Isothermal growth of low molecular weight polyethylene single crystals from solution. 3. Kinetic studies

1985 ◽  
Vol 18 (4) ◽  
pp. 760-771 ◽  
Author(s):  
W. M. Leung ◽  
R. St. John Manley ◽  
A. R. Panaras
Keyword(s):  
Molecular Weight ◽  
Single Crystals ◽  
Kinetic Studies ◽  
Low Molecular Weight ◽  
Isothermal Growth

Lateral habits of single crystals of metallocene-catalyzed low molecular weight short chain branched polyethylene from the melt

Polymer ◽  
2000 ◽  
Vol 41 (24) ◽  
pp. 8573-8577 ◽  
Author(s):  
Jieping Liu ◽  
Fengchao Xie ◽  
Binyang Du ◽  
Fajun Zhang ◽  
Qiang Fu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Single Crystals ◽  
Short Chain ◽  
Low Molecular Weight ◽  
Branched Polyethylene

scholarly journals Pentamethylcyclopentadienyl Molybdenum(V) Complexes Derived from Iodoanilines: Synthesis, Structure, and ROP of ε-Caprolactone

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1554
Author(s):  
Tian Xing ◽  
Mark R. J. Elsegood ◽  
Sophie H. Dale ◽  
Carl Redshaw
Keyword(s):  
Molecular Weight ◽  
Comparative Studies ◽  
Ring Opening ◽  
Kinetic Studies ◽  
Ring Opening Polymerization ◽  
Molecular Structures ◽  
Low Molecular Weight ◽  
End Groups ◽  
Amine Complex ◽  
Reaction Stoichiometry

The reaction of [Mo(η-C5Me5)Cl4] with the ortho-, meta-, or para-iodo-functionalized anilines 2-IC6H4NH2, 3-IC6H4NH2, 4-IC6H4NH2 yields imido or amine products of the type [Mo(η-C5Me5)Cl2(IC6H4N)] (2-I, 1, 3-I, 3, 4-I, 5) or [Mo(η-C5Me5)Cl4(IC6H4NH2)] (3-I, 2, 4-I, 4), respectively, depending on the reaction stoichiometry/conditions; we were unable to isolate an amine complex of the 2-I derivative. The reaction of [Mo(η-C5Me5)Cl4] with one equivalent of 2-I,4-FC6H3NH2 in the presence of Et3N afforded [Mo(η-C5Me5)Cl2(2-I,4-FC6H3N)]·MeCN (6·MeCN), which, upon exposure to air, afforded the Mo(VI) imido complex [Mo(η-C5Me5)Cl3(2-I,4-FC6H3N)] (7). For comparative studies, the structure of the aniline (C6H5NH2)-derived complex [Mo(η-C5Me5)Cl2(2-C6H3N)] (8) has also been prepared. The molecular structures of 1–8 have been determined and reveal packing in the form of zig-zag chains or ladders. The complexes catalyze, in the presence of benzyl alcohol under N2, the ring-opening polymerization (ROP) of ε-caprolactone affording relatively low molecular weight products. The MALDI-ToF spectra indicate that a number of polymer series bearing a variety of end groups are formed. Conducting the ROPs as melts or under air results in the isolation of higher molecular weight products, again bearing a variety of end groups. Kinetic studies reveal the aniline-derived imido complex 8 performs best, whilst a meta-iodo substituent and a Mo(V) centre are also found to be beneficial. The structures of the side products 2-IC6H4NH3Cl and 3-IC6H4NH3Cl are also reported.

scholarly journals Effect of polyethylene glycol on crystal growth and photocatalytic activity of anatase TiO2 single crystals

RSC Advances ◽  
2020 ◽  
Vol 10 (21) ◽  
pp. 12511-12518 ◽  
Author(s):  
Yeshuo Dong ◽  
Fanjun Meng
Keyword(s):  
Molecular Weight ◽  
Photocatalytic Activity ◽  
Crystal Growth ◽  
Polyethylene Glycol ◽  
Single Crystals ◽  
Anatase Tio2 ◽  
Low Molecular Weight

Anatase TiO2 crystals with different structures were synthesized. Experiments on the effect of polyethylene glycol show that the low molecular weight PEG (PEG400) can accelerate crystal differentiation and relieve the agglomeration of crystals.

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