Synthesis of new polymeric hindered amine light stabilizers: Performance evaluation in styrenic polymers

Polymeric hindered amine light stabilizers (HALSs), in which the HALS functionality was attached to the terminal isocyanate chain end of poly(styryl-co-styryl isocyanate), were synthesized by a two-step process. First, cinnamoyl azide was prepared and copolymerized with styrene by a free-radical copolymerization method. Polymeric low-molecular-weight and high-molecular-weight 2,2,6,6-tetramethyl-4-pipridinol-graft-poly(styryl-co-styryl isocyanate) and 4-amino-2,2,6,6-tetramethyl piperidine-graft-poly(styryl-co-styryl isocyanate) were synthesized by a grafting method. The photodegradation and stabilization of different grades of high-impact polystyrene (HIPS) were studied at 55°C in air at different time intervals, and the photostabilizing efficiency of polymeric HALSs was compared with conventional light stabilizers, such as 2,2,6,6-tetramethyl-4-pipridinol and bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate. Polymeric HALSs showed significant improvements in the photostabilization of HIPS. The solubility and diffusion coefficient of polymeric HALSs were studied. The morphological changes in HIPS caused by photooxidation were also studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1126–1138, 2003

[1]  J. Lacoste,et al.  Polybutadiene content and microstructure in high impact polystyrene , 1996 .

[2]  J. Lemaire,et al.  Chain‐scission and yellowing in high impact polystyrene , 1995 .

[3]  J. Lemaire,et al.  Photo‐ and thermoinitiated oxidation of high‐impact polystyrene. I. Characterization by FT‐IR spectroscopy , 1994 .

[4]  J. Lacoste,et al.  Photoinitiated oxidation of heterophasic ethylene–propylene copolymers. I. Comparison of oxidation products , 1993 .

[5]  R. Singh,et al.  Degradation and stabilization of ethylene-propylene copolymers and their blends: A critical review , 1991 .

[6]  A. Hult,et al.  Surface modification of polymers. IV. UV initiated degradation of polymers with stabilizers grafted onto the surface , 1989 .

[7]  F. Gugumus.  Advances in the stabilization of polyolefins , 1989 .

[8]  Hu Xingzhou,et al.  Photo-stabilization of polypropylene film by surface photo-grafting , 1987 .

[9]  J. Moisan.  Effects of Oxygen Permeation and Stabiliser Migration on Polymer Degradation , 1985 .

[10]  J. Moisan.  Diffusion des additifs du polyethylene—I: Influence de la nature du diffusant , 1980 .

[11]  A. Ghaffar,et al.  Photo-oxidation of high impact polystyrene—III. The mechanism of the cross-linking reaction , 1977 .

[12]  D. Kohn,et al.  Polymers with pendant isocyanate groups. I. Dual synthesis and properties of poly(styrene‐co‐styryl isocyanate) , 1976 .

[13]  R. Roe,et al.  Solubility and diffusion coefficient of antioxidants in polyethylene , 1974 .

[14]  H. Bair.  Exudation of an antioxidant additive from thin polyethylene films , 1973 .

[15]  D. Carlsson,et al.  Photooxidation of Polypropylene Films. IV. Surface Changes Studied by Attenuated Total Reflection Spectroscopy , 1971 .

[16]  D. Carlsson,et al.  Surface changes during the photo‐oxidation of polypropylene , 1970 .

[17]  H. Keskkula,et al.  Heterogeneous polymer systems. IV. Mechanism of rubber particle formation in rubber‐modified vinyl polymers , 1966 .