Full Characterization of a Multiblock Copolymer Based on Poly(2,6-dimethyl-1,4-phenylene oxide) and Poly(bisphenol-A carbonate)

Abstract

Full characterization, that is the true molar mass distribution and block sequence, of a multiblock copolymer based on poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and poly(bisphenol A carbonate) (PC) segments (PPO-b-PC), synthesized by polycondensation reaction of both diol-terminated PPO and PC samples with the bischloroformate of bisphenol A, is reported. The initial diol terminated PPO sample contains a few tetramethyl bisphenol A units in the backbone. The molar mass distribution of the starting PPO and PC homopolymers and the multiblock structure of the final PPO-b-PC copolymers were studied by light scattering and viscometry online with a SEC system, MALDI-TOF mass spectrometry, and NMR. In a previous study, we have demonstrated that homogeneous PPO-b-PC block copolymers having only one single T g were obtained if low molar mass PPO and PC starting blocks were used. More important findings of this recent study are the following. MALDI-TOF analysis showed that the synthesized PPO-b-PC copolymers were composed of multiblock PPO-b-PC chains and also of some nonreacted PC oligomers terminated with methyl carbonate groups. Exhaustive and selective aminolysis of carbonate groups of the PC blocks has been also performed in order to determine the number of blocks and the average length of PPO blocks in the copolymers.

One Pot, One Feeding Step, Two-Stage Polymerization Synthesis and Characterization of (PTT-b-PTMO-b-PTT)n Multiblock Copolymers

“…For block copolymer systems, normally K and α parameters are different for different blocks with a given solvent, so the equation can hardly be applied to estimate the molecular weights of block copolymers due to the difficulty in finding the universal parameters . This is more complicated in multiblock copolymer systems, as the structures of the multiblock copolymers with different molecular weights are not the same, and they may have lower dynamic viscosity compared to the similar homopolymer component . How can this be applied in the multiblock copolymers is interesting, and we are currently investigating that.…”

“…43 This is more complicated in multiblock copolymer systems, as the structures of the multiblock copolymers with different molecular weights are not the same, and they may have lower dynamic viscosity compared to the similar homopolymer component. 44 How can this be applied in the multiblock copolymers is interesting, and we are currently investigating that.…”

Triblock copolymers composed of soft and semi-crystalline segments—synthesis and characterization of poly[(n-butyl acrylate)-block-(ε-caprolactone)-block-(L-lactide)]

“…It has been reported that compatibility of polymers is dependent on the molecular weight and at low molecular weights even incompatible polymers could be compatible and as a result show a single glass transition temperature. 24 Previously, we have observed that the melting transitions were completely supressed when the block copolymers were intentionally admixed with homo-and copolymers in order to verify the purity of block copolymers. 21 Table 3 summarizes the thermal characteristics of di-and triblock copolymers.…”

Application of High-Resolution MALDI-TOFMS with a Spiral Ion Trajectory for the Structural Characterization of Free Radical Polymerized Methacrylate Ester Copolymers

“…1) Copolymer characterization has also been attempted using MALDI-TOFMS. [2][3][4][5][6][7][8] However, the structural characterization of copolymers remains a challenging task, since the random nature of comonomer distribution generates very complicated mass spectra. During free radical polymerization of copolymers, a variety of end-group combinations are formed, resulting in extremely intricate mass spectra.…”