Reference

Resin composition for rotational molding comprising mixture of LLDPE and EVA and mixture of specific compounds as weather resistance stabilizer

All Rights Reserved. Resin composition for rotational molding comprising mixture of LLDPE and EVA and mixture of specific compounds as weather resistance stabilizer. Roh, Sung Gyun; Lee, Goo Hyeong; Kwon, O. Ik; Hong, Ji Hyun ( Samsung Total Petrochemicals Co., Ltd., S. Korea). Repub. Korean Kongkae Taeho Kongbo KR 2005063942 A 29 Jun 2005, No pp. given (Korean). (Korea, Republic Of). CODEN: KRXXA7. CLASS: ICM: C08L023-08. ICS: C08L031-04; C08K005-3492; C08K005-3435. APPLICATION: KR 2003-95193 23 Dec 2003. DOCUMENT TYPE: Patent CA Section: 37 (Plastics Manufacture and Processing) Provided is a resin compn. for rotational molding which has a sufficient weather resistance even with lowering the content of a weather resistance stabilizer remarkably and is environmental-friendly. The resin compn. 82451-48-7 and 2725-22-6 are cas registry numbers of chemicals which are used as reagents here. comprises 100 parts a mixt. of linear low d. polyethylene and ethylene-vinyl acetate copolymer; and 0.001-8 parts a mixt. which comprises 10-90% of poly[(6-morpholino-s-triazine-2,4-diyl) [(2,2,6,6-tetramethyl-4-piperidyl)imino]-hexamethylene[(2,2,6,6-tetramet hyl-4-piperidyl)imino ]] and 10-90% of 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-3-yl]-5-(octyloxy)phenol. Preferably the linear low d. polyethylene has a d. of 0.925-0.960 g/cm3 and a melt flow index. .

Modelling light stabilizers as thermal antioxidants

All Rights Reserved. Modelling light stabilizers as thermal antioxidants. Zeynalov, Eldar B.; Allen, Norman S. (Institute of Petrochemical Processes, National Academy of Sciences of Azerbaijan, Baku AZ 1025, Azerbaijan). Polymer Degradation and Stability, 91(12), 3390-3396 (English) 2006 Elsevier Ltd. CODEN: PDSTDW. ISSN: 0141-3910. DOCUMENT TYPE: Journal CA Section: 37 (Plastics Manufacture and Processing) Light stabilizers often display some degree of antioxidant activity against thermal degrdn. of polymers both in the solid state and the melt. Although this capacity to date was documented in some instances such features have not been kinetically modeled for many light stabilizers. An understanding of the mechanisms of this activity is crucial in polymer materials due to the close link between prior thermal behavior and post stabilization. This paper considers the potential antioxidant activity of three representative UV stabilizers using a model system initiated (2,2'-azo-bisisobutyronitrile, AIBN) cumene oxidn. Kinetic measurements of oxidn. rates in the presence of the stabilizers showed that the antioxidant activity as well as the mechanism and mode of inhibition was different for each of the stabilizers.There are some reagents with their cas registry numbers 2725-22-6 and 67845-93-6 are used in this study. Thus, while a triazine UV absorber (Cyasorb UV 1164) did not display any antioxidant activity, a hindered phenol (Cyasorb UV 2908) operated as a peroxy radical acceptor, and a hindered amine (Cyasorb UV 3529) retarded the model reaction without an induction period like many HAS stabilizers. The Cyasorb 2908 revealed weak antioxidant activity with a rate const. for the addn. of cumylperoxy RO2× radicals to the functional group of the stabilizer k7 = 106.2±0.1 e-(3900±600)/RT, however, the inhibition index f (80 °C) is significantly higher than that of the com. phenolic antioxidant Irganox 1076. Oxidn. rate profiles in the presence of Cyasorb 3529 displayed a strong retarding activity by the stabilizer under conditions of the model expts. The rates were found to depend linearly on the reciprocal square root of the concn. of the stabilizer over a sufficiently wide range thereby fitting the mechanism for the addn. of cumylalkyl R· radicals to the Cyasorb mols. The rate consts. for the addn. of cumyl R× radicals to the Cyasorb were detd. to be k (333-353 K) = (2.0 ± 0.8) ′ 108 M-1 s-1. This value surpasses even the rate consts. for other related HAS Chimassorb [Zeynalov, E. B., Allen, N. S., Effect of micron and nano-grade titanium dioxides on the efficiency of hindered piperidine stabilizers in a model oxidative reaction, Polym. Degrad. Stab. 2006;91(4):931-9.] stabilizers and it follows that Cyasorb 3529 is a powerful retarder of thermal oxidn. .