**1. Introduction**

As we know, thickeners can be used to improve fluid viscosity and fluid rheology [1,2]. Adding a small amount of thickener to the required thickening system can significantly increase the apparent viscosity of the system. At present, thickeners are widely used in oil exploitation [3], agriculture [4], food processing [5], daily chemical products [6], textile printing and dyeing [7], the pharmaceutical industry, and other fields [8–11]. With the development of industry, the variety of thickeners is gradually increasing, among which cellulose [12] and polyacrylic acid thickeners [8] are the most widely used. At present, with the thickener market being well established, domestic and foreign researchers have begun to devote themselves to the research of various modified thickeners.

Valeria et al. [13] reported a study on the rheological properties of polymer chains hydrophobically modified with a small amount of N, N-dialkyl acrylamide (N, N-dihexylacrylamide (DHAM) and N, N-dioctylacrylamide (DOAM)). Chang-E Zhou et al. [14] prepared an associative thickener by compounding two polyacrylate-based copolymers—cationic starch and polyacrylic acid—mediated by polyethylene glycol and a polyacrylamide crosslinker, which were used for digital printing of nylon carpet with enhanced performance. Abdelrahman et al. [15] reported that the thickener of biodegradable poly (lactic acid-methacrylic acid)-crosslinked

**Citation:** Chen, X.; Huang, W.; He, B.; Zhang, Y. Synthesis and Application of Tackifying Dispersant Poly (Vinyl Alcohol-Acrylic Acid-Triallyl Cyanate). *Polymers* **2022**, *14*, 557. https://doi. org/10.3390/polym14030557

Academic Editors: Wei Wu, Hao-Yang Mi, Chongxing Huang, Hui Zhao and Tao Liu

Received: 13 December 2021 Accepted: 20 January 2022 Published: 29 January 2022

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**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

<sup>1</sup> College of Chemistry, Sichuan University, Chengdu 610065, China; cxyyyazj@163.com (X.C.); euihsm5029739@163.com (W.H.)

polymer hydrogel was formulated in situ via a one-pot reaction employing polycondensation of lactic acid and methacrylic acid followed by free radical polymerization with N, N-methylene diacrylamide crosslinker. Tao Guan et al. [16] reported a polymerizable acrylic-type hydrophobically modified ethoxylated urethane (HEUR), which was end-functionalized by the reactive methacrylate group and hydrophobic octadecyl tail to significantly improve the viscoelastic behavior of waterborne systems such as coatings and inks.

This modified thickener has a remarkable thickening effect; however, due to the variety of raw materials, high price, and complex synthesis steps, its commercial application value is greatly limited. Meanwhile, researchers are rarely involved in the application of modified thickeners [17]. For example, applications in wearable and implantable conductive textile materials have increased in recent years [18–20], one method of which is preparing the graphene (Gr) finished onto the surface of the fabric via multiple impregnation [20,21]. However, the surface of Gr lacks groups that form a good combination with textile materials, showing the poor adhesion between Gr and the matrix, along with weak physical fastness, seriously affecting the product quality [22]. Therefore, in order to improve Gr-Gr and Gr-fabric adhesion, as well as enhance the conductivity, thickener and dispersant should generally be added to graphene slurry [23], while the addition of a dispersant (such as alkyl diphenyl ether sulfonate, naphthalene sulfonic acid condensate, etc.) will affect the flexibility of the fabric. Therefore, in this paper, from the perspective of reducing the use of dispersant while improving the adhesion of Gr, a modified tackifying dispersant was synthesized, which can not only maintain the thickening performance, but also effectively disperse Gr.
