New Method to Evaluate the Crosslinking Degree of Resin Finishing Agent with Cellulose Using Kjeldahl Method and Arrhenius Formula

Abstract

In anti-wrinkle finishing, the crosslinking degree of fabric is mainly determined by wrinkle recovery angle, stiffness, and viscosity, these indicators can only reflect the finishing effect from a macro perspective, which cannot reflect whether the crosslinking is sufficient, and it is difficult to quantify the crosslinking degree. In this paper, we combined the Kjeldahl method with the Arrhenius formula and proposed a method to analyze the crosslinking degree of dimethyloldihydroxyethyleneurea (two-dimensional (2D) resin) with cotton cellulose during delayed-cure finishing for the first time. The nitrogen content of completed fabrics during storage was measured by the Kjeldahl method, and the reaction rate equation of the 2D resin and cellulose under normal temperature conditions was calculated. The results show that the nitrogen content is more suitable to indicate the crosslinking degree, and the apparent activation energy was 28.271 kJ/mol and the pre-finger factor was 0.622, which indicated that the 2D resin was prone to cross-linking with cotton fabrics during storage. During long-term storage, the relative errors between the calculated and measured values of the nitrogen content were within ±5%, and the accuracy was higher than the traditional evaluation method. The stability of 2D resins during the storage of delayed-curing finishing was also analyzed through this method.

Evaluation of Storage Stability for Delayed-Curing Non-Iron Finishing Sensitized Fabrics via Characteristic Group and Cross-linking Reaction Kinetics

“…The untreated sample was used as a blank test, and the experiment was repeated three times. The aldehyde group content (mmol/g fabric) of untreated cotton fabrics was negligible and was calculated according to equation (2):…”

“…Nitrogen Content of Sensitized Fabric (Kjeldahl Method). The samples were ultrasonically washed with deionized water of pH = 10 for 20 min (to remove the unreacted 2D resin), dried naturally, and equilibrated in a standard environment for 24 h. 2 The nitrogen content of the finished fabric was determined according to the procedure of Ma et al with slight modification; 0.5 g sample was accurately weighed, cut into pieces, and transferred into 500 mL nitrogen bottle; 0.2 g copper sulfate, 6 g potassium sulfate, and 20 mL concentrated sulfuric acid were added to the bottle and transferred to the nitrification furnace for nitration. After the sample was completely nitrated, the solution was blue-green and continued heated for 0.5 h. The nitrogen bottle was removed, transferred to the Kjeldahl nitrogen analyzer for distillation after cooling, and the produced gas was absorbed with 0.2% boric acid.…”

“…Antiwrinkle (non-iron) finishing is necessary for the reduction of the sliding between cotton fiber molecular chains, improvement of the fiber resilience, and the shape and size stabilization of the cotton fabric during washing and wearing. [1][2][3] This process includes the impregnation of cotton fabric with a finishing solution composed of cross-linking agents (non-iron finishing agents), catalysts, and so on, and cross-linking occurs between cellulose and the finishing agent under high-temperature curing. However, the flat planeness of the cotton fabric from conventional non-iron finishing has an effect on its actual application.…”

Chemical Components of Fungus Comb from Indo-Malayan Termite Macrotermes gilvus Hagen Mound and Its Bioactivity against Wood-Staining Fungi

“…First was a proximate analysis, continuing by determining the amino-acid content, extractive-substance contents, and determining the chemical content of selected extracts. Proximate analysis was performed using the standard methods outlined by some Indonesian national standards (SNI) to determine crude fat (SNI 2891-1992 point 8.1), total ash (SNI 01-3709-1995 point 6.3), acid-insoluble ash (SNI 01-3709-1995 point 6.4), crude fiber (SNI 2891-1992), and carbohydrate (SNI 2891-1992 point 9.5) levels of the fungus comb, while Kjeldahl's methods were used to determine crude protein content [29]. The amino-acid content was determined using high-performance liquid chromatography (HPLC).…”

The Use of the ATD Technique to Measure the Gelation Time of Epoxy Resins

“…Large volumes of mixtures can lead to local overheating of the composite and the introduction of internal stresses, which, in extreme cases, lead to cracking of the casting [32][33][34]. The control of the curing temperature significantly influences the cross-linking rate, which is described by the Arrhenius law, where lowering the temperature by 10 • C causes a two-fold decrease in cross-linking rate [35][36][37][38]. In an industrial condition, measuring the rise in temperature is more important than measuring the overall thermal effect of a reaction.…”