Mass spectroscopy analysis of volatile photoproducts in photooxidation of polypropylene

Philippart, Jean‐Louis; Posada, Fabrice; Gardette, Jean‐Luc

doi:10.1016/0141-3910(95)87010-5

Cited by 85 publications

(35 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These new broad absorption bands in the carbonyl and hydroxyl region belong to the formation of photo-oxidation products such as carboxyl acid, hydroperoxide and alcohols as it have been identified previously [4,9].…”

Section: Resultsmentioning

confidence: 99%

“…Most of the photoproducts which appear during irradiation, as a consequence of the presence of chromophoric impurities and/or catalytic residues [26], consisting in the formation of hydroperoxy/hydroxyl species and various carbonyl species (carboxylic acid, esters, peresters, lactones in the region 1800-1600 cm -1 ) were identified [1,4,9].…”

Section: Resultsmentioning

confidence: 99%

“…For instance, the photo-oxidative degradation of polyolefin homopolymers has been extensively studied and reported in numerous publications [1][2][3][4][5][6][7][8][9]. In order to extend their lifetime against photo-oxidative degradation, among sterically hindered amine light stabilizers (abbrev.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of sterically hindered N-alkoxyamines on photooxidative stability of reinforced polypropylene

Enescu

Frache

2012

E-Polymers

View full text Add to dashboard Cite

Abstract:In the present paper the influence of Flamestab ® NOR TM 116 (abbrev. FNOR), a sterically hindered N-alkoxyamine stabilizer, on the photo-oxidative stability of calcium carbonate reinforced polypropylene (abbrev. CCPP) used for production of plastic collars has been investigated. The samples, prepared by melt compounding, were exposed to artificial accelerated photo-ageing carried out at λ>300 nm and 45 o C in air. FT-IR and UV-VIS analysis revealed that the deterioration of neat CCPP takes place very rapidly in comparison with the composites containing FNOR. Hydroperoxides and various carbonyl species are formed as the main degradation products during the photo-oxidation process. Moreover, the intensity of the absorption bands grows with increasing of UV exposure time indicating that the material suffers a photo-oxidative degradation process. Indeed, addition of only 0.1 wt.-% FNOR did not significantly modify the length of the induction period of neat CCPP, but a strong efficiency was obtained by increasing the amount of FNOR (0.5 wt.-%) which shows an increase of eight times more as compared with neat CCPP. Therefore, it may be supposed that OIT is linked to the level of concentration of the stabilizer. This remarkable increase in composite stability demonstrated by a lengthening of OIT is typical for sterically hindered N-alkoxyamine stabilizers since they are very efficient at scavenging freeradicals formed as the polymer degrades. In other words, these UV stabilizers are converted to nitroxide radicals (see Scheme 1) which readily trap the polymer degradation species to produce alkoxyamines. Then, the formed alkoxyamines do subsequently react with peroxy radicals to regenerate the active nitroxide radical, thereby this process (called Denisov cycle) proceed in a regenerative cycle, thus retarding oxidative polymer degradation. The increase of absorbance in the carbonyl region as a function of irradiation time was used to determinate the photooxidation rate. It was found out that the photooxidation rate measured from the slope of linear part of the curves is significantly decreased for the CCPP/FNOR0.5 composite compared to neat CCPP. In the light of the above mentioned findings, FNOR could be taken into consideration as an UV stabilizer for CCPP.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Effects of sterically hindered N-alkoxyamines on photooxidative stability of reinforced polypropylene

Enescu

Frache

2012

E-Polymers

View full text Add to dashboard Cite

show abstract

“…A comparison of Figs 7 and 8 with Fig. 3 shows that direct volatilization is very low beyond 100 h of ®ltered, mercury arc exposure except for HCl, despite the signi®cant levels of compounds which can be thermally desorbed from surface powder, even after 52000 h. This could be explained by changes in PVC surface permeability.`Pure' PVC has a low diusivity for O 2 and >10 4 times lower values for small organic molecules. 17 For O 2 and other, small molecules, permeability can be expected to drop even lower as a result of surface crosslinking.…”

Section: Direct Volatilizationmentioning

confidence: 99%

Volatiles release from photodegrading, pigmented PVC: kinetic changes

Carlsson

Krzymien

Pleizier

et al. 1998

Polymer Degradation and Stability

View full text Add to dashboard Cite

Volatile species produced during the ultraviolet irradiation of a rigid, poly(vinyl chloride) construction panel have been established as a function of irradiation time. Residual organic and chloroorganic compounds were detected in the polymer surface after irradiation. Similar species are also directly released during irradiation. In both cases, these were identi®ed and quanti®ed by gas chromatography, with mass spectrometry detection. Rates of volatilisation of organic and chloroorganic compounds were measured directly during accelerated exposure conditions and dropped sharply with irradiation time. This drop may be attributable to the cross-linking of the irradiated surface which becomes chlorine de®-cient and rich in titanium dioxide pigment (rutile). In contrast, samples exposed to sunlight did not undergo surface cross-linking but did thermally desorb volatiles similar to laboratory exposed samples. Crown

show abstract

“…The scavenging of alkyl and peroxy radicals formed during polymer degradation by nitroxyl radicals is considered the usual mechanism by which HALS inhibits polymer oxidation. The structure of these amines is altered when exposed to UV radiation and in the presence of oxygen, producing nitroxyl radicals [5][6][7][8][9][10] . However the HALS stabilization mechanisms can be more complex and involve the quenching of excited polymer-oxygen complexes by HALS-oxygen and the formation of charge-transfer complexes (CTC) between peroxy radicals and HALS [11][12][13][14] .…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Copolymers from Hindered Amines and Vinyl Monomers

Chinelatto¹,

Agnelli²,

Canevarolo³

2014

Polímeros

View full text Add to dashboard Cite

New copolymers from hindered amines and vinyl monomers were synthesized by radical chain polymerization. To obtain polymeric HALS, acrylamide-(1ATP) and acrylate-(4ATP) monomers, derivatives from 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethyl-4-piperidinol were synthesized. The radical chain polymerization of 1ATP with styrene (Sty) using 1-butanethiol (BTN) resulted in a copolymer with 95 units of Sty and 15 units of 1ATP. The radical chain polymerization of 1ATP and vinyl acetate (VAc) has produced only 1ATP homopolymer. In the chain polymerization of 4ATP with Sty or VAc, the hydrogen atom bonded to the nitrogen of 4ATP is labile enough to originate another radical at this site. The steric hindrance imposed by methyl groups on this bonding site hampers its reaction with other propagating species and the formation of a copolymer or network structure will be dependent on the size of the pendent group in the vinyl monomer.

show abstract

Mass spectroscopy analysis of volatile photoproducts in photooxidation of polypropylene

Cited by 85 publications

References 6 publications

Effects of sterically hindered N-alkoxyamines on photooxidative stability of reinforced polypropylene

Effects of sterically hindered N-alkoxyamines on photooxidative stability of reinforced polypropylene

Volatiles release from photodegrading, pigmented PVC: kinetic changes

Synthesis and Characterization of Copolymers from Hindered Amines and Vinyl Monomers

Contact Info

Product

Resources

About