scholarly journals Study on the synthesis and thermal stability of silicone resins reinforced by Si–O–Ph cross-linking

RSC Advances ◽  
2021 ◽  
Vol 11 (49) ◽  
pp. 30971-30979
Author(s):  
Huadong Zhang ◽  
Zhongyi Yan ◽  
Zhizhou Yang ◽  
Jinshui Yao ◽  
Qiuhong Mu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Catalytic Hydrogenation ◽  
Phenolic Hydroxyl ◽  
Cross Linking ◽  
Silicone Resin ◽  
Oh Groups ◽  
Thermal Stability Of

A novel silicone resin (SR-OH) containing phenolic hydroxyl (Ph–OH) groups was designed and synthesized via co-hydrolysis/condensation and catalytic hydrogenation.

Cross-linking of atoms and thermal stability of new MDF compositions

1996 ◽  
Vol 46 (2) ◽  
pp. 479-487 ◽  
Author(s):  
M. Drábik ◽  
Lubica Gáliková ◽  
Zuzana Sadleková ◽  
Mária Kubranová
Keyword(s):  
Thermal Stability ◽  
Cross Linking ◽  
Thermal Stability Of

scholarly journals Effect of Nanodiamond Particles on Properties of Epoxy Composites

2008 ◽  
Vol 17 (1) ◽  
pp. 096369350801700 ◽  
Author(s):  
Zdeno Špitalský ◽  
Alexander Kromka ◽  
Libor Matějka ◽  
Peter Černoch ◽  
Jana Kovářová ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Epoxy Composites ◽  
Neat Epoxy ◽  
Light Transmittance ◽  
Cross Linking ◽  
Amino Groups ◽  
Multiwalled Carbon ◽  
Epoxy Network ◽  
Epoxy Nanocomposite ◽  
Thermal Stability Of

The epoxy nanocomposites filled with 0.1, 0.5, and 1 wt% nanodiamonds (nanoD) were prepared and their properties were compared with neat epoxy network or epoxy nanocomposite filled with 1 wt% multiwalled carbon nanotubes (MWCNTs). The obtained nanoD-epoxy composites increased significantly thermal stability of prepared nanocomposites in comparison with neat epoxy matrix. The exponential decay of light transmittance with increasing concentration of nanoD in sample was observed. The values of storage modulus G` and glass transition temperature Tg significantly decreased by addition of nanoD to epoxy network. This is caused by inhibition of cross-linking reaction of epoxy- and amino- groups by nanoD.

Influence of the Precursor Cross-Linking Route on the Thermal Stability of Si−B−C−O Ceramics

2008 ◽  
Vol 20 (22) ◽  
pp. 7148-7156 ◽  
Author(s):  
Vladislav Ischenko ◽  
Eckhard Pippel ◽  
Jörg Woltersdorf ◽  
B. Rodrigue Ngoumeni Yappi ◽  
Ralf Hauser ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Cross Linking ◽  
Thermal Stability Of

scholarly journals Thermal stability of polyurethane coating prepared by using diphenylolpropane

2020 ◽  
Vol 62 (4) ◽  
pp. 81-87
Author(s):  
Indira N. Bakirova ◽  
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Weight Loss ◽  
Elevated Temperatures ◽  
Onset Temperature ◽  
Phenolic Hydroxyl ◽  
Hydroxyl Groups ◽  
Polyurethane Coating ◽  
Urethane Group ◽  
Thermal Stability Of

Thermal stability of polyurethane varnish coating prepared by using diphenylolpropane, polyetherpolyol and polyisocyanate with an equimolar ratio of isocyanate and hydroxyl groups was assessed in the air. The polyurethane weight loss thermogram shows three temperature regions: I – (217-275)°С, II – (275-380)°С, and III – above 380°С. For interpreting thermogram of the polyurethane under study the model substances simulating the urethane groups of a polymer were synthesized. The substance containing the urethane group formed by phenolic hydroxyl of diphenylolpropane was shown to demonstrate relatively low thermal stability and gets broken down into isocyanate and bisphenol. Decomposition of the substance containing the urethane group formed by alcoholic hydroxyl occurs at the higher temperature. The data obtained allow interpreting the occurrence of thermal decomposition step I in TGA curve by structural changes in the blocks formed by diphenylolpropane and polyisocyanate being the least stable when exposed to elevated temperatures. The next step can be attributed to decomposition of more thermostable urethane groups formed by functional groups of oligooxypropylenetriol and polyisocyanate. Transition to the step III accompanied by severe sample weight loss due to decomposition of urethane groups is explained by thermal oxidation of oligoether units of polymer. Based on the data obtained the conclusion was made that the presence of urethane groups formed by phenolic hydroxyl of diphenylolpropane in polymer structure results in the decreased thermooxidative decomposition onset temperature of polymer. At the same time, a deceleration of thermooxidative processes due to the stabilizing effect of diphenylolpropane released at the beginning of thermal decomposition of polyurethane is observed in a high-temperature region. The proposed polyurethane coating is inferior to commercial counterparts in thermal decomposition onset temperature but superior to them in the temperature corresponding to a 50% polymer weight loss.

scholarly journals Thermal stability of segmented polyurethane elastomers reinforced by clay particles

2009 ◽  
Vol 63 (6) ◽  
pp. 621-628 ◽  
Author(s):  
Jelena Pavlicevic ◽  
Jaroslava Budinski-Simendic ◽  
Mészáros Szécsényi ◽  
Nada Lazic ◽  
Milena Spirkova ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Chain Extender ◽  
Hexamethylene Diisocyanate ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Polyurethane Elastomers ◽  
Oh Groups ◽  
Clay Nanoparticles ◽  
Thermal Stability Of

The aim of this work was to determine the influence of clay nanoparticles on thermal properties of segmented polyurethanes based on hexamethylene- diisocyanate, aliphatic polycarbonate diol and 1,4-butanediol as chain extender. The organically modified particles of montmorillonite and bentonite were used as reinforcing fillers. The structure of elastomeric materials was varied either by diol type or chain extender content. The ratio of OH groups from diol and chain extender (R) was either 1 or 10. Thermal properties of prepared materials were determined using modulated differential scanning calorimetry (MDSC). Thermal stability of obtained elastomers has been studied by simultaneously thermogravimetry coupled with DSC. The glass transition temperature, Tg, of soft segments for all investigated samples was about -33?C. On the basis of DTG results, it was concluded that obtained materials were very stable up to 300?C.

Thermal stability of lignin in ground pulp (GP) and the effect of lignin modification on GP’s thermal stability: TGA experiments with dimeric lignin model compounds and milled wood lignins

Holzforschung ◽  
2019 ◽  
Vol 73 (5) ◽  
pp. 493-499 ◽  
Author(s):  
Daisuke Ando ◽  
Fumiaki Nakatsubo ◽  
Hiroyuki Yano
Keyword(s):  
Thermal Stability ◽  
Model Compound ◽  
Pinus Densiflora ◽  
Wood Fiber ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Oh Groups ◽  
Lignin Model Compound ◽  
Lignin Model ◽  
Thermal Stability Of

Abstract For ground pulp (GP) utilization in wood fiber composites as reinforced material, its thermal behavior is relevant. The contribution of lignin to thermal performance of GP from Pinus densiflora was the focus of the present study. Dimeric lignin model compounds and isolated milled wood lignins (MWLs) from three sources were submitted for thermogravimetric analysis (TGA). The temperatures leading to 1% weight loss (T per 1% WL) for the material were determined. The thermal stability of β-O-4 models was the lowest. Among the MWLs, the abaca MWL with its high β-O-4 content was the least thermostable. An acetylated nonphenolic β-O-4 lignin model compound showed that acetylation improves the thermal stability of this type of dimeric models. The acetylation of benzylic OH groups in β-O-4 linkages is especially relevant for the thermal resistance, which was also shown based on pre-acetylated benzylic OH groups in the GP before the total acetylation.

Photo-Cross-Linking-Assisted Thermal Stability of DNA Origami Structures and Its Application for Higher-Temperature Self-Assembly

2011 ◽  
Vol 133 (37) ◽  
pp. 14488-14491 ◽  
Author(s):  
Arivazhagan Rajendran ◽  
Masayuki Endo ◽  
Yousuke Katsuda ◽  
Kumi Hidaka ◽  
Hiroshi Sugiyama
Keyword(s):  
Thermal Stability ◽  
Self Assembly ◽  
Dna Origami ◽  
Cross Linking ◽  
Higher Temperature ◽  
Thermal Stability Of

Characterization of Thermal Reversible Cross-Linking Agents for Flexible Poly(vinyl chloride)

2014 ◽  
Vol 900 ◽  
pp. 3-6 ◽  
Author(s):  
Jing Wang ◽  
Wei Fang ◽  
Yuan Yuan ◽  
Xiao Ming Liu
Keyword(s):  
Thermal Stability ◽  
Vinyl Chloride ◽  
Congo Red ◽  
Cross Linking ◽  
Gel Content ◽  
Ethyl Mercaptan ◽  
Poly Vinyl Chloride ◽  
The Cross ◽  
Thermal Stability Of

In order to improve thermal stability of Poly (Vinyl Chloride), a kind of thermal reversible cross-linking agents, the end cyclopentadienyl ethanethiol salts, sodium cyclopentadienyl ethyl mercaptan (CPD-C2H4SNa) was synthesized in this paper. The DSC results proved that the prepared CPD-C2H4SNa has obvious thermal reversible characteristics and the thermal reversible temperature was at 177 °C. The effects of cross-linking agent amount, cross-linking reactive time and temperature on flexible PVC compounds were evaluated through gel content testing. It was showed that the cross-linking agent with 3 Phr is optimum for PVC compounds. Moreover, both the cross-linking reactive time and temperature has effects on gel content of PVC compounds. The gel content of CPD-C2H4SNa cross-linked PVC compounds reaches maximum at 76% for 20 min at 160 °C.The static thermal stability of flexible PVC was measured according to congo red method. The results showed that the thermal stability of PVC compounds was enhanced with increasing cross-linking agent amount.

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