Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/67574
Title: Synthesis and performance of new bifunctional stabilizers
Authors: Liu, N.
Pan, J.-Q. 
Lau, W.W.Y. 
Issue Date: Nov-1998
Source: Liu, N.,Pan, J.-Q.,Lau, W.W.Y. (1998-11). Synthesis and performance of new bifunctional stabilizers. Polymer Degradation and Stability 62 (2) : 307-314. ScholarBank@NUS Repository.
Abstract: Six new bifunctional stabilizers have been synthesized by a two-step controlled isocyanation. In the first step a compound containing a stabilizing functional group, 2,4-dihydroxy benzophenone (DHBP) or 2,2,6,6-tetramethyl-4-piperidinol (TMP), reacts with toluene-2,4-diisocyanate (TDI) or hexamethylene diisocyanate (HMDI) at a mole ratio of 1 to 1 to form an intermediate I. In the second step I was directly added to another compound containing a different stabilizing functional group such as TMP or 2,6-di-tert-butyl-4-hydroxy methyl phenol (DBHMP) at a 1 to 1 mole ratio at a given temperature in the presence of dibutyltin dilaurate (DBTDL) catalyst. These six new stabilizers are 2-hydroxy-4-benzophenonyl, 2,2,6,6-tetramethyl-4-piperidinyl hexamethylene dicarbamate (A, MW = 540); 2-hydroxy-4-benzophenonyl, 3,5-di-tert-butyl-4-hydroxyl benzyl hexamethylene dicarbamate (B, MW = 619); 3,5-di-tert-butyl-4-hydroxyl benzyl, 2,2,6,6-tetramethyl-4-piperidinyl hexamethylene dicarbamate (C, MW = 562); 2,2,6,6-tetramethyl-4-piperidinyl, 2-hydroxy-4-benzophenonyl toluene 2,4-dicarbamate (D, MW = 546); 3,5-di-tert-butyl-4-hydroxyl benzyl, 2-hydroxy-4-benzophenonyl toluene 2,4-dicarbamate (E, MW = 625) and 3,5-di-tert-butyl-4-hydroxyl benzyl, 2,2,6,6-tetramethyl-4-piperidinyl toluene 2,4-dicarbamate (F, MW = 568). Their structures have been characterized by IR, NMR, UV and elemental analysis. The photostabilizing and thermal stabilizing effectiveness of these new stabilizers for polypropylene (PP) had been examined. Experimental results show that these new bifunctional stabilizers are effective in protecting PP against photo-oxidation and thermal-oxidation. The effectiveness in relation to the structures of these new bifunctional stabilizers is discussed. © 1998 Elsevier Science Limited. All rights reserved.
Source Title: Polymer Degradation and Stability
URI: http://scholarbank.nus.edu.sg/handle/10635/67574
ISSN: 01413910
Appears in Collections:Staff Publications

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