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Thermodynamics of Addition Polymerization Processes
Author(s) -
Ivin K. J.
Publication year - 1973
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.197304871
Subject(s) - monomer , polymerization , polymer chemistry , polymer , copolymer , supercooling , chemistry , halogen , alkyl , thermodynamics , materials science , organic chemistry , physics
The polymerizability of compounds such as 1,l‐disubstituted ethylenes, aldehydes, ketones, isocyanates, and five‐ and six‐membered ring compounds is determined largely by thermodynamic considerations. The transition from non‐polymerizability to polymerizability, correspondlng to a change in the sign of ΔG, is often quite sharp. Factors which generally make the free energy of polymerization more negative, and which therefore favor polymerization, are low temperature, high pressure, and high monomer concentration. Additional driving force is sometimes available if the monomer is in the supercooled (glassy) state rather than the crystalline state, or if the polymer crystallizes on formation. Alkyl substituents have an unfavorable effect on polymerizability; halogen substituents have a favorable effect. Many monomers which do not homopolymerize for thermodynamic reasons will copolymerize with a second monomer to the extent of forming copolymers containing 50 or even 66 mol per cent of the first monomer.