Abstract
The miscibility of poly(styrene- co-vinylphenol) containing 5% vinylphenol monomer units (MPS-5) with syndiotactic poly(methyl methacrylate) (PMMA-s) and with isotactic poly(methyl methacrylate) (PMMA-i) was studied with 13C solid state n.m.r. complemented with cloud point and differential scanning calorimetry measurements. Above room temperature, the results indicate that the PMMA-s blends have a wider composition range over which the system exists in a single phase. In the time scale of spin-lattice proton relaxation, or a dimensional scale of about 25 nm, PMMA-s is miscible with MPS-5 in all compositions studied, namely 30, 50, and 70 wt% of MPS-5; PMMA-i is miscible only at one composition, namely 70% styrene copolymer. Both PMMA-s and PMMA-i blends indicate the existence of heterogeneities in the time scale of rotating frame spin-lattice relaxation ( T H 1 ϱ ), or a dimensional scale of about 2 nm, for all compositions studied except for 70 30 MPS-5 PMMA-i , which shows a single T H 1 ϱ . The glass transition temperature data of these blends are consistent with the n.m.r. observation. The cloud point diagram is also in agreement with n.m.r. results.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have