Flexibilized styrene-N-substituted maleimide copolymers. II. Multiblock copolymers prepared from PTHF-based iniferters

Abstract

This article describes the synthesis and molecular characterization of thermal polymeric iniferters, based on hydroxy‐terminated poly(tetrahydrofuran) (PTHF), bearing thiuram disulfide groups along the chain. Thermal polymerization after the addition of styrene (S) and N‐methylmaleimide (MI) to these PTHF‐based polymeric iniferters yielded segmented PTHF (SMI‐block‐PTHF)n block copolymers that proved to have a single Tg. The multiblock copolymers were molecularly characterized by elemental analysis, IR, and NMR. The thermal stability, as checked by thermogravimetric analysis, proved to be good up to about 350 °C. A size exclusion chromatography/differential viscosity (DV) analysis showed that the molecular weights of the synthesized single‐phase multiblock copolymers were sufficiently high (several times the estimated molecular weight between two adjacent entanglements) to determine the entanglement density from the rubbery plateau modulus, for which the method developed by S. Wu (J Polym Sci Part B: Polym Phys 1989, 27, 723–741) was applied. The entanglement density of flexibilized SMI proved to be about 20–25% higher than that of the nonflexibilized SMI. This increase is disappointing, and more work, based on the described concept, is required to achieve the desired enhancement of the toughness. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3558–3568, 2000

A novel tertiary bromine-functionalized thermal iniferter for controlled radical polymerization

“…Iniferters can be classified as photoiniferters and thermal iniferters. Photoiniferters are mainly N,Ndiethyldithiocarbamyl group-bearing compounds, 9-12 whereas thermal iniferters, apart from phenylazotriphenylmethane, 13 are usually carbon-carbon labile bond-containing compounds, such as tetraphenylsuccinodinitrile, 14 hydroxy-2-(p-tolylaminocarbonyloxy)-1,1,2, 2-tetraphenylethane, 15 tetra(p-methoxy phenyl) succinodinitrile, 16 pentaphenylethane, 16 1,1,2,2-tetraphenyl-1,2-bis(trimethylsilyloxy)-ethane 17 and 1,1,2,2-tetraphenyl-1,2-bis(phenoxy)-ethane. 18 1,1,2,2-Tetraphenyl-1,2-ethanediol (TPED) has also been used as a radical initiator, but it does not proceed via the CRP mechanism 19,20 due to the occurrence of a side reaction during the initiation of the monomer.…”

Studies of silicon-containing maleimide polymers. Part II: Synthesis and properties of poly(styrene-co-brominecontaining maleimide).

“…A lot of work about the AM copolymers, such as the copolymers with styrene [20][21][22], has been reported so far. These copolymers were synthesized by introducing the rigid and high thermal stability of AM segment leading to higher softening points (or T g ) and good fire resistance.…”

Studies of novel copolymers for deep‐UV photoresists. I. Synthesis and properties of poly(styrene‐co‐silicon‐containing maleimide)

“…N ‐aryl maleimide (AM) monomers, such as N ‐phenyl maleimide (PM), N ‐hydroxyphenyl maleimide (HPM), and halide‐substituted N ‐hydroxyphenyl maleimide (XHPM), were usually copolymerized with ethylene or propylene series monomers to promote their heat and fire resistance. Many researches on the AM copolymers, such as the copolymers with styrene,14–16 methyl methacrylate,17–19 acrylonitrile,20 or vinyl acetate,21 have been reported so far.…”