Recyclable and Reprocessable Thermosetting Polyurea with High Performance Based on Diels-Alder Dynamic Covalent Crosslinking

2021 ◽  
Vol 29 (8) ◽  
pp. 562-568
Author(s):  
Zhengkai Wei ◽  
Yi Wang ◽  
Xiaowei Fu ◽  
Liang Jiang ◽  
Yuechuan Wang ◽  
...  
Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 347
Author(s):  
Jana Machotová ◽  
Andréa Kalendová ◽  
Denisa Steinerová ◽  
Petra Mácová ◽  
Stanislav Šlang ◽  
...  

This paper deals with the development of acrylic latexes providing high-performance water-resistant coatings. For this purpose, mutual effects of anionic surfactant type (ordinary and polymerizable), covalent intra- and/or interparticle crosslinking (introduced by allyl methacrylate copolymerization and keto-hydrazide reaction, respectively) and ionic crosslinking (provided by nanostructured ZnO additive) were investigated. The latexes were prepared by the standard emulsion polymerization of methyl methacrylate, butyl acrylate and methacrylic acid as the main monomers. The addition of surface-untreated powdered nanostructured ZnO was performed during latex synthesis, resulting in stable latexes comprising dispersed nanosized additive in the content of ca 0.9-1.0 wt.% (based on solids). The coating performance with emphasis on water resistance was evaluated. It was determined that the application of the polymerizable surfactant improved coating adhesion and water-resistance, but it wasn′t able to ensure high water-resistance of coatings. Highly water-resistant coatings were obtained provided that covalent intra- and interparticle crosslinking together with ionic crosslinking were employed in the coating composition, forming densely crosslinked latex films. Moreover, coatings comprising nanostructured ZnO additive displayed a significant antibacterial activity and improved solvent resistance.


2020 ◽  
Vol 139 ◽  
pp. 105473 ◽  
Author(s):  
Jinfeng Chi ◽  
Guoliang Zhang ◽  
Qingyi Xie ◽  
Chunfeng Ma ◽  
Guangzhao Zhang

Polymer ◽  
2018 ◽  
Vol 142 ◽  
pp. 33-42 ◽  
Author(s):  
Kaiju Luo ◽  
Jing Li ◽  
Guangyu Duan ◽  
Yan Wang ◽  
Junrong Yu ◽  
...  

RSC Advances ◽  
2017 ◽  
Vol 7 (73) ◽  
pp. 46336-46343 ◽  
Author(s):  
Chenting Cai ◽  
Yue Zhang ◽  
Xueting Zou ◽  
Rongchun Zhang ◽  
Xiaoliang Wang ◽  
...  

A rapid self-healing and recyclable high-performance crosslinked epoxy resin (ER)/graphene nanocomposite is reported by simultaneously incorporating thermally reversible Diels–Alder (DA) covalent bonds and multiple-responsive graphene into the ER matrix.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sivalingam Ramesh ◽  
Jaehwan Kim ◽  
Joo-Hyung Kim

Recently, cellulose has much attention as an emerging renewable nanomaterial which holds promising properties having unique piezoelectricity, insulating, and biodegradable nature for various applications. Also, the modified properties of cellulose by appropriate chemical modifications in various functional groups with outstanding properties or significantly improved physical, chemical, biological, and electronic properties will widen the way for it to be utilized in different usages. Therefore, in this paper, cellulose-functionalized polyhedral oligomeric silsesquioxanes (POSS) based materials were considered an important class of high-performance hybrid nanocomposite materials. To functionalize the regenerated cellulose, amino functionalized POSS material was synthesized via sol-gel covalent crosslinking process in presence of amino coupling agent. In this reaction, tetraethoxsilane (TEOS) andγ-aminopropyltriethoxy silane (γ-APTES) as coupling agent for metal precursors were selected. The chemical structure of cellulose-amine functionalized bonding and covalent crosslinking hybrids was confirmed by FTIR and1H NMR spectral analysis. From the TEM results, well-dispersed hybrid cellulose-functionalized POSS-silica composites are observed. The resulting cellulose-POSS-silica hybrid nanocomposites materials provided significantly improved the optical transparency, and thermal and morphological properties to compare the cellulose-silica hybrid materials. Further, antimicrobial test against pathogenic bacteria was carried out.


2013 ◽  
Vol 634-638 ◽  
pp. 642-646 ◽  
Author(s):  
Sung Ho Park ◽  
Jun Seong Park ◽  
Tae Won Ko ◽  
Yong Sung Park ◽  
Je Wan Woo

Norbornene dicarboxylate was synthesized through esterification under titanium catalyst. The alcohols are 2-ethyl-1-hexanol, n-octanol, 3,5,5-trimethyl-1-hexanol, and n-decanol. The Structures of compounds were identified by 1H-NMR, and then components were identified by high performance liquid chromatography (HPLC). The yield and purity was over 90 % and 95 %, and color of compounds was colorless or light yellow. The maleate as a by-product was occured by the retro Diels-Alder reaction.


Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1288 ◽  
Author(s):  
Chengguo Liu ◽  
Cuina Wang ◽  
Jijun Tang ◽  
Jing Zhang ◽  
Qianqian Shang ◽  
...  

Graphene-reinforced tung oil (TO)-based unsaturated polyester nanocomposites were prepared via in situ melt polycondensation intergrated with Diels–Alder addition. Functionalized graphene sheets derived from graphene oxide (GO) were then extracted from the obtained nanocomposites and carefully characterized. Furthermore, dispersion state of the graphene nanosheets in the cured polymer composites and ultimate properties of the resultant biobased nanocomposites were investigated. Mechanical and thermal properties of the TO-based unsaturated polyester resin (UPR) were greatly improved by the incorporation of GO. For example, at the optimal GO content (only 0.10 wt %), the obtained biobased nanocomposite showed tensile strength and modulus of 43.2 MPa and 2.62 GPa, and Tg of 105.2 °C, which were 159%, 191%, and 49.4% higher than those of the unreinforced UPR/TO resin, respectively. Compared to neat UPR, the biobased UPR nanocomposite with 0.1 wt % of GO even demonstrated superior comprehensive properties (comparable stiffness and Tg, while better toughness and thermal stability). Therefore, the developed biobased UPR nanocomposites are very promising to be applied in structural plastics.


2021 ◽  
Author(s):  
Jiale Ye ◽  
Songqi Ma ◽  
Binbo Wang ◽  
Qingming Chen ◽  
Kaifeng Huang ◽  
...  

Ferulic acid-derived diepoxy was facilely synthesized and co-cross-linked with furfuryl alcohol monoepoxy accompanying the Diels–Alder reaction to achieve high-performance thermosets.


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