scholarly journals Radical-induced cationic frontal polymerisation for prepreg technology

2021 ◽  
Vol 152 (1) ◽  
pp. 151-165
Author(s):  
Anh Dung Tran ◽  
Thomas Koch ◽  
Robert Liska ◽  
Patrick Knaack
Keyword(s):  
Mechanical Properties ◽  
Ring Opening ◽  
Storage Stability ◽  
Epoxy Group ◽  
Epoxide Resin ◽  
Ring Opening Reaction ◽  
Thermal Mechanical Properties ◽  
Radical Polymerisation ◽  
New Type ◽  
Dual Curing

AbstractIn this study, a new type of prepreg technology has been established using a dual curing system consisting of 1,6-hexanediol diacrylate (HDDA) and frontally polymerisable components based on the epoxide resin. The study of the polymerisation of HDDA revealed (tert-butylcyclohexyl)peroxydicarbonate (BCPC) as the most suitable radical thermal initiator. The presence of BCPC resulted in a fast radical polymerisation of HDDA and no cationic ring-opening reaction of the epoxy, which was observed by monitoring the double bond and epoxy group conversion in real time-NIR rheology measurement. The formed prepreg can subsequently be cured by radical-induced cationic frontal polymerisation of the epoxy resin. Effects of HDDA amount on the radical polymerisation, stiffness of the gel, frontal parameters and thermal mechanical properties of final polymers were investigated. With 10 wt% HDDA, the formed prepreg has very good storage stability, which was proved by monitoring the epoxy group conversion during 4 months of storage at 50 °C while still a stable front can be obtained. Furthermore, the RICFP-prepregs with different fibre contents were prepared and polymerised by RICFP. Then, a snowflake composite was successfully produced using RICFP-prepreg. Graphic abstract

Preparation and Properties of Waterborne Varnish for On-Demand Inkjet Printing

2021 ◽  
Author(s):  
Jilei Chao ◽  
Ruizhi Shi ◽  
Fuqiang Chu ◽  
Yanling Guo ◽  
Qian Deng
Keyword(s):  
Inkjet Printing ◽  
Ring Opening ◽  
Water Resistance ◽  
Epoxy Group ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Trimellitic Anhydride ◽  
Friction Resistance ◽  
Ring Opening Reaction ◽  
Film Forming

A kind of waterborne varnish for inkjet printing was synthesized, and properties of the waterborne varnish were characterized to make it suitable for the glazing requirements of inkjet printing and other printability requirements. The waterborne varnish was synthesized from epoxy resin (E-51), epoxy diluent (ED), acrylic acid, trimellitic anhydride, maleic anhydride and organic amine by three steps of ring opening reaction, esterification reaction, neutralization reaction. The viscosity, film-forming property, water absorption of waterborne varnish and the water resistance, lightness, wear resistance and bonding strength of coated paper were tested. The effects of the ratio of E-51 and ED in the polymerization system on the properties of waterborne varnish were studied. In the test of printability of self-made waterborne varnish, the absorption of digital inkjet paper to varnish and the influence of varnish on color reproduction of printed image were discussed and studied. The results show that when the molar ratio of epoxy group in E-51 and ED is about 1:1, the prepared varnish is suitable for inkjet printing, and its film-forming property, such as water resistance, adhesion and friction resistance are better. At the same time, its printability is also better.

Preparation, Characterization and Application of Siloxane Succinate Fatliquor

2011 ◽  
Vol 233-235 ◽  
pp. 292-297 ◽  
Author(s):  
Tao Tao Qiang ◽  
Xiang Luo ◽  
Long Fang Ren ◽  
Xue Chuan Wang ◽  
Bao Yuan He
Keyword(s):  
Molecular Structure ◽  
Mechanical Properties ◽  
Castor Oil ◽  
Ring Opening ◽  
Rapeseed Oil ◽  
Raw Materials ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
Dyeing Property ◽  
Ring Opening Reaction

The silicone succinate surfactant (PMPS) was synthesized by ring-opening reaction using polyether alcohol amine modified polysilosane (PAPS) with maleic anhydride (MA) as the raw materials, and p-toluenesulfonic acid (PTSA) was used as the catalyst. Sulfated castor oil and sulfated rapeseed oil were combinated with PMPS to prepare a new leather fatliqour (PMPSF) composed mainly of PMPS. The molecular structure of PMPS was characterized by FTIR spectra; the thermal properties of PMPS was characterized and analyzed by TGA. PMPSF was used in sheepskin wet blue leather and compared with oxidative sulfited vegetable oils (L-3) and RF-1 fatliquor; the waterproof and mechanical properties of the leather were measured. The results show that the thermal decomposition temperature of PMPS is 192.8°C. Fatliquor PMPSF provids a good level-dyeing property, the leather oiled by it has good flexibility and fullness, the waterproofness and mechanical properties of leather are also good. Moreover, compared with the leather fatliquored by L-3, the thickening rate of leather oiled by PMPSF reaches 13.7%.

scholarly journals Research Progress of Biodegradable Polyester Polyols Based on Ring-Opening Polymerization of Cyclohexene Carbonate

2020 ◽  
Vol 26 (3) ◽  
pp. 323-332
Author(s):  
Xuemei WANG ◽  
Xiang GUI ◽  
Yingping QI ◽  
Yongfeng SHEN ◽  
Hua LI
Keyword(s):  
Mechanical Properties ◽  
Ring Opening ◽  
Main Chain ◽  
Ring Opening Polymerization ◽  
Raw Material ◽  
Research Progress ◽  
Flexible Structure ◽  
Biological Stability ◽  
Thermal Mechanical Properties ◽  
Weather Resistance

The polycarbonate polyols(PCD) obtained by ring-opening polymerization of a general cyclic monomer is mostly a linear flexible structure, which is used as a raw material to synthesize polyurethanes, and it is difficult to simultaneously ensure good thermal-mechanical properties and weather resistance due to insufficient rigidity of the main chain. However, PCD based on ring-opening polymerization of cyclohexene carbonate (CHC), endowing with polyurethanes good mechanical properties, weather ability and biological stability because of the rigid structure of six-membered aliphatic rings in the main chain. Therefore, in this paper, the method and principle of preparing new polycarbonate polyols based on ring-opening polymerization of cyclohexene carbonate (CHC) are introduced. And the problems and countermeasures in its development and its application in polyurethane materials are discussed.

Preparation of Epoxy Modified Organosilicone High-Temperature Resistance Coatings

2008 ◽  
Vol 373-374 ◽  
pp. 434-437
Author(s):  
Hua Zhu ◽  
Zhi Lang Chen ◽  
Fang Nan ◽  
An Lin ◽  
Fu Xing Gan
Keyword(s):  
High Temperature ◽  
Epoxy Resin ◽  
Adhesion Strength ◽  
Ring Opening ◽  
Epoxy Group ◽  
Temperature Resistance ◽  
Ring Opening Reaction ◽  
High Temperature Resistance ◽  
Solidification Reaction ◽  
The Fourier Transform

An ambient-cured organosilicone resin modified with epoxy resin was synthesized with lab-synthesized polysiloxane resin and biphenix-A epoxy resin(E-20) by copolymerization at 180~190 °C for 2~3 hours. The effect of ratios between polysiloxane resin and E-20, reaction temperatures and reaction time on heat resistance and miscibility etc were discussed in detail. The experiment results showed that the epoxy modified organosilicone resin exhibited the best solubility performance and adhesion strength when the ratio of the polysiloxane resin to E-20 was 3:7. The Fourier transform infrared spectra (FTIR) revealed that hydroxy on epoxy resin had reacted with ethyoxyl on organic silicon molecular chain, but no ring-opening reaction happened on epoxy group of E-20. The excellent high-temperature resistance painting, based on these epoxy modified organosilicone resin was prepared with flake aluminum powder as temperature resistance filler, polyamide 650 as curer and WD-50 coupling agent as curing-promoter. It was shown that the temperature resistance was superior to 600°C and the adhesion strength of the coating was up to 1 grade. Scanning electron microscope(SEM) revealed the reaction happened on -Si-O-Si- and Al under high temperature improved the coatings to resist higher temperature. The mechanism of the high-temperature anticorrosion is attributed to “ring-opening reaction” and “cross-link solidification reaction”.

On the Conrotatory Ring Opening of 3-Carbomethoxycyclobutene Vis-À-Vis 3-Carbomethoxy-1,2-Benzocyclobutene and the Predominant Inward Opening of 3-Dimethylaminocarbonyl-1,2-Benzocyclobutene

2018 ◽  
Author(s):  
Veejendra Yadav ◽  
Dasari L V K Prasad ◽  
Arpita Yadav ◽  
Maddali L N Rao
Keyword(s):  
Transition State ◽  
Ring Opening ◽  
Electron Process ◽  
Ring Opening Reaction ◽  
Stable Species ◽  
Electron Event

<p>The torquoselectivity of conrotatory ring opening of 3-carbomethoxycyclobutene is controlled by p<sub>C1C2</sub>→s*<sub>C3C4</sub> and s<sub>C3C4</sub>→p*<sub>CO</sub> interactions in the transition state in a 4-electron process as opposed to only s<sub>C3C4</sub>→p*<sub>CO</sub> interaction in an apparently 8-electron event in 3-carbomethoxy-1,2-benzocyclobutene. The ring opening of 3-carbomethoxy-1,2-benzocyclobutene is sufficiently endothermic. We therefore argue that the reverse ring closing reaction is faster than the forward ring opening reaction and, thus, it establishes an equilibrium between the two and subsequently allows formation of the more stable species <i>via</i> outward ring opening reaction. Application of this argument to 3-dimethylaminocarbonyl-1,2-benzocyclobutene explains the predominantly observed inward opening.</p>

scholarly journals Expanding Monomers as Anti-Shrinkage Additives

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 806
Author(s):  
Philipp Marx ◽  
Frank Wiesbrock
Keyword(s):  
Ring Opening ◽  
Covalent Bond ◽  
Volumetric Shrinkage ◽  
Structure Property ◽  
Atomic Packing ◽  
Materials Properties ◽  
Volumetric Expansion ◽  
Structure Property Relationships ◽  
Ring Opening Reaction ◽  
Measuring Techniques

Commonly, volumetric shrinkage occurs during polymerizations due to the shortening of the equilibrium Van der Waals distance of two molecules to the length of a (significantly shorter) covalent bond. This volumetric shrinkage can have severe influence on the materials’ properties. One strategy to overcome this volumetric shrinkage is the use of expanding monomers that show volumetric expansion during polymerization reactions. Such monomers exhibit cyclic or even oligocyclic structural motifs with a correspondingly dense atomic packing. During the ring-opening reaction of such monomers, linear structures with atomic packing of lower density are formed, which results in volumetric expansion or at least reduced volumetric shrinkage. This review provides a concise overview of expanding monomers with a focus on the elucidation of structure-property relationships. Preceded by a brief introduction of measuring techniques for the quantification of volumetric changes, the most prominent classes of expanding monomers will be presented and discussed, namely cycloalkanes and cycloalkenes, oxacycles, benzoxazines, as well as thiocyclic compounds. Spiroorthoesters, spiroorthocarbonates, cyclic carbonates, and benzoxazines are particularly highlighted.

Design and synthesis of 1,8-Naphthalimide Functionalized Benzothiadiazoles

2021 ◽  
Author(s):  
Rajneesh Misra ◽  
Yogjivan Rout
Keyword(s):  
Ring Opening ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Design And Synthesis ◽  
Cross Coupling Reaction ◽  
Ring Opening Reaction

A series of multi acceptor based push-pull derivatives BTD2–BTD5 were designed and synthesized via Pd-catalyzed Sonogashira cross-coupling reaction followed by [2+2] cycloaddition–electrocyclic ring-opening reaction in which benzothiadiazole (BTD, A1), naphthalimide...

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