Development of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride cross-linked carboxymethyl cellulose films

Liu

ACS Appl. Mater. Interfaces

et al. 2020

140

107

Stimulus-responsive hydrogels, such as conductive hydrogels and thermoresponsive hydrogels, have been explored extensively and are considered promising candidates for smart materials such as wearable devices and artificial muscles. However, most of the existing studies on stimulus-responsive hydrogels have mainly focused on their single stimulus-responsive property and have not explored multistimulus-responsive or multifunction properties. Although some works involved multifunctionality, the prepared hydrogels were incompatible. In this work, a multistimulus-responsive and multifunctional hydrogel system (carboxymethyl cellulose/poly acrylic-acrylamide) with good elasticity, superior flexibility, and stable conductivity was prepared. The prepared hydrogel not only showed excellent human motion detection and physiological signal response but also possessed the ability to respond to environmental temperature changes. By integrating a conductive hydrogel with a thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) hydrogel to form a bilayer hydrogel, the prepared bilayer also functioned as two kinds of actuators owing to the different degrees of swelling and shrinking under different thermal stimuli. Furthermore, the different thermochromic properties of each layer in the bilayer hydrogel endowed the hydrogel with a thermoresponsive “smart” feature, the ability to display and conceal information. Therefore, the prepared hydrogel system has excellent prospects as a smart material in different applications, such as ionic skin, smart info-window, and soft robotics.

Section: Results and Discussionmentioning

confidence: 94%

Multiple-Stimuli-Responsive and Cellulose Conductive Ionic Hydrogel for Smart Wearable Devices and Thermal Actuators

Liu

ACS Appl. Mater. Interfaces

et al. 2020

140

107

“…A gradual switch to biobased plastics has been witnessed by the increasing use at an industrial level of alternative raw materials [10,11] such as polylactic acid (PLA) [12], polybutyl succinate (PBS) [13,14], polyhydroxyalkanoate (PHA) [15][16][17], and polyethylene furanoate (PEF) [18][19][20], together with different composite materials produced from starch [21][22][23][24], CMC [25][26][27][28][29][30], wood [31,32], lignin [33,34], and many different agro-industrial wastes [35][36][37].…”

Section: Introductionmentioning

confidence: 99%

Recent Advancements in Plastic Packaging Recycling: A Mini-Review

et al. 2021

Self Cite

Today, the scientific community is facing crucial challenges in delivering a healthier world for future generations. Among these, the quest for circular and sustainable approaches for plastic recycling is one of the most demanding for several reasons. Indeed, the massive use of plastic materials over the last century has generated large amounts of long-lasting waste, which, for much time, has not been object of adequate recovery and disposal politics. Most of this waste is generated by packaging materials. Nevertheless, in the last decade, a new trend imposed by environmental concerns brought this topic under the magnifying glass, as testified by the increasing number of related publications. Several methods have been proposed for the recycling of polymeric plastic materials based on chemical or mechanical methods. A panorama of the most promising studies related to the recycling of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and polystyrene (PS) is given within this review.

“…In this prospective, quaternary ammonium salts of 2-halo-4,6-dialkoxy-1,3,5-triazines, e.g., 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM(Cl)), (see Figure 2), represent a valid alternative for the formation of amide bonds both in organic and water solvent [20,21,[32][33][34][35][36][37][38][39]. In the last years, DMTMM(Cl), commonly known as DMTMM, has found many applications as dehydro-condensation agent for the synthesis of amides and esters [36,40], collagen cross-linking [7,21,38], preparation of carboxymethylcellulose based films [39], amine grafting on hyaluronan [20,40,41], and peptide synthesis [42]. Additionally, the synthesis of a library of 2-(4,6-dimethoxy-1,3,5-triazinyl)trialkyl ammonium salts (DMT-Ams(X), X: Cl − or ClO 4 − ) and their activity as dehydro-condensation agents for the synthesis of amides, has been reported by Kunishima et al [43] (Figure 2).…”

Section: Introductionmentioning

confidence: 99%

Sustainable Triazine-Based Dehydro-Condensation Agents for Amide Synthesis

et al. 2021

Self Cite

Conventional methods employed today for the synthesis of amides often lack of economic and environmental sustainability. Triazine-derived quaternary ammonium salts, e.g., 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM(Cl)), emerged as promising dehydro-condensation agents for amide synthesis, although suffering of limited stability and high costs. In the present work, a simple protocol for the synthesis of amides mediated by 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and a tert-amine has been described and data are compared to DMTMM(Cl) and other CDMT-derived quaternary ammonium salts (DMT-Ams(X), X: Cl− or ClO4−). Different tert-amines (Ams) were tested for the synthesis of various DMT-Ams(Cl), but only DMTMM(Cl) could be isolated and employed for dehydro-condensation reactions, while all CDMT/tert-amine systems tested were efficient as dehydro-condensation agents. Interestingly, in best reaction conditions, CDMT and 1,4-dimethylpiperazine gave N-phenethyl benzamide in 93% yield in 15 min, with up to half the amount of tert-amine consumption. The efficiency of CDMT/tert-amine was further compared to more stable triazine quaternary ammonium salts having a perchlorate counter anion (DMT-Ams(ClO4)). Overall CDMT/tert-amine systems appear to be a viable and more economical alternative to most dehydro-condensation agents employed today.