scholarly journals Preparation and mechanical properties of PCL-based polyurethanes as potential biomaterials for short-term applications

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Marcin Sobczak ◽  
Cezary Dębek ◽  
Piotr Goś
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Ring Opening ◽  
Soft Segment ◽  
Ring Opening Polymerization ◽  
Mechanical And Thermal Properties ◽  
Short Term ◽  
Metal Free ◽  
Molecular Weights

AbstractA series of polyurethanes (PURs) were prepared by metal-free method, containing polycaprolactone (PCL) as the soft segment with molecular weights of 1600, 2400 and 2600. PCL was obtained by the ring-opening polymerization of ε- caprolactone in the presence L-alanine and L-phenyloalanine. The structure of synthesized oligoesters and PURs were spectroscopically confirmed. The molecular weights, mechanical and thermal properties of the obtained materials were reported.

scholarly journals One-Pot Synthesis of Star Copolymers by the Combination of Metal-Free ATRP and ROP Processes

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1577 ◽  
Author(s):  
Gorkem Yilmaz
Keyword(s):  
Visible Light Irradiation ◽  
Ring Opening ◽  
Reaction Medium ◽  
Ring Opening Polymerization ◽  
One Pot ◽  
Metal Free ◽  
Molecular Weights ◽  
Star Copolymers ◽  
Living Polymerizations ◽  
Chromatographic Evidence

A completely metal-free strategy is demonstrated for the preparation of star copolymers by combining atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) for the syntheses of block copolymers. These two different metal-free controlled/living polymerizations are simultaneously realized in one reaction medium in an orthogonal manner. For this purpose, a specific core with functional groups capable of initiating both polymerization types is synthesized. Next, vinyl and lactone monomers are simultaneously polymerized under visible light irradiation using specific catalysts. Spectral and chromatographic evidence demonstrates the success of the strategy as star copolymers are synthesized with controlled molecular weights and narrow distributions.

Synthesis of Polyethers from Epoxides via Binary Organocatalyst System

2021 ◽  
Author(s):  
Ge-Ge Gu ◽  
Li-Yang Wang ◽  
Rong Zhang ◽  
Tian-Jun Yue ◽  
Bai-Hao Ren ◽  
...  
Keyword(s):  
Ring Opening ◽  
High Efficiency ◽  
Main Chain ◽  
Ring Opening Polymerization ◽  
Metal Free ◽  
Molecular Weights ◽  
Chain Sequence ◽  
Catalyst Systems

The development of “metal-free” catalyst systems with high efficiency for the ring-opening polymerization (ROP) of epoxides, providing polyethers with controlled molecular weights and dispersity as well as desired main-chain sequence...

scholarly journals Development of PE/PCL Bilayer Films Modified with Casein and Aluminum Oxide

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3090
Author(s):  
Anita Ptiček Siročić ◽  
Ana Rešček ◽  
Zvonimir Katančić ◽  
Zlata Hrnjak-Murgić
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Water Vapor ◽  
Aluminum Oxide ◽  
Water Vapor Permeability ◽  
Vapor Permeability ◽  
Mechanical And Thermal Properties ◽  
Oxide Compound ◽  
Bilayer Films ◽  
Oxide Particles

The studied samples were prepared from polyethylene (PE) polymer which was coated with modified polycaprolactone (PCL) film in order to obtain bilayer films. Thin PCL film was modified with casein/aluminum oxide compound to enhance vapor permeability as well as mechanical and thermal properties of PE/PCL films. Casein/aluminum oxide modifiers were used in order to achieve some functional properties of polymer film that can be used in various applications, e.g., reduction of water vapor permeability (WVTR) and good mechanical and thermal properties. Significant improvement was observed in mechanical properties, especially in tensile strength as well as in water vapor values. Samples prepared with aluminum oxide particles indicated significantly lower values up to 60%, and samples that were prepared with casein and 5% Al2O3 showed the lowest WVTR value.

Synthesis of metal-free poly(1,4-dioxan-2-one) by enzyme-catalyzed ring-opening polymerization

2000 ◽  
Vol 38 (9) ◽  
pp. 1560-1567 ◽  
Author(s):  
Haruo Nishida ◽  
Mitsuhiro Yamashita ◽  
Masumi Nagashima ◽  
Takeshi Endo ◽  
Yutaka Tokiwa
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Metal Free

The influence of adding long basalt fiber on the mechanical and thermal properties of composites based on poly(oxymethylene)

2018 ◽  
Vol 33 (4) ◽  
pp. 435-450 ◽  
Author(s):  
Patrycja Bazan ◽  
Stanisław Kuciel ◽  
Mariola Sądej
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Average Length ◽  
Flexural Modulus ◽  
Basalt Fiber ◽  
Charpy Impact ◽  
Mechanical And Thermal Properties ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Atr Spectroscopy

The work has evaluated the possibility of the potential reinforcing of poly(oxymethylene) (POM) by basalt fibers (BFs) and influence of BFs addition on thermal properties. Two types of composites were produced by injection molding. There were 20 and 40 wt% long BFs content with an average length of 1 mm. The samples were made without using a compatibilizer. In the experimental part, the basic mechanical properties (tensile strength, modulus of elasticity, strain at break, flexural modulus, flexural strength, and deflection at 3.5% strain) of composites based on POM were determined. Tensile properties were also evaluated at three temperatures −20°C, 20°C, and 80°C. The density and Charpy impact of the produced composites were also examined. The influence of water absorption on mechanical properties was investigated. Thermal properties were conducted by the differential scanning calorimetry, thermal gravimetric analysis, and fourier transform infrared (FTIR)-attenuation total reflection (ATR) spectroscopy analysis. In order to make reference to the effects of reinforcement and determine the structure characteristics, scanning electron microscopy images were taken. The addition of 20 and 40 wt% by weight of fibers increases the strength and the stiffness of such composites by more than 30–70% in the range scale of temperature. Manufactured composites show higher thermal and dimensional stability in relation to neat POM.

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