Effect of polyurethane‐based macromonomers in the dispersion polymerization of styrene

Abstract

Two different polyurethane-based macromonomers, a polyurethane macromonomer with methacrylamide (PUM-M) and a polyurethane macromonomer with acrylamide (PUM-A), were synthesized from poly(ethylene glycol)s (PEGs) of various molecular weights and two different amides, methacrylamide and acrylamide, and they were used for the dispersion polymerization of styrene. The structures of the macromonomers and polystyrene (PS) particles were verified with 13 C-NMR and Fourier transform infrared. The weight-average molecular weights of the PS particles increased with the macromonomer concentration but decreased with the PEG molecular weight. The average diameter of the PS particles increased with the PEG molecular weights but decreased with the macromonomer concentration. The thermal stability of PUM-A-PS was enhanced, and its grafting ratio with 30 wt % PUM-A was much higher than that of PUM-M-PS. Thus, this study suggested that the polyurethane-based macromonomers act not only as reactive stabilizers but also as grafting agents in the dispersion polymerization. In addition, the acrylamide end group provided better thermal stability than methacrylamide.

Synthesis of PMMA Microparticles with a Narrow Size Distribution by Photoinitiated RAFT Dispersion Polymerization with a Macromonomer as the Stabilizer

“…Their reported particle size distributions ranged from PDI = 1.03, which is relatively narrow to 1.34, which is much broader. Choe’s group , reported the synthesis and characterization of a series of bifunctional vinyl urethane macromonomers with different molecular weights, and applied them to the dispersion polymerization of styrene in ethanol. They obtained polystyrene particles with diameters ranging from 1.4 to 4.4 μm and with PDI values ranging from 1.03 to 2.79.…”

Copolumers obtained by grafting of vinyl monomers on starch - influence of amines on synthesis and degradation processes in environment

“…Dobijeni poliuretan sa terminalnim vinilnim grupama moţe se koristiti kao makromonomer. Reakcija dobijanja kopolimera se odigravala u uljanom kupatilu, a reakciona temperatura je fiksirana i iznosila je 70 0 C. Pored prethodno navedenog makromonomera u reakciji kalemljenja sa PS mogu se koristiti i makromonomeri poliuretana sa terminalnim vinilnim grupama nastalim u reakciji metilakrilamida i akrilamida sa poliuretanom nastalim iz poli(etilen-glikola) (PEG) i heksametilen-diizocijanata [45]. Veći stepeni kalemljenja dobijeni su kada se kao makromonomer koristio kopolimer poliuretana sa akrilamidom u količini od 30 masenih procenata.…”