Rates of Crystallization of cis-1,4-Polybutadiene in Elastomer Blends

1967 ◽  
Vol 40 (2) ◽  
pp. 341-349 ◽  
Author(s):  
M. C. Morris
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Glass Transition ◽  
Thermal Properties ◽  
Electron Microscope ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Rate Data ◽  
Thermal And Mechanical Properties ◽  
Crystallization Properties

Abstract Blends of polybutadiene with SBR show different crystallization behavior than blends with polyisoprene. One might suppose that the similarities in SBR and polybutadiene are sufficient to allow more intimate mixing than can be obtained by using entirely different polymers such as the polyisoprene polybutadiene pair. Possibly, bulk viscosities are important here, but no matter what the cause, crystallization properties have shown differences in the way the polybutadiene was situated. Also, large changes in the glass transition occurred for those materials which showed sizeable retardation in crystallization rate. An interpretation of the crystallization rate data based on particle size was given in this discussion because a precedent exists for this effect. However, molecular compatibility has not been ruled out. Further investigation of thermal properties should help clarify this point. It will be interesting to learn to what extent particle size alone affects the thermal behavior of blends. Perhaps more work along these lines coupled with improved optical and electron microscope techniques will provide some answers to our questions on how phase structure affects thermal and mechanical properties.

Fabrication and characterization of carbon nanofibers coated expandable thermoplastic microspheres-based polymer composites

2022 ◽  
Vol 05 ◽  
Author(s):  
Wanda Jones ◽  
Bedanga Sapkota ◽  
Brian Simpson ◽  
Tarig A. Hassan ◽  
Shaik Jeelani ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Thermal Properties ◽  
Carbon Nanofibers ◽  
Spherical Particles ◽  
Sonochemical Method ◽  
Thermal And Mechanical Properties ◽  
Polymer Shell ◽  
Composite Foam ◽  
Composite Foams

Background: Thermoplastic expandable microspheres (TEMs) are spherical particles that consist of polymer shell encapsulating a low boiling point liquid hydrocarbon that acts as the blowing agent. When TEMs are heated at 80-190 C, the polymer shell softens and the hydrocarbon gasifies, causing the microspheres expand leading to increase in volume and decrease in density. TEMs are used in food packaging, elastomeric cool roof coatings, shoe soles, fiber and paper board, and various applications in the automotive industry. It is noted that TEMs are known by its brand name ‘Expancel’ which is also used to refer TEMs in this paper. Objective: The objective of this work was to develop and characterize forms prepared from TEMs with/without carbon nanofibers (CNFs) coatings to study the effect of CNFs on structural, thermal, and mechanical properties. Method: Sonochemical method was used to coat TEMs with various weight percentage (1, 2, and 3 %) of CNF. Neat foam (without CNF) and composite foams (TEMs coated with various wt.% of CNF) were prepared by compression molding the TEMs and TEMs-CNF composites powders. Thermal and mechanical properties of the neat and composite foams were investigated. Result: The mechanical properties of the composite foam were notably improved, which is exhibited by a 54% increase in flexural modulus and a 6% decrease in failure strain with the TEMs-(2 wt.% CNF) composite foam as compared to the neat foam. Improvement in thermal properties of composite foam was demonstrated by a 38% increase in thermal stability at 800 ºC with the TEMs-(1 wt.% CNF) composite foam as compared to the neat foam. However, no change in glass transition of TEMs was observed with the CNF coating. SEM-based analysis revealed that CNFs were well dispersed throughout the volume of the TEMs matrix forming a strong interface. Conclusions: Straightforward sonochemical method successfully triggered efficient coating of TEMs with CNFs resulting to strong adhesion interface. The mechanical properties of composite foams increased up to 2% of CNFs coating and then decreased with the higher coating presumably due to interwoven bundles and aggregation of CNFs, which might have acted as critical flaws to initiate and propagate cracking. Thermal properties of foams increased with the CNFs coating while no change in glass transition temperature was observed due to coating.

scholarly journals Effect of 1,2,4,5-Benzenetetracarboxylic Acid on Unsaturated Poly(butylene adipate-co-butylene itaconate) Copolyesters: Synthesis, Non-Isothermal Crystallization Kinetics, Thermal and Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1160 ◽  
Author(s):  
Chin-Wen Chen ◽  
Te-Sheng Hsu ◽  
Kuan-Wei Huang ◽  
Syang-Peng Rwei
Keyword(s):  
Mechanical Properties ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Cross Linking ◽  
Thermal And Mechanical Properties ◽  
Isothermal Crystallization Kinetics ◽  
Melt Polymerization ◽  
Thermal Mechanical Properties

Unsaturated poly (butylene adipate-co-butylene itaconate) (PBABI) copolyesters were synthesized through melt polymerization composed of 1,4-butanediol (BDO), adipic acid (AA), itaconic acid (IA) and 1,2,4,5-benzenetetracarboxylic acid (BTCA) as a cross-linking modifier. The melting point, crystallization and glass transition temperature of the PBABI copolyesters were detected around 29.8–49 °C, 7.2–29 °C and −51.1 and −58.1 °C, respectively. Young’s modulus can be modified via partial cross-linking by BTCA in the presence of IA, ranging between 32.19–168.45 MPa. Non-isothermal crystallization kinetics were carried out to explore the crystallization behavior, revealing the highest crystallization rate was placed in the BA/BI = 90/10 at a given molecular weight. Furthermore, the thermal, mechanical properties, and crystallization rate of PBABI copolyesters can be tuned through the adjustment of BTCA and IA concentrations.

scholarly journals A study on the crystallization behavior and mechanical properties of poly(ethylene terephthalate) induced by chemical degradation nucleation

RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37139-37147 ◽  
Author(s):  
Diran Wang ◽  
Faliang Luo ◽  
Zhiyuan Shen ◽  
Xuejian Wu ◽  
Yaping Qi
Keyword(s):  
Mechanical Properties ◽  
Crystallization Behavior ◽  
Ethylene Terephthalate ◽  
Crystallization Rate ◽  
Chemical Degradation ◽  
Carboxylate Anion ◽  
Nucleate Agent ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Pet Crystallization

In order to overcome low crystallization rate of PET, HPN-68L was selected to replace the special nucleate agent of PET to improve PET crystallization for its carboxylate anion structure which usually showed high induced nucleation ability for PET.

Mechanical and thermal properties of PP/compatibilized PP/acid treated SWNTs nanocomposites: Effect of different acid treatment times

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Morteza Ghorbanzadeh Ahangari ◽  
Abdolhosein Fereidoon ◽  
Seyfolah Saedodin
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Acid Treatment ◽  
Treatment Process ◽  
Tensile Tests ◽  
Acid Mixture ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Maleated Polypropylene ◽  
Carboxylic Groups

AbstractIn the present work, the effect of different acid treatment times of singlewalled carbon nanotubes (SWNTs) on the mechanical and thermal properties of polypropylene (PP)/maleated polypropylene (PP-g-MA) nanocomposites was investigated. The acid treatment process was based on a mixture of concentrated sulphuric and nitric acids. The SWNTs were treated with the acid mixture for 1, 3, and 6 h. FTIR, Raman spectroscopy and TEM revealed the values of carboxylic groups, graphitization and morphology of acid treated SWNTs, respectively. The thermal and mechanical properties and the morphology of nanocomposites were investigated by tensile tests, DMTA, DSC, and SEM.

Effect of Sb2O3 Particle Size and Filling Amount on Crystallization and Mechanical Properties of Sb2O3/PP Composites

2019 ◽  
Vol 956 ◽  
pp. 229-236
Author(s):  
Jian Lin Xu ◽  
Zhou Chen ◽  
Lei Niu ◽  
Cheng Hu Kang ◽  
Xiao Qi Liu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Tensile Strength ◽  
Impact Strength ◽  
Impact Test ◽  
Melt Blending ◽  
Crystallization Properties ◽  
Dsc Characterization ◽  
Pp Composites ◽  
Better Than

In this paper, Sb2O3/PP composite specimens were prepared by ball milling and melt blending. The effects of Sb2O3 particle size and filling amount on the toughening, reinforcing effect and crystallinity of PP composites were analyzed by notch impact test, tensile test, SEM, XRD and DSC characterization. The experimental results show that the filling of Sb2O3 particles can improve the mechanical properties and crystallization properties of Sb2O3/PP composites. With the increase of filling amount of Sb2O3 particles, the tensile strength and impact strength of Sb2O3/PP composite increased first and then decreased. When the content of Sb2O3 is 2 wt.%, the tensile strength and impact strength of Sb2O3/PP composites reach the maximum. When the filling amount is the same, the crystallization and mechanical properties of nanoSb2O3/PP composites are better than those of micron Sb2O3/PP composites.

Effect of the Nucleating Agent BN on Crystallization Properties of P(3HB-co-4HB)

2012 ◽  
Vol 627 ◽  
pp. 827-830
Author(s):  
Bing Xin Sun ◽  
Xu Qiao Feng ◽  
Cheng Zhi Chuai ◽  
Ying Guo ◽  
Si Luo
Keyword(s):  
Crystal Structure ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Nucleating Agent ◽  
Structure And Morphology ◽  
Crystallization Properties

The crystallization properties of P(3HB-co-4HB) modified with nucleating agent BN was studied. DSC is used to analyze the melting crystallization behavior and POM is used to characterize crystal structure and morphology. The results show the incorporation of BN decreased the spherulite size, increased the crystallization rate and improved the crystallization properties of P(3HB-co-4HB).

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