Properties and curing kinetics of C21-based reactive polyamides as epoxy-curing agents derived from tung oil

Abstract

Three C 21 -based reactive polyamides were synthesized from tung oil and different polyamines. The thermal and mechanical properties of cured products of the C 21 -based polyamides and diglycidyl ether of bisphenol A (DGEBA) were investigated. It was found that the cured materials were superior to those cured by C 36 -based polyamides in tensile strength and flexural strength and had a better flexural modulus. The glass transition temperatures of the three cured C 21 -based polyamides, determined by differential scanning calorimetry (DSC), were found to be 108, 109 and 116 1C, which were also higher than those of C 36 -based polyamides. The curing kinetics of C 21 -based polyamides in the presence of DGEBA were studied by nonisothermal DSC at different heating rates. The kinetic parameters of the curing process were determined by the iso-conversional method given by Má lek. A two-parameter (m, n) autocatalytic model (the Š está k-Berggren equation) was found to be the most suitable to describe the curing kinetics of the studied curing agents. The activation energy (E a ) values of the three curing agents with DGEBA are dependent on the amine values of polyamides. The E a value of the curing reaction decreased as the primary amine values of curing agents increased. The experimental non-isothermal DSC curves show a good agreement with theoretical calculations.

Synthesis and Application of a Cationic Polyamine as Yankee Dryer Coating Agent for the Tissue Paper-Making Process

“…In this case, the temperature of the yankee where the product was proven exceeded 100 • C and it can be seen in Figure 6 that the T g of the coating alone and emulsified with release in a proportion similar to that used in the yankee were 85.7 and 77.7 • C, in which the polymer behaves like a thermoplastic rubber and is soft enough to produce high quality paper [31]. This DSC behavior was similar to other polyamide-based resins as reported by Huang K. et al [32]. It should be noted that each yankee operates at different temperatures depending on the requirements of the paper mill.…”

A renewable tung oil-derived nitrile rubber and its potential use in epoxy-toughening modifiers

“…Similar results have been obtained in previous studies, in which rubber and other oil-based polymers have been used to toughen the epoxy resin. 12,21,26 The increased viscosity may restrict the movement of reaction groups and then reduce the enthalpy. Fig.…”

“…40 Compared with other tung oil-based products synthesized by the Diels-Alder reaction, whose elongation-at-break is less than 5%, E-CTMAs show higher toughness. 21,23,24 However, an increase in the content of CTMA decreases the tensile strength and Young's modulus. Because the addition of CTMA reduces the cross-linking density and enhances ductility, the modied samples are less sensitive to deformation; this leads to lower Young's modulus.…”

“…By the Diels-Alder reaction, a number of tung oil-derived toughened epoxy resins have been produced. [21][22][23][24] As is well-known, the products obtained via the Diels-Alder reaction contain a ring structure, which may reduce the toughening effect. Hence, to avoid the formation of a ring structure, an alternative strategy is to synthesize the tung oilbased toughener via radical polymerization; however, only few studies have been reported on the synthesis of an epoxy resin toughener by the radical polymerization of tung oil or tung oilderives.…”

Synthesis and Characterization of Ricinoleamide‐Based Polyurethane

“…They have several excellent properties that can be utilized for the preparation of a number of valueadded polymers and other materials that have found various applications in different fields. A variety of vegetable oils such as Linseed, Tung, Soybean, Sunflower, Karanj, Castor, etc., have been used for this purpose [3,4].…”