Thermal Analysis of Butadiene Styrene Block Copolymers

1969 ◽  
Vol 42 (3) ◽  
pp. 918-923 ◽  
Author(s):  
J. N. Anderson ◽  
F. C. Weissert ◽  
C. J. Hunter
Keyword(s):  
Thermal Analysis ◽  
Osmium Tetroxide ◽  
Polymer Degradation ◽  
Glass Temperature ◽  
Index Method ◽  
K Value ◽  
Styrene Copolymers ◽  
Compositional Distribution ◽  
Composition Graph ◽  
Butadiene Styrene

Abstract The Gordon—Taylor—Wood relationship between composition and glass temperature has been used as the basis of a DTA method for block styrene analysis in butadiene styrene copolymers having the same microstructure and a similar compositional distribution. The determined K value of the Gordon—Taylor—Wood equation for these polymers prepared with a butyllithium catalyst is in fair agreement with values previously determined for emulsion butadiene styrene copolymers. The total styrene content of the copolymer was determined using the refractive index method, and the composition of the “non-block” segment of the copolymer was obtained from DTA measurement using a Tg as a function of composition graph The amount of block styrene can then be obtained by difference. Evidence is presented supporting the validity of the method, and the results are compared with those obtained by a chemical method which involved polymer degradation by a hydroperoxide in the presence of osmium tetroxide. The thermal analysis requires approximately one-half hour. All measurements are made on the dry polymer eliminating the necessity of redissolving the polymer as required by most other methods of analysis.

scholarly journals 3D Printing of PDMS-Like Polymer Nanocomposites with Enhanced Thermal Conductivity: Boron Nitride Based Photocuring System

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 373 ◽  
Author(s):  
Lorenzo Pezzana ◽  
Giacomo Riccucci ◽  
Silvia Spriano ◽  
Daniele Battegazzore ◽  
Marco Sangermano ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Analysis ◽  
Boron Nitride ◽  
Thermal Analyses ◽  
Tensile Tests ◽  
Morphological Characterization ◽  
Digital Light Processing ◽  
Form Complex ◽  
K Value ◽  
Enhanced Thermal Conductivity

This study demonstrates the possibility of forming 3D structures with enhanced thermal conductivity (k) by vat printing a silicone–acrylate based nanocomposite. Polydimethylsiloxane (PDSM) represent a common silicone-based polymer used in several applications from electronics to microfluidics. Unfortunately, the k value of the polymer is low, so a composite is required to be formed in order to increase its thermal conductivity. Several types of fillers are available to reach this result. In this study, boron nitride (BN) nanoparticles were used to increase the thermal conductivity of a PDMS-like photocurable matrix. A digital light processing (DLP) system was employed to form complex structures. The viscosity of the formulation was firstly investigated; photorheology and attenuate total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) analyses were done to check the reactivity of the system that resulted as suitable for DLP printing. Mechanical and thermal analyses were performed on printed samples through dynamic mechanical thermal analysis (DMTA) and tensile tests, revealing a positive effect of the BN nanoparticles. Morphological characterization was performed by scanning electron microscopy (SEM). Finally, thermal analysis demonstrated that the thermal conductivity of the material was improved, maintaining the possibility of producing 3D printable formulations.

Effect of Temperature on Ozone Cracking of Rubbers

1966 ◽  
Vol 39 (3) ◽  
pp. 643-650
Author(s):  
A. N. Gent ◽  
J. E. McGrath
Keyword(s):  
Polymer Chains ◽  
Effect Of Temperature ◽  
Ozone Molecule ◽  
Segmental Mobility ◽  
Network Chain ◽  
Styrene Copolymers ◽  
Rates Of Growth ◽  
Rate Controlling Step ◽  
Limiting Value ◽  
Butadiene Styrene

Abstract The rates of growth of single ozone cracks have been measured for vulcanizates of a series of butadiene—styrene copolymers, over a temperature range from − 5° C to 95° C. The rates appear to be determined by two mechanisms. At low temperatures, near the glass transition temperature, they are quantitatively related to the segmental mobility of the polymer. The principal rate-controlling step in this case is concluded to be movement of the polymer chains after scission to yield new surface. At high temperatures the rate approaches a limiting value of 10−3 cm/sec/mg of ozone/1. This is about 1/1000 of the maximum possible value when instantaneous reaction of one incident ozone molecule causes scission of one network chain.

Monomer Sequence Distribution in Butadiene Styrene Copolymers

1970 ◽  
Vol 43 (5) ◽  
pp. 1138-1153 ◽  
Author(s):  
V. D. Mochel ◽  
B. L. Johnson
Keyword(s):  
Aromatic Proton ◽  
Analog Computer ◽  
Curve Analysis ◽  
Nmr Spectrum ◽  
Sequence Distribution ◽  
Monomer Sequence ◽  
Styrene Copolymers ◽  
Overlapped Peaks ◽  
Sequence Distributions ◽  
Butadiene Styrene

Abstract A method is described for determining styrene sequence distribution in butadiene-styrene copolymers. An analog computer is used to resolve overlapped peaks in the styrene aromatic proton NMR spectrum. In n-BuLi copolymers a quite quantitative distinction can be made between “short” sequences, containing two and three styrene units, and “long” sequences, containing more than three units. With this method it is possible to determine experimentally the styrene-centered triad distributions and approximate styrene sequence distributions of butadiene—styrene copolymers. Agreement between calculated and NMR-curve analysis results is good, especially for n-butyllithium-catalyzed butadiene—styrene copolymers.

Influence of the degree of microblock structures on properties of butadiene-styrene copolymers

1986 ◽  
Vol 28 (7) ◽  
pp. 1645-1652 ◽  
Author(s):  
M.M. Mogilevich ◽  
Yu.Ye. Shapiro ◽  
V.B. Manerov ◽  
G.V. Korolev ◽  
T.A. Yermilova
Keyword(s):  
Styrene Copolymers ◽  
Butadiene Styrene

Flow Patterns in Elastomers and Their Carbon Black Compounds during Extrusion through Dies

1985 ◽  
Vol 58 (4) ◽  
pp. 815-829 ◽  
Author(s):  
Chin-Yuan Ma ◽  
James L. White ◽  
Frederick C. Weissert ◽  
Avraam I. Isayev ◽  
Nobuyuki Nakajima ◽  
...  
Keyword(s):  
Carbon Black ◽  
Natural Rubber ◽  
Flow Patterns ◽  
Entrance Region ◽  
Evidence Based ◽  
Streamline Flow ◽  
Basic Study ◽  
Entrance Angle ◽  
Styrene Copolymers ◽  
Butadiene Styrene

Abstract A basic study of flow patterns in elastomers in the entrance region of a die has been carried out for various gum elastomers including emulsion and solution butadiene—styrene copolymers, polybutadiene, and natural rubber. All exhibit streamline flow into the entrance with the exception of a cold mastication degraded natural rubber which gave evidence of vortices in corners. A study of a die with a sharp diverging region showed dead spaces for all the elastomers. Carbon black compounds all exhibited converging streamline flow in a 180° entrance angle die and stagnant regions in the sharply diverging die. Evidence based on marker motions has been presented for slip in elastomer compounds in the entrance region.

COMPATIBILITY AND PROPERTIES OF BLENDS OF POLYCARBONATE AND ACRYLONITRILE-BUTADIENE-STYRENE COPOLYMERS

1998 ◽  
Author(s):  
M.LI. MASPOCH ◽  
O. O. SANTANA ◽  
P. PAGÉS ◽  
J. PÉREZ-FOLCH ◽  
J. MAS ◽  
...  
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Styrene Copolymers ◽  
Butadiene Styrene
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