scholarly journals Structural and Thermo-Mechanical Properties of Poly(ε-caprolactone) Modified by Various Peroxide Initiators

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1101 ◽  
Author(s):  
Przybysz ◽  
Hejna ◽  
Haponiuk ◽  
Formela
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Dicumyl Peroxide ◽  
Organic Peroxides ◽  
Reactive Processing ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Gel Fraction

The modification of poly(ε-caprolactone) (PCL) was successfully conducted during reactive processing in the presence of dicumyl peroxide (DCP) or di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB). The peroxide initiators were applied in the various amounts of 0.5 or 1.0 pbw (part by weight) into the PCL matrix. The effects of the initiator type and its concentration on the structure and mechanical and thermal properties of PCL were investigated. To achieve a detailed and proper explication of this phenomenon, the decomposition and melting temperatures of DCP and BIB initiators were measured by differential scanning calorimetry. The conjecture of the branching or cross-linking of PCL structure via used peroxides was studied by gel fraction content measurement. Modification in the presence of BIB in PCL was found to effectively increase gel fraction. The result showed that the cross-linking of PCL started at a low content of BIB, while PCL modified by high DCP content was only partially cross-linked or branched. PCL branching and cross-linking were found to have a significant impact on the mechanical properties of PCL. However, the effect of used initiators on poly(ε-caprolactone) properties strongly depended on their structure and content. The obtained results indicated that, for the modification towards cross-linking/branching of PCL structure by using organic peroxides, the best mechanical properties were achieved for PCL modified by 0.5 pbw BIB or 1.0 pbw DCP, while the PCL modified by 1.0 pbw BIB possessed poor mechanical properties, as it was related to over cross-linking.

scholarly journals Chemistry of collagen cross-links: glucose-mediated covalent cross-linking of type-IV collagen in lens capsules

1993 ◽  
Vol 296 (2) ◽  
pp. 489-496 ◽  
Author(s):  
A J Bailey ◽  
T J Sims ◽  
N C Avery ◽  
C A Miles
Keyword(s):  
Type Iv Collagen ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Maximum Strain ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Type Iv ◽  
Collagen Molecules ◽  
Cross Links

The incubation of lens capsules with glucose in vitro resulted in changes in the mechanical and thermal properties of type-IV collagen consistent with increased cross-linking. Differential scanning calorimetry (d.s.c.) of fresh lens capsules showed two major peaks at melting temperatures Tm 1 and Tm 2 at approx. 54 degrees C and 90 degrees C, which can be attributed to the denaturation of the triple helix and 7S domains respectively. Glycosylation of lens capsules in vitro for 24 weeks caused an increase in Tm 1 from 54 degrees C to 61 degrees C, while non-glycosylated, control incubated capsules increased to a Tm 1 of 57 degrees C. The higher temperature required to denature the type-IV collagen after incubation in vitro suggested increased intermolecular cross-linking. Glycosylated lens capsules were more brittle than fresh samples, breaking at a maximum strain of 36.8 +/- 1.8% compared with 75.6 +/- 6.3% for the fresh samples. The stress at maximum strain (or ‘strength’) was dramatically reduced from 12.0 to 4.7 N.mm.mg-1 after glycosylation in vitro. The increased constraints within the system leading to loss of strength and increased brittleness suggested not only the presence of more cross-links but a difference in the location of these cross-links compared with the natural lysyl-aldehyde-derived cross-links. The chemical nature of the fluorescent glucose-derived cross-link following glycosylation was determined as pentosidine, at a concentration of 1 pentosidine molecule per 600 collagen molecules after 24 weeks incubation. Pentosidine was also determined in the lens capsules obtained from uncontrolled diabetics at a level of about 1 per 100 collagen molecules. The concentration of these pentosidine cross-links is far too small to account for the observed changes in the thermal and mechanical properties following incubation in vitro, clearly indicating that another as yet undefined, but apparently more important cross-linking mechanism mediated by glucose is taking place.

Influence of Bagasse Carboxymethyl Cellulose Addition on the Thermal and Mechanical Properties of PLA Composites

2013 ◽  
Vol 747 ◽  
pp. 157-161
Author(s):  
S. Kamthai ◽  
Rathanawan Magaraphan
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Tensile Strength ◽  
Carboxymethyl Cellulose ◽  
Room Temperature ◽  
Environmental Concern ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Melting Temperatures ◽  
Bagasse Waste

According to the availability of bagasse waste and increasing environmental concern, this research is focused on the preparation of polylactic acid (PLA)/bagasse carboxymethyl cellulose (CMCB) composite in order to improve the thermal and mechanical properties of PLA/CMCB film. PLA were mixed with CMCB at different ratios (1, 2, 4 and 8%, w/w of PLA), by kneading in two roll mills and then hot pressing into film. The results revealed that the addition of CMCB had significant effects on PLA composites properties. Differential scanning calorimetry (DSC) measurement indicated that the presence of CMCB accelerated the reduction of glass transition, and melting temperatures. Moreover the CMCB could improve the storage modulus of PLA composites at high temperature because its cold crystallization was developed. At room temperature, the tensile strength and elongation of PLA composite (but not modulus) were not significantly different with an increase of CMCB contents.

scholarly journals The Use of Copper Oxides as Cross-Linking Substances for Chloroprene Rubber and Study of the Vulcanizates Properties. Part I

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5535
Author(s):  
Piotr Kobędza ◽  
Aleksandra Smejda-Krzewicka ◽  
Krzysztof Strzelec
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Structural Changes ◽  
Copper Oxides ◽  
Cross Linking ◽  
Cross Link ◽  
Scanning Calorimetry ◽  
Ir Studies ◽  
Chloroprene Rubber

The purpose of this work was to verify the ability to cross-link the chloroprene rubber (CR) by using copper oxides: copper(I) oxide or copper(II) oxide. The use of copper oxides arises from the need to limit the application of ZnO as a cross-linking agent of CR. The obtained results indicate that CR compositions cross-linked with copper oxides are characterized by good mechanical properties and a high cross-linking degree. The results show that the type and the amount of copper oxides influence the cross-linking of the CR and the properties of the vulcanizates. For compositions containing copper(II) oxide, the properties are linearly dependent on the amount of CuO. Such a relationship is difficult to notice in the case of the use of copper(I) oxide—when analyzing individual parameters, the best results are obtained for different samples. Infrared spectroscopy (IR) studies confirmed the possibility of cross-linking of chloroprene rubber with copper oxides. This is evidenced by the characteristic changes in the intensity of the bands. Structural changes in the material during heating were determined by the thermal analysis—differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Regardless of the type and amount of copper oxide, all compositions exhibit similar characteristics, and there are no significant changes in the glass transition temperature of the material.

Synthesis of long chain semiaromatic polyamides based on decanediamine

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Wenzhi Wang ◽  
Ruixue Li ◽  
Baoyu Liu ◽  
Yonghua Zhang
Keyword(s):  
Mechanical Properties ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Tensile Strength ◽  
Physical And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Melting Temperatures ◽  
Ft Ir ◽  
Long Chain

AbstractLong chain semiaromatic polyamides were synthesized by the reactions of decanediamine with various aromatic diacids, and characterized by Fourier transform infrared spectrum (FT-IR) and nuclear magnetic resonance (1H-NMR). The thermal behaviours were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The solubility, dynamic mechanical, physical and mechanical properties of the polyamides were also investigated. The resultant polyamides have intrinsic viscosity ranging from 1.7 dL/g to 2.1 dL/g. Their melting temperatures range from 305 °C to 343 °C, and the glass transition temperatures fall in the range of 125 °C - 130 °C. The tensile strength of the polyamides is above 100 MPa.

Research on compatibility and surface of high impact bio-based polyamide

2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
High Impact ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.

Effects of Steam Heat and Dry Heat Sterilization on Thermal and Mechanical Properties of Nylon and Policarbonate in Fabrication with Fused Filament

2021 ◽  
Vol 891 ◽  
pp. 150-163
Author(s):  
Jorge Mauricio Fuentes ◽  
Omar Flor Unda ◽  
Santiago Ferrandiz ◽  
Franyelit Suarez
Keyword(s):  
Mechanical Properties ◽  
Thermomechanical Analysis ◽  
Mechanical Tests ◽  
Effect Of Temperature ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Thermal Tests ◽  
Dry Heat ◽  
Izod Impact ◽  
Steam Heat

In this article presents evidence about performance of mechanical properties of polycarbonate and nylon materials, which are used in the additive manufacturing by deposition of molten material and that have been subjected to sterilization processes by moist heat at 121°C and dry heat at 140°C. This study provides useful information to consider the use of these materials in sanitary and sterile settings. Mechanical tests of tensile, flex, hardness, Izod impact, thermal tests in Differential Scanning Calorimetry DSC, Thermomechanical analysis TMA and Scanning Electron Microscopy SEM were performed. It is concluded that the mechanical and thermal properties have not been altered through the effect of temperature in sterilization processes.

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.

Physico Chemical Characterization of Nanofibrous Poly(Ε-Caprolactone) Electrospun Templates for Cell Adhesion

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2689-2694
Author(s):  
Karla A. Gaspar-Ovalle ◽  
Juan V. Cauich-Rodriguez ◽  
Armando Encinas
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Cell Adhesion ◽  
Tensile Modulus ◽  
Chemical Characterization ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Physico Chemical ◽  
Static Water

ABSTRACTNanofibrous mats of poly ε-caprolactone (PCL) were fabricated by electrospinning. The nanofiber structures were investigated and characterized by scanning electron microscope, differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis, static water-contact-angle analysis and mechanical properties. The results showed that the nanofibrous PCL is an ideal biopolymer for cell adhesion, owing to its biocompatibility, biodegradability, structural stability and mechanical properties. Differential scanning calorimetry results showed that the fibrous structure of PCL does not alter its crystallinity. Studies of the mechanical properties, wettability and degradability showed that the structure of the electrospun PCL improved the tensile modulus, tensile strength, wettability and biodegradability of the nanotemplates. To evaluate the nanofibrous structure of PCL on cell adhesion, osteoblasts cells were seeded on these templates. The results showed that both adhesion and proliferation of the cells is viable on these electrospun PCL membranes. Thus electrospinning is a relatively inexpensive and scalable manufacturing technique for submicron to nanometer diameter fibers, which can be of interest in the commodity industry.

Corrosion Property Analysis of Coating Formulated Using Acrylic Polyol and Silicone Resin Hybrid Systems

2013 ◽  
Vol 746 ◽  
pp. 363-368
Author(s):  
S.K.M. Jamaria ◽  
K. Rameshb ◽  
B. Vengadaesvaranc ◽  
S. Rameshd ◽  
S.R. Raue ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Corrosion Property ◽  
Cross Linking ◽  
Silicone Resin ◽  
Scanning Calorimetry ◽  
Maximum Value ◽  
Infra Red ◽  
Protection Property

Coating systems consist of acrylic polyol resin and silicone intermediate resins were tested for their corrosion resistance properties. The corrosion protection property of the coating was evaluated by using Electrochemical Impedance Spectroscopy (EIS) which showed that system with 70 % of acrylic has the highest corrosion resistance. The maximum value of corrosion resistance obtained was found to be 1.40 x 109Ω on the 30thday for the 70 % of acrylic sample. The glass transition temperature (Tg) obtained using the Differential Scanning Calorimetry (DSC) were in the range of 23 °C to 65 °C. It showed that all samples are suitable for decorative paints, general industrial coatings and floor care coatings. The functional groups and also the cross-linking between the organic resins were analyzed using Fourier Transform Infra-Red Spectroscopy.

A comparative study on the effect of higher acrylate on cross-linkable PMMA used as environment friendly latexes

2020 ◽  
Vol 32 (2) ◽  
pp. 135-141
Author(s):  
Sweta Shukla
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Butyl Methacrylate ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
Environment Friendly ◽  
Glycol Diacrylate ◽  
Poly Propylene ◽  
Kinetics Of ◽  
Scanning Electron

The kinetics of emulsion polymerization of monomers methyl methacrylate (MMA)/ n-butyl methacrylate (BMA) was studied to investigate the effect of cross-linkable monomer poly(propylene glycol diacrylate) (PPGDA). The results showed that by the incorporation of PPGDA rate constant of reaction decreased. Fourier transform infrared spectroscopy and scanning electron microscope were used to characterize the synthesized polymers. The thermal analysis of samples was done by differential scanning calorimetry, and the results were compared by the previous studies with MMA/ n-butyl acrylate (BA) and MMA/2-ethylhexyl acrylate (EHA). The glass transition temperature ( T g) values show that the latexes prepared using BA and EHA as comonomer was suitable for binder purpose, but in the present study the T g is not suitable in case of BMA as higher acrylate comonomer. That may be due to more cross-linking in MMA-BMA-PPGDA. The results conclude that the BA and EHA can be used as the binder, but the use of BMA is limited for the binder in coating applications.

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