Thermal degradation kinetics of para‐substituted poly (styrene peroxide)s in solution

De, Priyadarsi; Chattopadhyay, Sujay; Madras, Giridhar; Sathyanarayana, D. N.

doi:10.1002/app.11032

Cited by 9 publications

(8 citation statements)

References 11 publications

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“…Activation energies accounting for the decomposition of peroxidic structures have been obtained and published for various macromolecular peroxides. The values range between 120 and 160 kJ/mol [18].…”

Section: H 2 ) N a 19mentioning

confidence: 99%

In Situ Kinetics Study of the Accelerated Aging of Poly(ethylene oxide) Using PhotoDSC

et al. 2006

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PhotoDSC has been applied to follow the global kinetics of chain scissions resulting from the UV light irradiation or from the thermal degradation of a high molecular weight PEO (4 x 10(6) g x mol(-1)). Infrared spectroscopy, XRD measurements and rheology experiments were performed to evidence the occurrence of chain scissions. Melting energy was used as a tool to quantify the extent of the degradation. It was found that the chain scissions reaction follows a first-order kinetic law for both photo and thermal degradation. The activation energies were found identical in both cases (41 kJ x mol(-1)), whereas the degradation rate was higher in the case of UV irradiation than in the case of thermoageing.

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Section: H 2 ) N a 19mentioning

confidence: 99%

In Situ Kinetics Study of the Accelerated Aging of Poly(ethylene oxide) Using PhotoDSC

et al. 2006

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“…The peak at m / z = 403 is assigned to the 4-formylphenyl stearate, which is formed by the degradation of weak peroxy bonds (Scheme ). Main-chain O–O bond breaking is considered as the major reason behind the formation of all of the molecular ion peaks, following the chain unzipping mechanism . Also, the PVBPP (Figure S16 and Table S2) and PVBCRP (Figure S17 and Table S3) displayed degradation similar to that of PVBSP.…”

Section: Resultsmentioning

confidence: 97%

Degradable Crystalline Polyperoxides from Fatty Acid Containing Styrenic Monomers

et al. 2018

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Vinyl polyperoxides, alternating copolymers of vinyl monomers and molecular oxygen, are highly viscous amorphous materials because of the flexible peroxy (−O− O−) bonds in the main chain. In this study, crystalline polyperoxides have been synthesized by oxidative radical polymerization of styrenic monomers having fatty acid moieties attached to the phenyl ring using molecular oxygen at 100 psi pressure. Determination of active oxygen contents in polyperoxides, 13 C NMR spectroscopy, and electron impact mass spectroscopy (EI-MS) confirmed alternating placement of −O−O− bonds after every styrenic monomer unit in the copolymer main chain. Thermal stability was studied by thermogravimetric analysis (TGA). Exothermic degradation of these polyperoxides was observed by differential scanning calorimetry (DSC), and degradation products have been identified from EI-MS study. DSC and powder X-ray diffraction (PXRD) studies revealed crystallinity in the polyperoxides with fatty acids having 12 carbon atoms or longer. This crystalline behavior was further supported by polarized optical microscopy (POM), where a birefringence texture which is characteristic of semicrystalline polymer was formed for polyperoxides with C ≥ 12 of the side-chain alkyl carbons. Transmission electron microscopy (TEM) was used to define the thickness and crystal structure of the polymers. Theoretical studies have been performed using density functional theory (DFT) to support the experimental interlamellar distance from X-ray diffraction studies.

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“…Different types of molecular structures with different molecular weights were generated because of the degradation of the polymers, listed in Table and Table S1. All the fragments (Figure ) were obtained through the cleavage of labile ‐O‐O‐ bonds in the main chain, followed by chain unzipping mechanism . The peak appeared at m / z = 403, attributed to the 4‐formylphenyl stearate (coming from VBS unit) fragment of CPVBM3 and the other important peak at m/z = 71 is for the CH 3 COCO (appearing from MMA unit).…”

Section: Resultsmentioning

confidence: 99%

“…All the fragments (Figure 4) were obtained through the cleavage of labile -O-O-bonds in the main chain, followed by chain unzipping mechanism. [39] The peak appeared at m/ z = 403, attributed to the 4-formylphenyl stearate (coming from VBS unit) fragment of CPVBM3 and the other important peak at m/z = 71 is for the CH 3 COCO (appearing from MMA unit). Apart from that, the dissociation of benzyl stearate unit occurs through C-O and C-C bond scission which generates several stable linear compounds.…”

Section: Thermal Degradation Of Copolyperoxidesmentioning

confidence: 99%

Composition‐dependent crystallization behavior of copolyperoxides from methyl methacrylate and 4‐vinylbenzyl stearate

Mete

Goswami

2020

Journal of Polymer Science

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To study the composition‐dependent crystallization behavior of copolyperoxides, herein a series of copolymers were prepared by varying the ratios of methyl methacrylate (MMA) and 4‐vinylbenzyl stearate (VBS) under 100 psi oxygen pressure using AIBN as an initiator at 50°C in toluene. Both 13C NMR and electron impact mass spectroscopy (EI‐MS) approved an alternative placement of either of the monomer and peroxy (–O–O–) links throughout the polymer chain. Thermal stability of the resulting copolyperoxides was investigated by thermogravimetric analysis (TGA) and the degradation fragments have been recognized from EI‐MS study. In addition, differential scanning calorimetry (DSC) displayed an endothermic peak as well as an exotherm associated with the melting of the side chain crystalline domains and degradation of –O–O– links in the polymer main chain, respectively. Furthermore, DSC thermograms unveiled a systematic decrease of the crystalline melting temperature (Tm) with the enhancement of MMA content in the copolymers. Small angle X‐ray scattering (SAXS) revealed the existence of lamellar morphology (depends on VBS content in the copolyperoxide) in the synthesized polyperoxide materials, further supported by atomic force microscopy (AFM) analysis showing a layered fibrillar assembly with multiple heights of the lamella. The significant crystalline nature of the polyperoxides was further evidenced from the appearance of lattice fringes in the transmission electron microscope (TEM) micrographs. The crystalline morphology with birefringent texture was further evidenced from the polarized optical microscopy (POM) study. Thus, the present study reported the effective variation of crystalline behavior in copolyperoxide materials with the incorporation of MMA units in the copolyperoxide chains.

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Thermal degradation kinetics of para‐substituted poly (styrene peroxide)s in solution

Cited by 9 publications

References 11 publications

In Situ Kinetics Study of the Accelerated Aging of Poly(ethylene oxide) Using PhotoDSC

In Situ Kinetics Study of the Accelerated Aging of Poly(ethylene oxide) Using PhotoDSC

Degradable Crystalline Polyperoxides from Fatty Acid Containing Styrenic Monomers

Composition‐dependent crystallization behavior of copolyperoxides from methyl methacrylate and 4‐vinylbenzyl stearate

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