scholarly journals Anionic Copolymerization of Styrene Sulfide with Elemental Sulfur (S8)

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2597
Author(s):  
Jakub Wręczycki ◽  
Dariusz M. Bieliński ◽  
Marcin Kozanecki ◽  
Paulina Maczugowska ◽  
Grzegorz Mlostoń
Keyword(s):  
Thermal Stability ◽  
Raman Spectroscopy ◽  
Ring Opening ◽  
Chemical Structure ◽  
Elemental Sulfur ◽  
Ring Opening Polymerization ◽  
Spectroscopic Methods ◽  
Initial Ratio ◽  
Anionic Copolymerization ◽  
Thermal Stability Of

The superior ability of thiiranes (episulfides) to undergo ring-opening polymerization (ROP) in the presence of anionic initiators allows the preparation of chemically stable polysulfide homopolymers. Incorporation of elemental sulfur (S8) by copolymerization below the floor temperature of S8 permits the placement of a large quantity of sulfur atoms in the polysulfide mainchain. The utility of styrene sulfide (2-phenylthiirane; StS) for copolymerization with elemental sulfur is reported here. A few polysulfides differing depending on the initial ratio of S8 to StS and copolymerization time were synthesized. Various spectroscopic methods (1H NMR, 13C NMR, Raman spectroscopy and FTIR spectroscopy) were applied to characterize the chemical structure of the copolymers. Additionally, the phase structure and thermal stability of the synthesized polysulfides were investigated using DSC and TGA, respectively. The successful anionic copolymerization of styrene sulfide and elemental sulfur has been demonstrated.

Biodegradable Poly(lactic Acid)/TDI-Montmorillonite Nanocomposites: Preparation and Characterization

2011 ◽  
Vol 221 ◽  
pp. 211-215 ◽  
Author(s):  
Na Li Chen ◽  
Hui Xia Feng ◽  
Jing Wei Guo ◽  
He Ming Luo ◽  
Jian Hui Qiu
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Decomposition Temperature ◽  
Toluene Diisocyanate ◽  
Poly Lactic Acid ◽  
Infrared Spectrometry ◽  
Ft Ir ◽  
Thermal Stability Of

Activated montmorillonite(MMT) was modified by toluene diisocyanate(TDI) and TDI-montmorillonite(TDI-MMT) was prepared. The characterization of TDI-MMT was carried out by X-ray diffraction(XRD) and fourier transform infrared spectrometry (FT-IR). The results showed that TDI had been inserted to the interlayer of MMT and the interlayer spacing of MMT increased by 0.26nm. With stannous chloride as catalyst, the biodegradable polylactide acid/TDI-montmorillonite(PLA/TDI-MMT) nanocomposites were synthesized through ring-opening polymerization of lactide in the layer of TDI-MMT by in-situ polymerization. The structure and thermal stability of nanocomposites were investigated by XRD, FT-IR and thermogravimetry (TG). Exfoliated nanocomposites were obtained as shown by XRD results. FT-IR spectra confirmed that TDI-MMT participated in the ring-opening polymerization of lactide. TG analysis indicated the decomposition temperature of nanocomposites rose and the thermal stability was improved contrast to the neat PLA. The effect of the content of TDI-MMT on the molecular weight and thermal stability of nanocomposites was studied. With the increase of the proportion of TDI-MMT, the molecular weight of resultant nanocomposites decreased and the decomposition temperature rose at the range of experiment research.

Preparation and Properties of Polybenzoxazine/Lignin Alloy

2012 ◽  
Vol 217-219 ◽  
pp. 571-577 ◽  
Author(s):  
H.M. Emranul Haque ◽  
Zahidul Islam ◽  
Takehiro Kawauchi ◽  
Tsutomu Takeichi
Keyword(s):  
Thermal Stability ◽  
Ring Opening ◽  
Lignin Content ◽  
Weight Ratio ◽  
Alloy Film ◽  
Ring Opening Polymerization ◽  
Scanning Calorimetry ◽  
Alloy Films ◽  
Degradation Temperature ◽  
Thermal Stability Of

Polymer alloys of polybenzoxazine and lignin were prepared by mixing benzoxazine and lignin, followed by curing. The ring-opening polymerization of benzoxazine in the presence of lignin was investigated by differential scanning calorimetry. It was found that lignin accelerates the ring-opening polymerization of benzoxazine. Polybenzoxazine/lignin alloy films were prepared by varying the weight ratio of benzoxazine and lignin. Transparent alloy film was obtained up to 2 wt. % content of lignin, but phase separation was observed at higher content of lignin. Thermal stability of the alloy films was examined by thermogravimetric analysis from 40 °C to 850 °C. The alloy film with 10 wt. % lignin showed highest onset of degradation temperature. Moreover, char yield of alloy films was increased with increasing the lignin content, suggesting higher flame retardancy of the alloy films than the pristine polybenzoxazine.

Synthesis of biomass based plasticizer from linoleic acid and cardanol for preparing durable PVC material

2021 ◽  
Author(s):  
Hongying Chu ◽  
Huabei Li ◽  
Xiaoyan Sun ◽  
Yaowang Zhang
Keyword(s):  
Thermal Stability ◽  
Linoleic Acid ◽  
Chemical Structure ◽  
Dioctyl Phthalate ◽  
H Nmr ◽  
Plasticized Pvc ◽  
Migration Resistance ◽  
Ft Ir ◽  
And Migration ◽  
Thermal Stability Of

Abstract In this paper, we synthesized a kind of bio-based plasticizer epoxidized linoleic acid cardanol ester(ELCE) from cardanol and linoleic acid. Its chemical structure was characterized with FT-IR and 1H NMR. Polyvinyl chloride(PVC) blends plasticized with ELCE were prepared via thermoplastic blending with torque rheometer. The performance including torque, mechanical property, thermal stability, plasticizing property and migration resistance of plasticized PVC blends were investigated and compared with plasticized PVC blends with commercial plasticizer dioctyl phthalate(DOP). The results showed that ELCE improved thermal stability of PVC blends. ELCE played more excellent plasticizing effect on PVC blends than DOP. The better solvent extraction resistance and volatile resistance of ELCE make it impossible to completely replace DOP in PVC products.

Systematic Characterization of Different Quaternary Ammonium Salts to be Used in Organoclays

2012 ◽  
Vol 727-728 ◽  
pp. 1552-1556
Author(s):  
Renata Barbosa ◽  
Dayanne Diniz Souza ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Thermal Stability ◽  
Quaternary Ammonium ◽  
Chemical Structure ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Degradation Mechanisms ◽  
Scanning Calorimetry ◽  
Higher Temperature ◽  
Thermal Stability Of

Studies of degradation have verified that the decomposition of some quaternary ammonium salts can begin to be significant at the temperature of about 180 ° C and like most thermoplastics are processed at least around this temperature, the thermal stability of the salt in clay should always be considered. Some salts are more stable than others, being necessary to study the degradation mechanisms of each case. In this work, four quaternary ammonium salts were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results of DSC and TG showed that the salts based chloride (Cl-) anion begin to degrade at similar temperatures, while the salt based bromide (Br-) anion degrades at higher temperature. Subsequently, a quaternary ammonium salt was chosen to be used in organoclays, depending on its chemical structure and its thermal behavior.

Novel Thermally Stable Epoxy-polyurethane Composites: Preparation, Characterization

2011 ◽  
Vol 239-242 ◽  
pp. 2742-2747
Author(s):  
Jing Lin ◽  
Qiu Zhuan Yang ◽  
Xiu Fang Wen ◽  
Zhi Qi Cai ◽  
Pi Hui Pi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ring Opening ◽  
Thermal Characteristics ◽  
Ring Opening Reaction ◽  
Tetramethylammonium Bromide ◽  
One Step ◽  
Novolac Epoxy ◽  
Polyurethane Composites ◽  
Novolac Epoxy Resins ◽  
Thermal Stability Of

A novel series of hydroxyl terminated bisphenol-A type novolac epoxy resins modified with propionic acid (MEP) were prepared by one-step ring-opening reaction process in the presence of tetramethylammonium bromide catalyst. The obtained MEP was characterized using FTIR,1HNMR analyses. In addition, Intercross-linked epoxy-polyurethane composites networks were also obtained by curing reaction among MEP, cross linker polyisocyanate IL1351 and phthalic anhydride. The thermal characteristics of the epoxy-polyurethane composites were determined by thermogravimetric analysis (TGA). The thermal stability of the cured MEP with different ring-opening rate and cured alkyd polyol A450 were compared. The results showed that the obtained epoxy-polyurethane composites had much better thermal stability than the conventional polyurethane system A450/IL1351, and the thermal stability of them was correlated to the content of MEP.

Study on the Thermal Stability of Selected Ionic Liquids

2015 ◽  
Vol 220-221 ◽  
pp. 218-223
Author(s):  
Tomasz Jan Kaldonski ◽  
Stanislaw Cudzilo
Keyword(s):  
Higher Education ◽  
Thermal Stability ◽  
Ionic Liquids ◽  
High Temperature ◽  
Thermal Resistance ◽  
Chemical Structure ◽  
Research Project ◽  
High Thermal Resistance ◽  
Thermal Stability Of

Some results of tests of the thermal stability (and volatility) of selected ionic liquids pondered as lubricating substances in comparison with typical lubricating, mineral and synthetic oils, are presented in the article. The research was carried out within the framework of PBR/15–249/2007/WAT–OR00002904 Research Project Financed by the Ministry of Science and Higher Education, during 2007–2011 [1]. The obtained results confirmed high thermal resistance of ionic liquids. It makes it possible to use the liquids as high temperature lubricating substances. At the same time, it has been stated that the thermal resistance of ionic liquids depends on the composition and chemical structure of anion and cation.

Relationship between the chemical structure and thermal stability of emulsion PVC

1981 ◽  
Vol 23 (5) ◽  
pp. 1204-1209 ◽  
Author(s):  
V.V Lisitskii ◽  
V.G Kalashnikov ◽  
V.P Biryukov ◽  
V.A Musikhin ◽  
K.S Minsker
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Thermal Stability Of ◽  
Stability Of Emulsion

Characterization of Ni- and Ni(Pt)-Silicide Formation on Narrow Polycrystalline Si Lines by Raman Spectroscopy

1999 ◽  
Vol 591 ◽  
Author(s):  
P. S. Lee ◽  
D. Mangelinck ◽  
K. L. Pey ◽  
J. Ding ◽  
T. Osipowicz ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Raman Spectroscopy ◽  
Raman Mapping ◽  
Silicide Formation ◽  
Nucleation Sites ◽  
The Difference ◽  
The Stability ◽  
Non Destructive ◽  
Thermal Stability Of

ABSTRACTThe formation and thermal stability of Ni- and Ni(Pt) silicide on narrow polycrystalline Si (poly-Si) lines have been investigated using the non-destructive micro-Raman technique. The presence of Ni or Ni(Pt)Si on poly-Si lines with linewidths ranging from 0.5 gtm to 0.25 μm has been monitored by a distinct Raman peak at around 215 cm−1. Ni(Pt)Si was clearly identified to be present up to a RTA temperature of 900°C on narrow poly-Si lines as compared to pure NiSi which was found only up to 750°C. Raman scattering from the 100×100 μm2 poly-Si pads showed the formation of NiSi2 at 750°C for pure Ni-salicidation and 900°C for Ni(Pt)-salicidation respectively. The difference in the stability of NiSi on the poly-Si pads and lines is discussed in terms of agglomeration, inversion and/or nucleation of NiSi2that could be due to difference in nucleation sites and/or stress. In addition, a correlation between the line sheet resistance and the presence of Ni silicide was found using micro-Raman mapping along single poly-Si lines.

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