ISSN:
0887-624X
Schlagwort(e):
4-methylene-4H-1,3-benzodioxin-2-one
;
exo-methylene cyclic monomers
;
radical polymerization
;
kinetics
;
monomer reactivity ratios
;
chemical amplification
;
decarboxylation
;
poly[(o-hydroxyphenyl)acetylene]
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
4-Methylene-4H-1,3-benzodioxin-2-one (MBDOON), an α-substituted cyclic styrene derivative, was synthesized and polymerized readily with 2,2′-azobis(isobutyronitrile) (AIBN) as an initiator in solution. The kinetics of the MBDOON homopolymerization with AIBN was investigated in N-methyl-2-pyrrolidone (NMP). The rate of polymerization, Rp, can be expressed by Rp - k[AIBN]0.52[MBDOON]1.1 and the overall activation energy has been calcualted to be 75.7 kJ/mol. Monomer reactivity ratios in copolymerization of MBDOON (M2) with styrene (M1) are r1 = 0.31 and r2 = 3.20, from which Q and e values of MBDOON can be calculated as 3.0 and -0.7, respectively. Ring-substituted MBDOON monomers such as 6-chloro, 6-methyl, and 7-methoxy derivatives were synthesized and polymerized with AIBN. The 6-substituted MBDOON's readily underwent radical polymerization while the 7-methoxy-MBDOON was slower to polymerize. Poly(MBDOON) is predominantly heterotactic. (rr = 35, mr = 46, and mm = 19%). The polymer releases carbon dioxide at about 200°C and is converted with some depolymerization to poly[(o-hydroxyphenyl)acetylene]. The thermolysis temperature is very much affected by the ring substituent. The onset of carbon dioxide liberation was observed at 140°C in the case of the 7-methoxyl derivative while the 6-substituents had a smaller effect on the decarboxylation temperature. © 1993 John Wiley & Sons, Inc.
Zusätzliches Material:
8 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pola.1993.080310728
Permalink
