Back to Search
Start Over
Synthesis, thermal and mechanical properties of benzocyclobutene-functionalized siloxane thermosets with different geometric structures
- Source :
-
European Polymer Journal . Apr2012, Vol. 48 Issue 4, p751-760. 10p. - Publication Year :
- 2012
-
Abstract
- Abstract: A series of benzocyclobutene-functionalized siloxane thermosets were prepared to investigate the relationship between the monomer’s chemical structure and the properties of the corresponding polymer. Monomer 1,1,3,3-tetramethyl-1,3-bis[2′-(4′-benzocyclobutenyl)]vinyldisiloxane (DVS-BCB) and 1,3,5,7-tetramethyl-1,3,5,7-tetra[2′-(4′-benzocyclobutenyl)]vinylcyclotetrasiloxane (CYC-BCB) were synthesized by Heck reaction. Copolymer Poly(DVS-BCB-co-POSS) was obtained through incorporating octavinyl-T8-silsesquioxane (Vinyl-POSS) into DVS-BCB matrix via Diels–Alder reaction. The oligomers, P-DVS-BCB, P-CYC-BCB and P-Poly(DVS-BCB-co-POSS), were obtained by refluxing the mesitylene solution of the BCB monomers at the BCB ring opening temperature. The BCB monomers and oligomers showed a similar curing behavior with an exothermic peak temperature near 260°C. The curing kinetic parameters, the apparent activation energy (E a), the frequency factor (A) and the reaction order (n), were obtained by non-isothermal DSC method. The BCB polymers possessed good thermal stability (T d > 450°C in N2). Due to the highly crosslinked network structure, CYC-BCB polymer exhibited higher glass transition temperature, higher modulus and lower coefficient of thermal expansion than DVS-BCB and Poly(DVS-BCB-co-POSS) polymers. Moreover, the BCB polymers also demonstrated low dielectric constants (<2.8 at 1MHz) and low water absorptions. The films prepared from the BCB oligomer solution showed a well planarization (root-mean-square roughness <0.5nm). [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 00143057
- Volume :
- 48
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- European Polymer Journal
- Publication Type :
- Academic Journal
- Accession number :
- 73767927
- Full Text :
- https://doi.org/10.1016/j.eurpolymj.2012.01.006