Effect of Substituents on Aggregation Behaviors of Stilbazole and Stilbazolium Derivatives

Abstract

Stilbamle and stilbazdium derivatives with dialkylaniline as electron pushing substituents and pyridine or pyridinium substituents BS electron drawing substituents were synthesized and their aggregation behaviors were shdied by UV-Visible, flu+ rescellce and surface photovoltage spectroscopies. Experimental results indicate that the formation of aggregates can be mediated by the electron drawing ability of the substituents introduced for those compounds all bearing strong electron pushing substibent. When the electron drawing substituent is pyridine group, the molecules tend to aggregate in head-btail mannm, whereas the substituent is pyridinium group, the molecules tend to aggregate in face-*face manner. The effect of electron pushing and drawing ability of the substituents on the aggregation behavior is further analyzed in terms of fmn-8 tier orbital interactions. (400 MHz, CqCl): 0.88 ( t , J = 5 . 1 Hz, 6H, 2~ CH3), 1.25-1.82 (m, 52H, 26 x CH2), 1.50-1.70 ( m , 12H, 2xNCH2(CH,),), 3.29 ( t , J = 5 . 0 ArH),6.75(d, J = 1 6 . 2 H z , lH, = C H ) , 7 . 2 2 ( d , J = 16.2 H z , lH, = CH), 7.31 ( d , J = 5 . 9 Hz, 2H, ArH), 7.40 ( d , J = 9 . 2 Hz, 2H, PyH), 8.49 C, 80.83; H, 11.40; N, 3.63. Found: C, 81.14; J = 5 . 0 Hz, 6H, 2~ CH3), 1.20-1.80 (m, 60H, . 3 0~ CHZ), 2.84 ( I , J = 4.5 H z , 4H, 2 x NCHZCH,), 2.91-3.15 ( m , 2H, N' CHZCH,), 3.32 (t, J = 5.4 Hz, 4H, 2 x NCHZ), 4.67-4.89 ( m , 2H, N' CH2), 6.62 ( d , J = 6.6 Hz, 2H, ArH), 6.73 ( d , J = 12.0 Hz, lH, = CH), 7.46 ( d , J = 6 . 3 Hz, 2H, ArH), 7.50 ( d , J = 12.6 Hz, lH, =CHI, 7.64 ( d , J = 3 . 6 Hz,

Coupled Single‐Particle and Population Balance Modeling for Particle Size Distribution of Poly(propylene) Produced in Loop Reactors

“…In the loop reactor, small solid catalyst particles (e.g., 20–100 µm) react with monomers to form polymer particles in a size range of 100–5 000 µm in a liquid phase and the polymer particles are produced as a solid suspension in the liquid stream 1. In addition, the polymerization rate, the cost of post‐treatment after polymeric process and the polymer properties are influenced by the polymer particle size distribution (PSD) 2–7. Therefore, the polymer PSD modeling thus analyzing how operational variables may affect PSD via simulation may be useful for the understanding of the propylene polymerization in loop reactors, especially the intraparticle mass and heat transfer limitations, the feed catalyst particle size and the polymerization temperature, etc.…”