Novel Protocol for Resole Phenol Formaldehyde Resins Synthesis with Tubular Reactor and Characterization

Abstract

A novel strategy has been established, in the laboratory scale, for the generation of the popular thermosetting resin phenol formaldehyde (PF; resole), through a continuous process using a tubular reactor, which is usually developed in the commercial scale through a batch process. A refractive index technique is employed to evaluate the optimum residence time within the tubular reactor to obtain a commercial grade equivalent of PF resin. The unreacted free formaldehyde level has been found to be very low in the resole resin prepared by using the new route. The initial characterization of the resin has been done through Fourier transform infrared spectroscopy and gel permeation chromatography. The cure characteristics of the resin have been analyzed through differential scanning calorimetry. The degradation features of the cured resole are investigated using a thermo gravimetric analyzer and the fractured surfaces are analyzed through scanning electron microscopy. It has been confirmed that the adverse effects of a batch reactor process can be significantly reduced by adopting a continuous resin manufacturing process for PF resin which can be successfully extended to commercialization after optimization.

Fourier transform infra-red spectroscopy to determine formaldehyde to phenol ratio of phenol formaldehyde resole

“…In order to validate the applicability of the different model, five different types of PF resoles were synthesized according to the previous literature. 24,25 The formulation and intrinsic properties of resultant PF resole are given in Table 1. Among them, four samples were synthesized through a continuous process while a resole was made through a batch process.…”

Synthesis, Characterization, and Thermal Pyrolysis Mechanism of Resorcinol‐Formaldehyde Resin‐Containing Phenylboronic Acid

“…[24] The gelation time, which refers to the time required for the resin to transform into a three-dimensional cross-linked structure, is an indication of the curing rate and molecular reactivity of the resins. [17,25] Compared to RR, it was observed that the gel times of RR modified with phenylboronic acid decreased with increasing PBA content and free formaldehyde content. A shorter gel time implies that the cross-linking reactions of the resin occur more rapidly.…”

“…To determine the total solid content, ≈2 g of the resin sample was weighed and placed in an oven at 378 K for 3 h. After 3 h, the sample was removed from the oven and allowed to cool to room temperature and reweighed. [2,17] Each resin sample was analyzed four times, and the mean value was used to calculate the total solid content using Equation (2) below Total solid content ð%Þ ¼…”

“…The standard deviation of the gelation time is AE 0.12. [17][18][19][20][21] 2.3.5. Viscosity Rheological analysis refers to the study of the flow and deformation of a material under the application of external forces and can be used to analyze the processability of resins.…”

Enhanced Electrical Properties and Impact Strength of Phenolic Formaldehyde Resin Using Silanized Graphene and Ionic Liquid

“…Because it is an outstanding flame retardant with good adhesion, high heat resistance, excellent mechanical properties, and straightforward processability, phenolic formaldehyde (PF) resin has been extensively used in a number of applications, including coatings, construction, transportation, electronics, and the automotive and aerospace industries. − However, its intrinsically low electrical conductivity and high brittleness have limited its widespread use in other fields. − Thus, in recent years, electrically conductive polymer composites have attracted considerable attention due to their lightweight, corrosion resistance, and easy processing.…”