0000000000608502
AUTHOR
Liane Lucy De Lucca Freitas
Dynamic mechanical properties of semi-interpenetrating networks based on poly(styrene-co-maleic anhydride): 3. Poly(2,6-dimethyl-1,4-phenylene ether)-cross-poly(styrene-co-maleic anhydride)
Semi-IPN's based on linear poly(2,6-dimethyl-1,4-phenylene ether) (PPE) and diamine crosslinked poly(styrene-co-maleic anhydride) (PScoMA) copolymers containing small amounts of maleic anhydride (PSA=4.7wt.-% MA, PSB=5.8 wt-% MA) are studied with respect to the influence of cross-linking on the phase behavior. Temperature-dependent dynamic mechanical analysis (DMA) and DSC show that the semi-IPN's prepared from concentrated solution show weak crystallinity of the PPE phase. After heating above the PPE melting transition the semi-IPN's remain amorphous and the relaxation in the glass transition region as well as the terminal relaxation of the free PPE chains in the network is studied as a fu…
Dynamic mechanical properties of semi-interpenetrating networks based on poly(styrene-co-maleic anhydride)
Semi-interpenetrating networks based on linear anionic polystyrene (PS) and poly(styrene-co-maleic anhydride) P(ScoMA) of low MA content are prepared by crosslinking the P(ScoMA) with 4,4′-diphenylmethanediamine (DPMDA). It is demonstrated by dynamic mechanical analysis and by DSC that immiscible semi-IPN's are obtained for MA contents greater 5 wt.-%. In miscible semi-IPN's the relaxation of free PS chains is observed as a second maximum in the loss tangent at higher temperatures. The position of this maximum is shifted to higher temperatures for a polystyrene of molecular weight 500000 compared to a polystyrene of molecular weight 150000. The experimental temperature shift is in good agre…