Preparation and Properties of Thiol-Ene UV-Curable Fluorinated Emulsion

2014 ◽  
Vol 960-961 ◽  
pp. 138-142 ◽  
Author(s):  
Xiu Zhen Hu ◽  
Hua Yun Cheng ◽  
Wen Hua Deng ◽  
Chang Qing Fu

Single electron transfer living radical emulsion polymerization (SET-LRP) of allyl methacrylate (AMA) coupled with 2,2,3,4,4,4-hexafluorobutyl methacrylate (HFBA) was investigated in the presence of Cu(0)/N,N,N’,N’’,N’’-pentamethyldiethylenetriamine (PMDETA) as catalyst and ethyl 2-bromoisobutyrate (EBiB) as initiator. Solid content of the emulsion and the amount of the catalyst, initiator and emulsifier were discussed for the optimal reaction conditions. Then, the emulsion was combined with thiol capped polyurethane (SHPU) under UV to form the UV curable fluorinated films. Mechanical properties and contact angle of the UV cured films were studied.

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1424
Author(s):  
Mariola Robakowska ◽  
Łukasz Gierz ◽  
Hubert Gojzewski

This article describes the modification of UV-curable coatings with silicon aluminum oxynitride (Sialon) and aluminum oxide (Alu C), which improve the hydrophobicity of the coating surface and the scratch hardness. The contact angle is greater due to surface roughness being enhanced with inorganic fillers. Improved scratch resistance results from the formation of a sliding layer triggered by the diffusion of Sialon or alumina on the coating surface. One can observed an increase in the surface hydrophobicity as well as in the scratch hardness (up to 100%) when small amounts (5 wt.%) of the inorganic compounds are added. Imaging microscopies, i.e., SEM, OM, and AFM (with nanoscopic Young’s modulus determination), revealed the good distribution of both types of fillers in the studied matrix.


2020 ◽  
Author(s):  
Lei Chen ◽  
Shiyi Jin ◽  
Jian Gao ◽  
Tongtong Liu ◽  
Yuebo Shao ◽  
...  

An N-heterocyclic carbene and magnesium co-catalyzed three-component alkylacylation of alkenes with cycloketone oxime esters and aldehydes was presented. This method displayed good scope generality, providing a transition metal and photo-redox free pathway to access various multi-functionalized aliphatic keto-nitrile structures under mild reaction conditions. Moreover, this strategy is supposed to follow a radical relay mechanism via a single electron transfer (SET) event of Mg/oxime ester/Breslow intermediate ternary electron donating acceptor (EDA) complex.


Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 459 ◽  
Author(s):  
Hengzhao Li ◽  
Zemin Lai ◽  
Adila Adijiang ◽  
Hongye Zhao ◽  
Jie An

Functionalization of amide bond via the cleavage of a non-carbonyl, C-N σ bond remains under-investigated. In this work, a transition-metal-free single-electron transfer reaction has been developed for the C-N σ bond cleavage of N-acylazetidines using the electride derived from sodium dispersions and 15-crown-5. Of note, less strained cyclic amides and acyclic amides are stable under the reaction conditions, which features the excellent chemoselectivity of the reaction. This method is amenable to a range of unhindered and sterically encumbered azetidinyl amides.


2020 ◽  
Vol 7 (16) ◽  
pp. 2269-2277
Author(s):  
Zunyun Fu ◽  
Xutong Li ◽  
Zhaohui Wang ◽  
Zhaojun Li ◽  
Xiaohong Liu ◽  
...  

Deep learning was used to optimize chemical reactions with the quantum mechanical properties of chemical contexts and reaction conditions as inputs. The trained deep learning model determines optimal reaction conditions by in silico exploration of accessible reaction space.


2020 ◽  
Vol 16 ◽  
pp. 1335-1342
Author(s):  
Shrikant D Tambe ◽  
Kwan Hong Min ◽  
Naeem Iqbal ◽  
Eun Jin Cho

A simple photocatalytic method was developed for the synthesis of unsymmetrical 1,2-diamines by the unprecedented reductive coupling of N-benzylidene-[1,1'-biphenyl]-2-amines with an aliphatic amine. The presence of a phenyl substituent in the aniline moiety of the substrate was critical for the reactivity. The reaction proceeded via radical–radical cross-coupling of α-amino radicals generated by proton-coupled single-electron transfer in the presence of an Ir photocatalyst. On the other hand, symmetrical 1,2-diamines were selectively produced from the same starting materials by the judicious choice of the reaction conditions, showcasing the distinct reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines. The developed method can be employed for the synthesis of various bulky vicinal diamines, which are potential ligands in stereoselective synthesis.


2020 ◽  
Author(s):  
Lei Chen ◽  
Shiyi Jin ◽  
Jian Gao ◽  
Tongtong Liu ◽  
Yuebo Shao ◽  
...  

An N-heterocyclic carbene and magnesium co-catalyzed three-component alkylacylation of alkenes with cycloketone oxime esters and aldehydes was presented. This method displayed good scope generality, providing a transition metal and photo-redox free pathway to access various multi-functionalized aliphatic keto-nitrile structures under mild reaction conditions. Moreover, this strategy is supposed to follow a radical relay mechanism via a single electron transfer (SET) event of Mg/oxime ester/Breslow intermediate ternary electron donating acceptor (EDA) complex.


2021 ◽  
Author(s):  
Xinyi Cheng ◽  
Xingchen Liu ◽  
Shengchun Wang ◽  
Ying Hu ◽  
Bingjing Hu ◽  
...  

Abstract A set of cobalt-catalyzed regioselective difluoroalkylarylation of both activated and unactivated alkenes with bench-stable solid arylzinc pivalates and difluoroalkyl bromides through a cascade Csp3‒Csp3/Csp3‒Csp2 bond formation has been developed under mild reaction conditions. Indeed, a wide range of functional groups on difluoroalkyl bromides, olefins, 1,3-dienes as well as (hetero)arylzinc pivalates are well tolerated by the cobalt-catalyst, thus furnishing three-component coupling products in good yields and with high regio- and diastereoselectivity. Kinetic experiments comparing arylzinc pivalates and conventional arylzinc halides highlight the unique reactivity of these new organozinc pivalates. Detailed mechanistic studies strongly support that the reaction involves direct halogen atom abstraction via single electron transfer to difluoroalkyl bromides from the in situ formed cobalt(I) species, thus realizing a Co(I)/Co(II)/Co(III) catalytic cycle.


MRS Advances ◽  
2018 ◽  
Vol 3 (61) ◽  
pp. 3601-3610 ◽  
Author(s):  
María E. Castelló ◽  
Pablo S. Anbinder ◽  
Javier I. Amalvy ◽  
Pablo J. Peruzzo

This work presents the study of the isolation of chitin from residues of the Patagonian shrimp (Pleoticus muelleri), and its subsequent conversion to chitosan under different reaction conditions. The obtained products were characterized by evaluating their molecular weight (Mw) and degree of deacetylation (DD). In addition, chitosan- glycerol films were prepared (5, 10 and 20% w/w of plasticizer content), using a neutralization process during the unmolding step. The films were characterized by infrared (FTIR) and UV-Visible spectroscopy and scanning electron microscopy (SEM). In addition, its behavior against water (contact angle and water sorption) and mechanical properties were also studied. It was observed that 72 hours of reaction time at 120 °C were necessary to obtain a chitosan sample with the desirable solubility properties from the chitin extracted from Pleoticus muelleri shells. The chitosan-glycerol films turned out to be systems of high transparency and their properties depended on the plasticizer content, obtaining homogeneous systems for concentrations up to 10% w/w. In addition, the films were found to be more hydrophilic than the reference material, with smaller contact angle and greater water absorption values, obtaining more flexible films in view of their mechanical properties.


2011 ◽  
Vol 306-307 ◽  
pp. 1663-1666
Author(s):  
Rui Fang Guan ◽  
Yu Rong Dong

Polysiloxanes with cyanoethyl groups (PDMS-CN) is a useful functional polysiloxanes. In this paper, the polysiloxane with various number average molecular weight (Mn) and cyanoethyl groups were prepared. Mns of PDMS-CN were determined by GPC. The contents of cyanoethyl groups were determined by 1H NMR. The dynamic mechanical properties and thermal stability of PDMS-CN were investigated by DSC and TGA respectively. The hydrolysis of PDMS-CNs give the polysiloxanes with carboxyl groups. The factors influencing the hydrolysis of cyanoethyl groups were discussed by orthogonal array and the optimal reaction conditions were confirmed. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text


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