Influence of a resorcin[4]arene core structure on the spatial directionality of multi-arm poly(ε-caprolactone)s

RSC Advances ◽  
2014 ◽  
Vol 4 (32) ◽  
pp. 16864-16870 ◽  
Author(s):  
Ruizhi Wu ◽  
Talal F. Al-Azemi ◽  
Kirpal S. Bisht
Keyword(s):  
Physical Properties ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Core Structure ◽  
Polymer Chains

The spatial directionality of polymer chains in multi-arm polymers can be used to manipulate their thermal and physical properties. Synthesis of directional poly(ε-caprolactone), based on a rigid and flexible resorcin[4]arene initiator core, was accomplished via ring-opening polymerization catalyzed by Sn(Oct)2 in bulk at 120 °C.

scholarly journals End-Group Evaluation of HEMA Initiated Poly(ε-caprolactone) Macromonomers via Enzymatic Ring-Opening Polymerization

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
N. Ugur Kaya ◽  
Y. Avcibasi Guvenilir
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Enzyme Concentration ◽  
Polymer Chains ◽  
Side Reactions ◽  
Initiator Concentration ◽  
Lower Temperature

Poly(ε-caprolactone) (PCL) macromonomers comprising acrylate end-functionality were synthesized via enzymatic ring-opening polymerization (eROP) by utilizing commercially availableCandida antarcticaLipase B (CALB), Novozyme-435. 2-Hydroxyethyl methacrylate (HEMA) was purposed to be the nucleophilic initiator in eROP. The side reactions generated due to the cleavage of ester bonds in HEMA and the growing polymer chains were investigated through altering polymerization period, initiator concentration, temperature, and enzyme concentration.1H NMR evaluations showed that minimum quantities of side reactions were in lower temperatures, initiator concentration, enzyme concentration, and lower monomer conversions. Gel permeation chromatography (GPC) results revealed that lower polydispersity along with number-average molecular weight of end-functionalized PCL macromonomers was obtained depending on higher initiator/monomer ratios, lower temperature (60°C), enzyme concentration (100 mg), and/or polymerization time (2 h). Furthermore, 0.1 HEMA/ε-caprolactone (CL) ratio had higher molecular weight than 0.5 HEMA/CL ratio, while keeping a close value of methacrylate transfer, total methacrylate end-groups, and lower polyester transfer.

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 Photochromic Polyamide 6 Based on Spiropyran Synthesized via Hydrolyzed Ring-Opening Polymerization

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2496
Author(s):  
Shiyou Tian ◽  
Jicong Zhang ◽  
Qiong Zhou ◽  
Limei Shi ◽  
Wenwen Wang ◽  
...  
Keyword(s):  
Fatigue Resistance ◽  
Ring Opening ◽  
Uv Light ◽  
Polyamide 6 ◽  
Ring Opening Polymerization ◽  
Polymer Chains ◽  
Photochromic Property ◽  
Crystallinity Degree ◽  
Property Analysis

We report photochromic polyamide 6 (PA6) which was synthesized by hydrolyzed ring-opening polymerization of ε-caprolactam with spiropyran (SP) embedded in the polymer chains. It indicated that crystallinity degree of the resulting copolymers was decreased since only PA6 segments can crystallize with increasing content of SP modifier. Meanwhile, toughness of photochromic PA6 was decreased. The photochromic property analysis indicated that the sample with more flexibility and more content of SP was more sensitive to UV light at the beginning of irradiation than other samples and its color after being irradiated for 1 min tended to reddish. Investigation revealed that the UV-vis absorbance of SP-PA6-3 had negligible decay after 10 cycles, which indicated SP-modified PA6 possessed excellent photoresponse reversibility and fatigue resistance.

Polymers from Cycloolefins

1971 ◽  
Vol 44 (5) ◽  
pp. 1341-1349 ◽  
Author(s):  
Kenneth W. Scott ◽  
Nissim Calderon ◽  
E. A. Ofstead ◽  
W. A. Judy ◽  
J. P. Ward
Keyword(s):  
Molecular Weight ◽  
Double Bond ◽  
Physical Properties ◽  
High Molecular Weight ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Great Range ◽  
Linear Chains ◽  
Ring Opening Reaction ◽  
Special Case

Abstract Ring-opening polymerization of cycloolefins has led to a variety of new plastics and elastomers with a great range in physical properties. Ring-opening polymerization of cycloolefins, employing organoaluminum-tungsten salt catalysts, is a special case of olefin metathesis, a new reaction. The ring-opening reaction occurs at the double bond and allows making either large ring macro-cyclics or high molecular weight linear chains. Under certain conditions ringchain equilibrium can be established in these systems.

A dinuclear zinc complex containing a diamond-core geometry: [Zn2(μ2-GueO)2(GueO)2(py)2]·0.5(toluene) (GueOH is guethol)

2013 ◽  
Vol 69 (4) ◽  
pp. 372-375 ◽  
Author(s):  
Rafał Petrus ◽  
Piotr Sobota
Keyword(s):  
Catalytic Activity ◽  
Ring Opening ◽  
Zinc Complex ◽  
Solvent Molecule ◽  
Ring Opening Polymerization ◽  
Core Structure ◽  
Complex Molecules ◽  
Coordination Modes ◽  
Efficient Generation ◽  
Distorted Octahedral

The title zinc alkoxide, bis(μ-2-ethoxyphenolato)-κ3O1,O2:O1;κ3O1:O1,O2-bis[(2-ethoxyphenolato-κ2O1,O2)(pyridine-κN)zinc(II)] toluene hemisolvate, [Zn2(C8H9O2)4(C5H5N)2]·0.5C7H8, crystallizes with two independent complex molecules located on inversion centres and one independent toluene solvent molecule disordered about an inversion centre. The ZnIIatoms are six-coordinated in distorted octahedral geometries with O5N donor sets. The ZnIIions and bridging alkoxide groups are arranged in a diamond Zn2O2core structure. The guetholate (2-ethoxyphenolate) ligands adopt two different coordination modes,viz.peripheral chelating and μ2-bridging. Preliminary investigations of the catalytic activity of the compound in the ring-opening polymerization of L-lactide demonstrate rapid and efficient generation of polylactide.

scholarly journals Insight into the Alcohol-Free Ring-Opening Polymerization of TMC Catalyzed by TBD

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1589
Author(s):  
Fabrice Azemar ◽  
Olinda Gimello ◽  
Julien Pinaud ◽  
Jean-Jacques Robin ◽  
Sophie Monge
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Polymer Chains ◽  
Size Exclusion ◽  
Trimethylene Carbonate ◽  
Free Ring ◽  
Molecular Weights ◽  
Cyclic Polymer ◽  
Exclusion Chromatography

We report herein a study on the alcohol-free, ring-opening polymerization of trimethylene carbonate (TMC) in THF, catalyzed by 1,5,7-triazabicyclo [4.4.0] ec-5-ene (TBD) with ratios nTBD/nTMC ranging between 1/20 and 1/400. In all cases, the reaction proceeds very rapidly, even faster than in the presence of alcohol initiators, and provides PTMC with molecular weights up to Mn = 34,000 g mol−1. Characterization of the obtained PTMC samples by MALDI-TOF mass spectrometry, triple detection size exclusion chromatography and 1H NMR spectroscopy reveals the presence of both linear and cyclic polymer chains.

A Recommender System for Inverse Design of Polycarbonates and Polyesters

2020 ◽  
Author(s):  
Nathaniel Park ◽  
Dmitry Yu. Zubarev ◽  
James L. Hedrick ◽  
Vivien Kiyek ◽  
Christiaan Corbet ◽  
...  
Keyword(s):  
Ring Opening ◽  
High Performance ◽  
Recommendation System ◽  
Polymeric Materials ◽  
Monomer Conversion ◽  
Design Strategy ◽  
Ring Opening Polymerization ◽  
Inverse Design ◽  
False Negatives ◽  
Accelerate Development

The convergence of artificial intelligence and machine learning with material science holds significant promise to rapidly accelerate development timelines of new high-performance polymeric materials. Within this context, we report an inverse design strategy for polycarbonate and polyester discovery based on a recommendation system that proposes polymerization experiments that are likely to produce materials with targeted properties. Following recommendations of the system driven by the historical ring-opening polymerization results, we carried out experiments targeting specific ranges of monomer conversion and dispersity of the polymers obtained from cyclic lactones and carbonates. The results of the experiments were in close agreement with the recommendation targets with few false negatives or positives obtained for each class.<br>

Bisurea and Bisthiourea H-Bonding Organocatalysts for Ring-Opening Polymerization: Cues for the Catalyst Design

2019 ◽  
Vol 52 (23) ◽  
pp. 9232-9237 ◽  
Author(s):  
Rukshika S. Hewawasam ◽  
U. L. D. Inush Kalana ◽  
Nayanthara U. Dharmaratne ◽  
Thomas J. Wright ◽  
Timothy J. Bannin ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Catalyst Design
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