Free-radical polymerization of tetraethyl (2,3-dimethylenebutane-1,4-diyl)bis(phosphonate), a 1,3-butadiene derivative containing two diethyl phosphonate functions in a molecule, was carried out under various conditions. When polymerization was performed in benzene at 60°C for 21 h with using 1 mol% of 2,2′-azobisisobutyronitrile as an initiator, sticky polymer was obtained in 70% yield without forming gel. Number average molecular weight of the polymer thus obtained was estimated to be 69,000 by SEC based on polystyrene calibration using N,N-dimethylformamide as an eluent. The rate of polymerization was found to be proportional to 0.5 and 1.5 power of the initiator and the monomer concentration, respectively. The overall activation energy of polymerization was determined to be 91.4 kJ/mol. The microstructure of the polymer was exclusively 1,4- but both E and Z configurations were contained. Glass transition temperature of the polymer was -18°C. Monomer reactivity ratio of the monomer with styrene as comonomer was determined to be r_st=0.15, r₂=6.1.

View full abstract

To create novel antistatic polymer materials, we prepared ion-conductive elastomer blends consisting of commercial NBR (with acrylonitrile (AN) content of 18 and 33% (NBR18, NBR33)) with nano-ordered domains of polyether electrolyte. In this study, we prepared blend samples using two different methods, solvent-casting and mechanical mixing methods. The oligo-[(ethylene oxide)-co-(propylene oxide)] methacrylate (M(EO/PO)) was mixed and polymerized in the NBR matrix including KSCN. Obtained elastomer blends showed relatively good conductivity more than 10^-7 S cm^-1 and the difference in the conductivity of the cast samples under dry and wet conditions was especially very small, and the ratio of conductivity under dry and wet condition of NBR18 blends was lower than 0.06. The TEM images indicated that the order of sea-island phase separation in blend samples may effect on the ion-conductive behavior under different humidity conditions. Moreover, the NBR33 with 30 wt% of PM(EO/PO) sample showed the conductivity of the order of 10^-6 S cm^-1, and we considered that the large interface between NBR33 and polyether electrolyte domains may effect the increase in the conductivity.

View full abstract

Anionic polymerization of two 1,3-butadiene derivatives containing trimethylsilyl-protected primary amino groups, 2-(N,N-bistrimethylsilylaminomethyl)-1,3-butadiene (SA1Bd) and 2-(4-(N,N-bistrimethylsilylamino)butyl)-1,3-butadiene (SA4Bd) were carried out under various conditions. When anionic polymerization of SA1Bd was attempted in cyclohexane at room temperature with using sec-BuLi as an initiator, no polymerization took place at all. Polystyrene having dienyl end group was obtained if anionic living polystyrene was used as an initiator, presumably due to the isomerization of carbanion accompanied with elimination of bistrimethylsilylamide anion. Such a side reaction was not observed in the anionic polymerization of SA4Bd. Polymer of predictable molecular weight with narrow molecular weight distributions was obtained in the polymerization in toluene. Microstructure of the resulting polymer was 86% 1,4-structure though its geometry was not clear. Block copolymer with styrene was also obtained.

View full abstract