Anionic Ring-Opening Polymerization Simulations for Hyperbranched Polyglycerols with Defined Molecular Weights

2013 ◽  
Vol 46 (21) ◽  
pp. 8458-8466 ◽  
Author(s):  
Florian Paulus ◽  
Maximilian E. R. Weiss ◽  
Dirk Steinhilber ◽  
Anatoly N. Nikitin ◽  
Christof Schütte ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Molecular Weights ◽  
Anionic Ring

Synthesis and characterization of novel β-cyclodextrin cored poly(α-caprolactone)s by anionic ring opening polymerization

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Yingzhi Guo ◽  
Changjiang Yu ◽  
Zhongwei Gu
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
Ring Opening ◽  
Monomer Conversion ◽  
Ring Opening Polymerization ◽  
Molar Ratio ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Anionic Ring ◽  
Feed Molar Ratio

Abstract By anionic ring opening polymerization initiated by cyclodextrin oxyanions generated from NaH and β-cyclodextrin(β-CD), novel biodegradable β- CD cored star-shaped poly(ε-caprolactone)s (s-PCLs) were synthesized and then characterized by means of FTIR, GPC, 1H-NMR. The effects of different feed molar ratios of NaH and β-CD on arm number and on the molecular weight of s-PCLs, and the relationship between the polymerization time and monomer conversion were investigated. Moreover, the physical properties of linear PCL (l-PCL) and s- PCLs with similar molecular weights but different arm number were studied and compared by DSC, SEM and intrinsic viscosity measurement, respectively. It was found that the feed molar ratio of NaH and β-CD is an important factor which influences both the molecular weight and arm number. The melting points and intrinsic viscosities of s-PCLs with similar molecular weights were lower than that of l-PCL, and were found to decrease with increasing arm number. Both SEM and AFM showed that the surface morphology of s-PCL films was different from that of l-PCL. These results indicated that s-PCL with different arms and physical properties could be synthesized using just a β-CD core by adjusting the feed molar ratio of NaH and β-CD

scholarly journals Post-Polymerization Heat Effect in the Production of Polyamide 6 by Bulk Quasiliving Anionic Ring-Opening Polymerization of ε-Caprolactam with Industrial Components: A Green Processing Technique

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 856
Author(s):  
Zsófia Osváth ◽  
Anita Szőke ◽  
Szabolcs Pásztor ◽  
Györgyi Szarka ◽  
László Balázs Závoczki ◽  
...  
Keyword(s):  
Ring Opening ◽  
In Situ Polymerization ◽  
Reaction Times ◽  
Polyamide 6 ◽  
Ring Opening Polymerization ◽  
Processing Technique ◽  
Molecular Weights ◽  
Reaction Injection Molding ◽  
Anionic Ring ◽  
High Yields

Bulk, solventless anionic ring-opening polymerization (AROP) of ε-caprolactam (CPL) with high yields, without side products and with short reaction times, initiated by caprolactamate-carbamoylcaprolactam initiating systems belong to green polymerization processes, leading to poly(ε-caprolactam) (Polyamide 6, PA6, Nylon 6). However, the effect of post-polymerization heat (i.e., slow, technically feasible cooling) on the fundamental characteristics of the resulting polymers such as yield and molecular weight distributions (MWDs) have not been revealed thus far. Significant post-polymerization effect was found by us in terms of both monomer conversions and MWDs by carrying out CPL polymerization with industrial components under conditions mimicking thermoplastic reaction transfer molding (T-RTM). Remarkably, higher monomer conversions and molecular weights (MWs) were obtained for Polyamide 6 samples prepared without quenching than that for the quenched polymers at the same reaction times. Independent of quenching or non-quenching, Mn of the resulting polymers as a function of conversion fell in the theoretical line of quasiliving AROP of CPL. At high monomer conversions, significant increase of the MW and broadening of the MWDs occurred, indicating pronounced chain–chain coupling. These findings have fundamental importance for designing processing conditions for in situ polymerization processes of ε-caprolactam by various techniques such as T-RTM, reaction injection molding (RIM), and other processing methods of Polyamide 6.

Follow-up of the course of the anionic ring-opening polymerization of lactams onto an isocyanate-bearing polymer backbone in the melt

2006 ◽  
Vol 102 (5) ◽  
pp. 4394-4403 ◽  
Author(s):  
Guo-Hua Hu ◽  
Huxi Li ◽  
Lian-Fang Feng
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Polymer Backbone ◽  
Anionic Ring

Nonequilibrium Anionic Ring-opening Polymerization of Tetraphenyltetramethylcyclotetrasiloxane (D4Me,Ph) Initiated by Sodium Isopropoxide

2014 ◽  
Vol 189 (10) ◽  
pp. 1514-1528 ◽  
Author(s):  
Xiyin Gao ◽  
Qian Wang ◽  
Hongjie Sun ◽  
Yongxia Tan ◽  
Zhijie Zhang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Anionic Ring

Anionic ring-opening polymerization of propylene oxide in the presence of phosphonium catalysts

2002 ◽  
Vol 40 (7) ◽  
pp. 864-873 ◽  
Author(s):  
Ornulf Rexin ◽  
Rolf Mülhaupt
Keyword(s):  
Propylene Oxide ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Anionic Ring
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