scholarly journals ANALISIS SIFAT TERMAL DAN UJI KELARUTAN DARI KARET ALAM SIKLIS DAN KARET ALAM CAIR SIKLIS

2018 ◽  
Vol 16 (1) ◽  
pp. 36
Author(s):  
Leni Widiarti ◽  
Basuki Wirjosentono ◽  
Eddyanto Eddyanto
Keyword(s):  
Thermal Analysis ◽  
Transition Temperature ◽  
Natural Rubber ◽  
Oxidative Degradation ◽  
Melting Transition ◽  
Scanning Calorimetry ◽  
Solubility Test ◽  
Polarity Index ◽  
Liquid Natural Rubber ◽  
Crystal Transition

Abstract. The research has done analysis of thermal properties and solubility test of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR). Cyclic Liquid Natural Rubber (CLNR) is a cyclical natural rubber which has decreased molecular weight. Synthesis of Cyclic Liquid Natural Rubber (CLNR) do by oxidative degradation after cyclic.  Oxidative degradation after cyclic using Cyclic Natural Rubber (CNR) and phenylhydrazine reagent with flow rate 2 LMin-1 of oxygen atmosphere during 24 hours. Thermal analysis of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) by Differential Scanning Calorimetry (DSC),the glass transition temperature (Tg) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 102,82  o C and 103,67 o C, the crystal transition temperature (Tc) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 362,45 o C and 330,29 o C and the melting transition temperature ( Tm) of Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) are 509,24 o C and 440,00 o C. Solubility test by dilute Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR) in some solvent with different properties and polarity index. Solubility test shows the results Cyclic Natural Rubber (CNR) and Cyclic Liquid Natural Rubber (CLNR)  has polarity index around 2,4 – 4,4 and 2,4 and 4,4.               Keywords: CLNR, CNR, oxidative degradation

scholarly journals Thermal analysis: basic concept of differential scanning calorimetry and thermogravimetry for beginners

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nurul Fatahah Asyqin Zainal ◽  
Jean Marc Saiter ◽  
Suhaila Idayu Abdul Halim ◽  
Romain Lucas ◽  
Chin Han Chan
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Commercial Application ◽  
Scanning Calorimetry ◽  
Teaching Activities ◽  
Sample Decomposition ◽  
Calibration Baseline

AbstractWe present an overview for the basic fundamental of thermal analysis, which is applicable for educational purposes, especially for lecturers at the universities, who may refer to the articles as the references to “teach” or to “lecture” to final year project students or young researchers who are working on their postgraduate projects. Description of basic instrumentation [i.e. differential scanning calorimetry (DSC) and thermogravimetry (TGA)] covers from what we should know about the instrument, calibration, baseline and samples’ signal. We also provide the step-by-step guides for the estimation of the glass transition temperature after DSC as well as examples and exercises are included, which are applicable for teaching activities. Glass transition temperature is an important property for commercial application of a polymeric material, e.g. packaging, automotive, etc. TGA is also highlighted where the analysis gives important thermal degradation information of a material to avoid sample decomposition during the DSC measurement. The step-by-step guides of the estimation of the activation energy after TGA based on Hoffman’s Arrhenius-like relationship are also provided.

scholarly journals Functionalization of Liquid Natural Rubber via Oxidative Degradation of Natural Rubber

Polymers ◽  
2014 ◽  
Vol 6 (12) ◽  
pp. 2928-2941 ◽  
Author(s):  
Suhawati Ibrahim ◽  
Rusli Daik ◽  
Ibrahim Abdullah
Keyword(s):  
Natural Rubber ◽  
Oxidative Degradation ◽  
Liquid Natural Rubber

scholarly journals Cryoprotective effect of polydextrose on chicken surimi

2011 ◽  
Vol 29 (No. 3) ◽  
pp. 226-231 ◽  
Author(s):  
D. Kovačević ◽  
K. Mastanjević ◽  
J. Kordić
Keyword(s):  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Transition Temperature ◽  
Freezing Point ◽  
Thermal Transition ◽  
Scanning Calorimetry ◽  
Native Proteins ◽  
Mass Fractions ◽  
Initial Freezing ◽  
Kappa Carrageenan

Two thermal analysis techniques &ndash; Differential scanning calorimetry (DSC) and Differential thermal analysis (DTA), &ndash; were used to study the cryoprotective effects of polydextrose on chicken surimi. The samples of chicken surimi were mixed with: (a) different mass fractions of polydextrose (w = 2&ndash;10%), (b) &kappa;-carrageenan (w = 0.5%) and different mass fractions of polydextrose (w = 2&ndash;10%), and (c) NaCl (w = 2%) and different mass fractions of polydextrose (w = 2&ndash;10%). Chicken surimi was produced following a modified procedure of Dawson et al. (1988) on a broiler (Sasso, 12 weeks, and 1.73 kg live wt.), that was quickly frozen and stored for 3 months at &ndash;25&deg;C. Initial freezing point (<sub><sup>T</sup>i</sub>), thermal transition temperature (T<sub>p</sub>), and denaturation enthalpy (&Delta;H) were evaluated. The greatest effects of the cryoscopic depression of the initial freezing point T<sub>i</sub> were exhibited by the samples of chicken surimi with added 2% NaCl and 10% polydextrose. Differential scanning calorimetry (DSC) revealed a shift in the thermal transition temperature of myosin and actin to a higher temperature as the mass fraction of polydextrose increased. Since the denaturation enthalpy is directly related to the amount of native proteins, higher values of &Delta;H indicate higher cryoprotective effects of polydextrose. &nbsp;

scholarly journals Glass Transition Temperature and Microhardness of Compatible and Incompatible Elastomer/Plastomer Blends

1970 ◽  
Vol 33 (1) ◽  
pp. 15-24 ◽  
Author(s):  
MF Mina ◽  
GH Michler ◽  
FJ Balta Calleja
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Natural Rubber ◽  
Methyl Methacrylate ◽  
Core Shell ◽  
Scanning Calorimetry ◽  
Rubber Toughened ◽  
Shell Particles

Glass transition temperature (Tg) of core-shell particles-toughened poly(methyl- methacrylate) (CSPTPMMA) and natural rubber-toughened PMMA (NRTPMMA), which are basically the PMMA/elastomer blends with different concentrations of elastomer heterogeneously distributed in the samples, was investigated by means of differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and microindentation technique (MT). Microhardness (H) of the samples was measured using MT. Core-shell particles (CSP) with a rubbery shell and natural rubber (NR) were used as reinforcing materials for the production of compatible and incompatible blends, respectively. Results reveal a good correlation of the glass transition temperature (Tg) obtained from DSC and DMA, and that deduced from MT.  The H-value of each sample is compared with its Tg-value. Increase of Tg with the increase of H, which is a general behavior of polymers, is not maintained in the both blends investigated. Contrary to expectation, H is shown to decrease with increasing glass transition temperature in case of CSP-toughened compatible blends while it decreases with the decrease of Tg-value only in case of NR-modified incompatible blends for lower NR concentration (<1 wt%) and does not depend on Tg for rubber content higher than 1 wt%.  Keywords: Glass transition temperature, microhardness, rubber-toughened poly(methyl -methacrylate), core-shell particle, differential scanning calorimetry DOI: 10.3329/jbas.v33i1.2946 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 1, 15-24, 2009

scholarly journals Preparation and characterization of liquid natural rubber through oxidative degradation with phenyl hydrazine and benzoyl peroxide-oxygen

2021 ◽  
Vol 912 (1) ◽  
pp. 012098
Author(s):  
Tamrin ◽  
S Leny ◽  
Eddiyanto
Keyword(s):  
Natural Rubber ◽  
Benzoyl Peroxide ◽  
Oxidative Degradation ◽  
Chain Scission ◽  
Phenyl Hydrazine ◽  
Vacuum Oven ◽  
Liquid Natural Rubber ◽  
Chain Scission Reaction ◽  
Rubber Product

Abstract The aim of this research was to synthesize liquid natural rubber (LNR) from Natural rubber (SIR-20) by chain scission method in the presence of oxygen gas and difference of peroxides, phenyl hydrazine and benzoyl peroxide. The chain scission reaction was conducted in solution of xylene in close system. SIR-20 was diluted xylene before flushing with oxygen and the addition of the peroxide. The degradation oxidation by the oxygen and the peroxides was processed at 60°C for 24 hours. The degradative oxidation product was re-precipitated by adding the excess of methanol and filtrated before dried in vacuum oven 60°C for 24 hours. The dried product was characterized by Fourier Transform Infra Red (FTIR). It was found that the liquid natural rubber product successfully degraded by chain scission process as shown the change of the peak area intensity of infrared absorption. It was showed the peaks area intensity of O-H and carbonyl group of liquid natural rubber spectra increased.

Fabrication of Novel Polyhydroxybutyrate-co-Hydroxyvalerate (PHBV) Mixed with Natural Rubber Latex

2015 ◽  
Vol 659 ◽  
pp. 404-408 ◽  
Author(s):  
Karndarthip Kuntanoo ◽  
Sarunya Promkotra ◽  
Pakawadee Kaewkannetra
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Testing Machine ◽  
Natural Rubber Latex ◽  
Melting Behavior ◽  
Melting Transition ◽  
Rubber Latex ◽  
Scanning Calorimetry ◽  
Wide Range ◽  
Mixed Films

Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is mixed with natural rubber latex to make better mechanical properties of PHBV. The various ratios between PHBV and natural rubber latex are examined to improve their mechanical properties. The PHBV are solid, easily broken, while natural rubber is excessive elastic materials. Concentrations of the employed PHBV solution are 1, 2, and 3 (%w/v). The mixtures of this solution to natural rubber latex are fabricated the biofilms in three different ratios, 4:6, 5:5, and 6:4, respectively. The films are characterized by electron microscope, universal testing machine, and differential scanning calorimetry (DSC). The electron micrographs of the mixed films and unmixed PHBV yield the lowest void distributions in 3%w/v PHBV. For mechanical properties, the averaged elastic moduli of 1, 2, and 3 (%w/v PHBV) mixed films are 773, 955 and 1,008 kPa, respectively. Their tensile strengths increase with increasing the PHBV concentrations. A similar trend is also found in elastic modulus. The crystallization and melting behavior of pure PHBV and the mixed films are examined by DSC. Melting transition temperatures of pure PHBV exhibit two melting peaks at 154°C and 173°C. In addition, the melting peaks of the mixed films remain in the range of 152-156°C and 168-171°C, respectively. According to their morphology, void distributions reduce twice, compared to the unmixed PHBV. Mechanical properties and thermal analysis indicate that the mixed PHBV can be improved their properties with more resilient and wide range temperature than usual.

Determining the Glass Transition Temperature of an Epoxy Siloxane Composite by Thermal Analysis Methods

2018 ◽  
Vol 45 (6) ◽  
pp. 269-274
Author(s):  
V.S. Osipchik ◽  
Yu.V. Olikhova ◽  
L.Kh. Nguen ◽  
G.A. Lushcheikin ◽  
V.M. Aristov
Keyword(s):  
Thermal Analysis ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Three Dimensional ◽  
Thermomechanical Analysis ◽  
Mechanical Analysis ◽  
Strength Properties ◽  
Dimensional Structure ◽  
Scanning Calorimetry

Thermomechanical analysis, dynamic mechanical analysis, differential scanning calorimetry, and dielectric thermal analysis were used to determine the glass transition temperature of hot-curing epoxy siloxane composites. The effect of polymethylphenylsiloxane resin on the parameters of the three-dimensional structure and on the deformation and strength properties of epoxy novolac resin during curing by 4,4′-diaminodiphenylmethane was established.

Sign in / Sign up

Export Citation Format

Share Document