scholarly journals Modeling of Molecular Weight Distribution in Ring-Opening Polymerization of l,l-Lactide

2014 ◽  
Vol 53 (18) ◽  
pp. 7333-7342 ◽  
Author(s):  
Yingchuan Yu ◽  
Eric J. Fischer ◽  
Giuseppe Storti ◽  
Massimo Morbidelli
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Ring Opening ◽  
Ring Opening Polymerization

A unique cooperative catalytic system carrying metallic iron and 2-hydroxyethyl 2-bromoisobutyrate for the controlled/living ring-opening polymerization of ε-caprolactone

RSC Advances ◽  
2016 ◽  
Vol 6 (14) ◽  
pp. 11400-11406 ◽  
Author(s):  
Xiu-Juan Shang ◽  
Wen-Hua Zhang ◽  
Jian-Ping Lang
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Molecular Weight Distribution ◽  
Catalytic System ◽  
Weight Distribution ◽  
Metallic Iron ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Narrow Molecular Weight Distribution

Iron and 2-hydroxyethyl 2-bromoisobutyrate cooperatively initiates the ε-caprolactone polymerization, yielding polymers with high molecular weight and narrow molecular weight distribution.

Organocatalytic Ring-Opening Polymerization Strategies for Synthesis of Poly(phosphothioesters) with a Pendent Phenyl Group

Synlett ◽  
2020 ◽  
Vol 31 (12) ◽  
pp. 1167-1171 ◽  
Author(s):  
Guangqiang Xu ◽  
Xin-Qi Hao ◽  
Qinggang Wang ◽  
Huating Yan ◽  
Rulin Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Weight Distribution ◽  
Ring Opening ◽  
Diblock Copolymers ◽  
Phenyl Group ◽  
Ring Opening Polymerization ◽  
Polymerization Process ◽  
Narrow Molecular Weight Distribution ◽  
Living Nature

A novel type of phosphothioester substrate, 2-phenyl-1,3,2-dioxaphospholane 2-sulfide (PTP), has been synthesized and subjected to ring-opening polymerization. DBU/thiourea served as an efficient cooperative organocatalyst for the synthesis of poly(PTP), delivering the polymer with a well-defined structure, a relatively narrow molecular-weight distribution (1.14–1.20), and high molecular weight (up to 45.2 kg/mol). The ring-opening polymerization process showed a controlled/living nature. In addition, diblock copolymers of PTP with rac-lactide with well-defined structures were also synthesized.

scholarly journals Ring-Opening Polymerisation ofrac-Lactide Using a Calix[4]arene-Based Titanium (IV) Complex

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Marco Frediani ◽  
David Sémeril ◽  
Dominique Matt ◽  
Luca Rosi ◽  
Piero Frediani ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Treatment ◽  
Microwave Irradiation ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Ring Opening ◽  
The Other ◽  
Maldi Tof ◽  
Other Hand ◽  
First Time

cone-25,27-Dipropyloxy-26,28-dioxo-calix[4]arene titanium (IV) dichloride(1)has been assessed in the ring-opening polymerisation ofrac-lactide (L,D-LA). The polymers formed (PLDA) turned out to display an isotactic stereoblock microstructure (determined by NMR) despite the fact that the catalyst hasC2vsymmetry. Two techniques were applied for initiating the polymerisation reaction, microwave irradiation, and conventional thermal treatment. The polymers obtained were all characterised by NMR, IR, HPLC-SEC, DSC, and MALDI-TOF analysis. The use of microwave irradiation, applied for the first time to calixarene-based catalysts in the presence of therac-lactide monomer, increased the polymerisation rate compared with that obtained by the other method. On the other hand, standard thermal treatment enabled a slightly better control than microwave irradiation over the molecular weight and molecular weight distribution of the polylactides formed.

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