Thermal Degradation of Polyoxymethylene Evaluated with FTIR and Spectrophotometry

Ramirez, Narciso Vilà; Sánchez‐Soto, Miguel; Illescas, S.; Gordillo, Antonio

doi:10.1080/03602550902725472

Cited by 27 publications

(11 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is understood that POM degradation is initiated either by bond dissociation at the chain end (-OH groups), or by random main-chain scission for the end-capped polymer followed by unzipping [29,30]. If the hydroxylic groups of POM are not blocked, rapid depolymerization takes place at moderate temperatures by a zipper mechanism yielding the monomer again [31]. Moreover, the reason for the lower thermal stability of POM/HAp nanocomposites is also the high sensitivity of the POM main chain to attack by base under heating.…”

Section: Resultsmentioning

confidence: 99%

The influence of molecular weight on the properties of polyacetal/hydroxyapatite nanocomposites. Part 2. In vitro assessment

Pielichowska

2012

J Polym Res

View full text Add to dashboard Cite

A series of polyoxymethylene (POM)/hydroxyapatite (HAp) nanocomposites for long-term bone implants were prepared by melt processing using POM with different molecular weight. Bioactivity was examined by incubating the samples in simulated body fluid. Moreover, in vitro stability, wettability, thermal stability, and formaldehyde release process were investigated. Results of in vitro investigations show that an increase in HAp content in POM nanocomposites facilitates the formation of an apatite layer on the sample surface. There is no significant influence of HAp concentration on the contact angle values as revealed by wettability studies. Thermogravimetric analysis results indicate that with an increase in HAp content the thermal stability of POM matrix decreases significantly depending upon the POM molecular weight. Finally, it was found the amount of formaldehyde leached out of the samples during the incubation period depends on the HAp content: amounts in excess of 3 ppm were emitted for the samples containing only 10% HAp.

show abstract

Section: Resultsmentioning

confidence: 99%

The influence of molecular weight on the properties of polyacetal/hydroxyapatite nanocomposites. Part 2. In vitro assessment

Pielichowska

2012

J Polym Res

View full text Add to dashboard Cite

show abstract

“…It is assumed that the formation of the initiating system is accompanied by the opening of the S 8 ring as a result of a nucleophilic attack by a dimethylphosphate anion (Scheme 1). At least, ionic liquids that do not contain a dimethylphosphate anion (and its homologs) did not interact with S 8 , and the opening of the S 8 ring when interacting with dimethylphosphate-containing ionic liquids was confirmed earlier by high-resolution mass spectroscopy data and the appearance of an additional oxygen atom signal in the 17 O NMR spectra (10)(11)(12).…”

Section: Methodsmentioning

confidence: 70%

The product of interaction of elemental sulfur and dimethylphosphate 1,3-dimethylimidazolium is a new green initiator of formaldehyde polymerization

Tarasova

Zanin

Krivoborodov

et al. 2021

Green Chemistry Letters and Reviews

View full text Add to dashboard Cite

Interaction of 1,3-dimethylimidazolium dimethylphosphate and elemental sulfur synthesized a new initiator of polymerization of formaldehyde, opening the possibility of its implementation in accordance with the principles of Green chemistry. The possibility of fast oligomerization of formaldehyde in an aqueous medium with the formation of insoluble products, the structure of which is determined by FTIR, MALDI-TOF, 1 H NMR, 13 C NMR, HSQC and HMBC spectroscopy, is shown. It was found that (phosphonooxy-)oligosulfanide anion initiates formaldehyde oligomerization by anionic mechanism with chain termination due to interaction with water. It was shown that the synthesized formaldehyde oligomers retain resistance to degradation up to a temperature of 443 K, and then slowly thermally decompose to a temperature of 513 K, above which the rate of thermal degradation increases significantly.

show abstract

“…In this region, no new bands were detected, hence no degradation was detected. Figure 9B presents the 1473‐1462 cm −1 bands of CH 2 bending of the POM and paraffin 34,35 and the 1434‐1383 cm −1 bands of CH 3 and the 1237 cm −1 band COC bending are associated to the POM 47,48 . Also, a low‐intensity extra band around the 1741 cm −1 is detected, due to the presence of a carbonyl group, meaning that some oxidation took place during cycling or the shaping process 48 .…”

Section: Resultsmentioning

confidence: 99%

“…Figure 9B presents the 1473‐1462 cm −1 bands of CH 2 bending of the POM and paraffin 34,35 and the 1434‐1383 cm −1 bands of CH 3 and the 1237 cm −1 band COC bending are associated to the POM 47,48 . Also, a low‐intensity extra band around the 1741 cm −1 is detected, due to the presence of a carbonyl group, meaning that some oxidation took place during cycling or the shaping process 48 . Figure 9C shows the asymmetric and symmetric bands of skeletal stretching of COC at 1089, 932 and 902 cm −1 , the CH 2 rocking vibration at 730‐719 cm −1 and the OCO bending at 632 cm −1.…”

Section: Resultsmentioning

confidence: 99%

New shape‐stabilized phase change materials obtained by single‐screw extruder

et al. 2021

View full text Add to dashboard Cite

Shape‐stabilized phase change materials (SS‐PCM) are promising materials given their potential to control leakage of liquid PCM. However, SS‐PCM still has low thermal conductivity and high flammability, which are important properties for several applications, such as the thermal indoor comfort in buildings. In this study, two new polymeric SS‐PCM were developed and their properties were optimized by the use of different additives. Both high‐density polyethylene (HDPE) and polyoxymethylene (POM) work as matrix materials and MPCM 28 from Microtek acts as PCM. Besides, the graphite was used as an additive material to increase the thermal conductivity, and the magnesium hydroxide to minimize flammability of the composite. Both inorganic fillers also help in the PCM dispersion within the matrix. To evaluate the effect of each component, seven formulations were manufactured by a single screw extruder and a set of characterization (Differential scanning calorimetry, Thermogravimetric analyses, for thermophysical evaluation, and dynamical mechanical analyses, for thermomechanical evaluation over 1000 thermal cycles was performed. The main outputs of the investigation are the proposed formulations that have a good fire reaction performance, whereas their thermal and chemical stability are guaranteed up to 1000 cycles. The HDPE samples present around 12 kJ/kg melting enthalpy when 10 wt% microencapsulated PCM is included in the formulation. In addition, the POM samples present around 7.5 kJ/kg when 10 wt% microencapsulated PCM is included in the formulation. For all formulations, the melting enthalpy obtained is around 27.5°C, in concordance with the reported by the manufacturer.

show abstract

Thermal Degradation of Polyoxymethylene Evaluated with FTIR and Spectrophotometry

Cited by 27 publications

References 10 publications

The influence of molecular weight on the properties of polyacetal/hydroxyapatite nanocomposites. Part 2. In vitro assessment

The influence of molecular weight on the properties of polyacetal/hydroxyapatite nanocomposites. Part 2. In vitro assessment

The product of interaction of elemental sulfur and dimethylphosphate 1,3-dimethylimidazolium is a new green initiator of formaldehyde polymerization

New shape‐stabilized phase change materials obtained by single‐screw extruder

Contact Info

Product

Resources

About