- Email: [email protected]
Photoprotecting behaviour of a phenylformamidine light stabilizer
August 1992
Additives for Polymers
Oxidation of polythene stabilized with monophenol antioxidant
Oxidation of HDPE at 200”, containing the antioxidant 2,6-di -tert-butyl-phenylphenol (monophenol) has been investigated. Monophepol is a weak antioxidant, and in its presence the induction period is low and is linearly dependent on the concentration of antioxidant, the latter being consumed at a constant rate. The initial rate of absorption of O2 reduces rapidly and increases slowly with low and high concentrations of monophenol, respectively, whereas during the course of a separate test, it slowly increased with the time of oxidation. Conclusions concerning the low effectiveness of monophenols in comparison with biphenols drawn from previous studies of the oxidation of PP have been confirmed. (9 refs). Int. Poly. Sci. & Tech., 1992, 19, (2) TIOI-105 (Translated
from: Vysokomolekulyarnye Soedineniya, Kratkie Soobshcheniya,1991 (12) 899) Photodegradation of polythene Thin polyethylene films containing various additives as photoinitiators were photooxidized in natural weathering conditions and under accelerated conditions using xenon radiation at the University of Brussels. The photoinitiators included iron carboxylate, ally1 ether and ester and various aryland aralkylketones. Main chain scission is the main degradation reaction which occurs when polyethylene containing Ir. St. is degraded in natural weathering conditions. This process would result mainly from the decomposition of isolated hydroperoxides. In the presence of other photoinitiators, main chain scission follows disproportionation of peroxy radicals but a few cross-links are also formed. When the xenon arc is used, the spectral distribution of the radiation is very similar to that of the sun, but the temperature is higher. Chain propagation is then favoured, which leads to a higher concentration of P and PO. radicals in clusters and hence to a higher probability of crosslinking. (28 refs). Poly. Degmd. & Stabil., 1992, 37, 233-245
Photoprotecting behaviour of a phenylformamidine light stabilizer
The photoprotecting behaviour and effectiveness of three UV-stabilizers, N-(-p-ethoxy-carbonylphenyl-)-N’-ethyi_N’ phenyl-formamidine(UV1),2-hydroxy-4-octoxy benzophenone (UV2) and 2-(2’hydroxy-3’,5’-ditert-buty;-phenyl)-5chlorobenzotriazole (UV3) have been studied by IR, UV and fluorescence spectroscopies at the Institute of Chemistry, Beijing, China.
o1992 Elsevier Science Publishers Ltd.
Additives for Polymers
August 1992
The photoprotecting effectiveness decreases in the order UV2 > UV 1 > UV3. UV 1 shows a good screening action and is a good quencher of singlet oxygen and of the fluorescence of polypropylene and of rhodamine. The photoprotecting action of UVl may be associated with UV screening, with excited state quenching and with its ability to scavenge free radicals. (12 refs). Poly. Degd.
Degree of impregnation in continuous glass fibre prepregs
& Stabil., 1992, 37, 195-199
A procedure to determine the degree of impregnation from melt-impregnated polypropylene/glass fibre prepreg has been developed in a programme sponsored by the Technology Development Centre, Finland, and four other companies. This paper describes how the prepreg sample is moulded in an embedding agent, ground and coloured with colouring agent penetrating to the space between unimpregnated fibres. The sample is studied with an optical microscope and transillumination is used. Unimpregnated fibres are calculated individually. Moulding the specimens with the embedding agent, grinding and preparing the specimens with colouring agent, postgrinding, study of the specimens and the calculations to determine the degree of impregnation, are described. (8 refs). Polymer Testing, 1992, 11, 215-224
MATERIALS END USE TRADE NAME(S) CHEMICAL TYPE COMPANY
PRODUCT DETAILS
COLOURANTS 1) IRGALITE YELLOW WGP 2) IRGACOLOR YELLOW 10415 1) Unspecified 2) Mixed metal oxides Ciba-Geigy Ltd, Ashton New Road, Clayton, Manchester 4AR, (UK).
Ml 1
Yellow WGP is described as a very green shade yellow toner specifically developed for use in PVC, polyolefins, and sytrenebased polymers. Can also be used in some engineering plastics. Yellow 104 15, developed for use in ABS, nylon 6 and 66, polycarbonate, and other engineering polymers, is claimed to have improved heat resistance compared with other mixed metal oxides of similar hue.
Q1992 Elsevier Science Publishers Ltd.
5
Additives for Polymers
Oxidation of polythene stabilized with monophenol antioxidant
Oxidation of HDPE at 200”, containing the antioxidant 2,6-di -tert-butyl-phenylphenol (monophenol) has been investigated. Monophepol is a weak antioxidant, and in its presence the induction period is low and is linearly dependent on the concentration of antioxidant, the latter being consumed at a constant rate. The initial rate of absorption of O2 reduces rapidly and increases slowly with low and high concentrations of monophenol, respectively, whereas during the course of a separate test, it slowly increased with the time of oxidation. Conclusions concerning the low effectiveness of monophenols in comparison with biphenols drawn from previous studies of the oxidation of PP have been confirmed. (9 refs). Int. Poly. Sci. & Tech., 1992, 19, (2) TIOI-105 (Translated
from: Vysokomolekulyarnye Soedineniya, Kratkie Soobshcheniya,1991 (12) 899) Photodegradation of polythene Thin polyethylene films containing various additives as photoinitiators were photooxidized in natural weathering conditions and under accelerated conditions using xenon radiation at the University of Brussels. The photoinitiators included iron carboxylate, ally1 ether and ester and various aryland aralkylketones. Main chain scission is the main degradation reaction which occurs when polyethylene containing Ir. St. is degraded in natural weathering conditions. This process would result mainly from the decomposition of isolated hydroperoxides. In the presence of other photoinitiators, main chain scission follows disproportionation of peroxy radicals but a few cross-links are also formed. When the xenon arc is used, the spectral distribution of the radiation is very similar to that of the sun, but the temperature is higher. Chain propagation is then favoured, which leads to a higher concentration of P and PO. radicals in clusters and hence to a higher probability of crosslinking. (28 refs). Poly. Degmd. & Stabil., 1992, 37, 233-245
Photoprotecting behaviour of a phenylformamidine light stabilizer
The photoprotecting behaviour and effectiveness of three UV-stabilizers, N-(-p-ethoxy-carbonylphenyl-)-N’-ethyi_N’ phenyl-formamidine(UV1),2-hydroxy-4-octoxy benzophenone (UV2) and 2-(2’hydroxy-3’,5’-ditert-buty;-phenyl)-5chlorobenzotriazole (UV3) have been studied by IR, UV and fluorescence spectroscopies at the Institute of Chemistry, Beijing, China.
o1992 Elsevier Science Publishers Ltd.
Additives for Polymers
August 1992
The photoprotecting effectiveness decreases in the order UV2 > UV 1 > UV3. UV 1 shows a good screening action and is a good quencher of singlet oxygen and of the fluorescence of polypropylene and of rhodamine. The photoprotecting action of UVl may be associated with UV screening, with excited state quenching and with its ability to scavenge free radicals. (12 refs). Poly. Degd.
Degree of impregnation in continuous glass fibre prepregs
& Stabil., 1992, 37, 195-199
A procedure to determine the degree of impregnation from melt-impregnated polypropylene/glass fibre prepreg has been developed in a programme sponsored by the Technology Development Centre, Finland, and four other companies. This paper describes how the prepreg sample is moulded in an embedding agent, ground and coloured with colouring agent penetrating to the space between unimpregnated fibres. The sample is studied with an optical microscope and transillumination is used. Unimpregnated fibres are calculated individually. Moulding the specimens with the embedding agent, grinding and preparing the specimens with colouring agent, postgrinding, study of the specimens and the calculations to determine the degree of impregnation, are described. (8 refs). Polymer Testing, 1992, 11, 215-224
MATERIALS END USE TRADE NAME(S) CHEMICAL TYPE COMPANY
PRODUCT DETAILS
COLOURANTS 1) IRGALITE YELLOW WGP 2) IRGACOLOR YELLOW 10415 1) Unspecified 2) Mixed metal oxides Ciba-Geigy Ltd, Ashton New Road, Clayton, Manchester 4AR, (UK).
Ml 1
Yellow WGP is described as a very green shade yellow toner specifically developed for use in PVC, polyolefins, and sytrenebased polymers. Can also be used in some engineering plastics. Yellow 104 15, developed for use in ABS, nylon 6 and 66, polycarbonate, and other engineering polymers, is claimed to have improved heat resistance compared with other mixed metal oxides of similar hue.
Q1992 Elsevier Science Publishers Ltd.
5