (PAs) were characterized by infrared spectroscopy along with the estimation of number average molecular weight (Mn ) by gel permeation chromatography (GPC). Using differential scanning calorimetry (DSC), the kinetics of the curing reactions of PAs–epoxy resin systems were established by evaluating the usual kinetic parameters. The thermal behaviour of PAs–epoxy cured products was also studied by thermogravimetric analysis (TGA).

Coating Properties of Di- and Tri-functional Epoxy Resin Using Novel Epoxy Based Polyamide as Curing Agent

Abstract Bis ester namely 1, 1′-(1-methylethylidene) bis[4-{1-(1-imino-4-ethyl benzoate)-2-pro-panolyloxy}]benzene was synthesized by the reaction of epoxy resin, diglycidyl ether of bisphenol-A-(DGEBA) and 4-amino ethyl benzoate (4-AEB) using triethyl amine as catalyst. The synthesized bisester was reacted with two different aliphatic diamines viz., 1. 4-butylene diamine (BDA) and 1. 6-hexamethylene diamine (HMDA) to obtain respective polyamide resins (PAs) abbreviated as DGEBA-4-AEB:BDA and DGEBA-4AEB:HMDA respectively. The PAs synthesized were used as a curing agent for the difunctional epoxy resin, (DGEBA) and trifunctional epoxy resin, (TGPAP) in three different ratios. Using triethylamine as a catalyst and PAs as a curing agent. DGEBA and TGPAP were polymerized on mild steel panels at 120°C for 1 hr. The coated panels thus obtained were tested for scratch hardness, flexibility, impact strength and chemical resistancy. It appears from the results that epoxy resins, DGEBA based polyamides can successf...

Studies of vinyl ester resins and their urethanized derivatives

The epoxy resins diglycidyl ether of bisphenol A and triglycidyl p-amino phenol were reacted with acrylic acid to afford the corresponding acrylated resins. These vinyl ester resins were then reacted with toluene di-isocyanate to procure their urethanized derivatives. All these resins were characterized by their viscosity, number average molecular weight and infrared spectrophotometry. Curingconditions for these resins were established by differential scanning calorimetry. The results indicated that the curing reaction follows first-order kinetics, with activation energy in the range 53-84 kJ mol-. Styrene monomer was observed to lower the curing temperature of all resin systems when incorporated prior to curing.

Novel Metal Complex Based Epoxy Resin

Abstract The novel metal complex synthesized by the condensation reaction of metal chloride (NiCl2) with schiff base and hydroquinone (in 1:1:3 mole ratio) was epoxidized in presence of base catalyst to obtain metal complex based epoxy resin (i.e., Ni-epoxy). An attempt has been made to carry out comparative curing study (by DSC) for Ni-epoxy, diglycidylether of bisphenol-A (DGEBA) and triglycidylether of p-amino phenol (TGPAP) resin system using aliphatic and aromatic diamines as catalyst. On the basis of curing characteristics the mild steel panels were coated using all the three resins. The coated panels were tested for their flexibility, scratch hardness, impact strength and chemical resistancy.