scholarly journals Effects of Dynamic Crosslinking on Crystallization, Structure and Mechanical Property of Ethylene-Octene Elastomer/EPDM Blends

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 139
Author(s):  
Yuan-Xia Wang ◽  
Chen-Chen Wang ◽  
Ying Shi ◽  
Li-Zhi Liu ◽  
Nan Bai ◽  
...  
Keyword(s):  
Phase Separation ◽  
Mechanical Analysis ◽  
Ethylene Propylene Diene Monomer ◽  
Elongation At Break ◽  
Polyolefin Elastomer ◽  
Higher Temperature ◽  
Rubber Phase ◽  
Conversion Temperature ◽  
Crystallization Structure ◽  
Thermoplastic Properties

The dynamic crosslinking method has been widely used to prepare rubber/plastic blends with thermoplastic properties, and the rubber phase is crosslinked in these blends. Both polyolefin elastomer (POE) and ethylene-propylene-diene monomer rubber (EPDM) can be crosslinked, which is different from usual dynamic crosslinking components. In this paper, dynamic crosslinked POE/EPDM blends were prepared. For POE/EPDM blends without dynamic crosslinking, EPDM can play a nucleation role, leading to POE crystallizing at a higher temperature. After dynamic crosslinking, the crosslinking points hinder the mobility of POE chains, resulting in smaller crystals, but having too many crosslinking points suppresses POE crystallization. Synchrotron radiation studies show that phase separation occurs and phase regions form in non-crosslinked blends. After crosslinking, crosslinking points connecting EPDM and part of POE chains, enabling more POE to enter the EPDM phase and thus weakening phase separation, indicates that dynamic crosslinking improves the compatibility of POE/EPDM, also evidenced by a lower β conversion temperature and higher α conversion temperature than neat POE from dynamic mechanical analysis. Moreover, crosslinking networks hinder the crystal fragmentation during stretching and provide higher strength, resulting in 8.3% higher tensile strength of a 10 wt% EPDM blend than neat POE and almost the same elongation at break. Though excessive crosslinking points offer higher strength, they weaken the elongation at break.

A Study on the Blends of Epoxy/Polybutadiene and the Application to the Encapsulation of a Capacitor

1992 ◽  
Vol 274 ◽  
Author(s):  
Zhongyuan Ren ◽  
Liying Qui
Keyword(s):  
Phase Separation ◽  
Dynamic Mechanical Analysis ◽  
Low Temperatures ◽  
Epoxy Resins ◽  
Mechanical Analysis ◽  
Dynamic Mechanical

ABSTRACTThis paper describes the blends of epoxy/polybutadiene and the application of the blends to the encapsulation of capacitors. Experiments showed that the hydroxy-carboxyl terminated polybutadiene (HCTPB) had a good toughening effect on epoxy resins, and the blends of epoxy/HTPB or epoxy/HCTPB had good craze resistance at low temperatures. The phase separation and dynamic mechanical analysis of these blends are discussed below.

scholarly journals Structure and Properties of Polyoxymethylene/Silver/Maleic Anhydride-Grafted Polyolefin Elastomer Ternary Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1954
Author(s):  
Yang Liu ◽  
Xun Zhang ◽  
Quanxin Gao ◽  
Hongliang Huang ◽  
Yongli Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Maleic Anhydride ◽  
Ag Nanoparticles ◽  
Decomposition Temperature ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Maximum Value ◽  
Polyolefin Elastomer ◽  
Local Defects

In the present study, silver (Ag) nanoparticles and maleic anhydride-grafted polyolefin elastomer (MAH-g-POE) were used as enhancement additives to improve the performance of the polyoxymethylene (POM) homopolymer. Specifically, the POM/Ag/MAH-g-POE ternary nanocomposites with varying Ag nanoparticles and MAH-g-POE contents were prepared by a melt mixing method. The effects of the additives on the microstructure, thermal stability, crystallization behavior, mechanical properties, and dynamic mechanical thermal properties of the ternary nanocomposites were studied. It was found that the MAH-g-POE played a role in the bridging of the Ag nanoparticles and POM matrix and improved the interfacial adhesion between the Ag nanoparticles and POM matrix, owing to the good compatibility between Ag/MAH-g-POE and the POM matrix. Moreover, it was found that the combined addition of Ag nanoparticles and MAH-g-POE significantly enhanced the thermal stability, crystallization properties, and mechanical properties of the POM/Ag/MAH-g-POE ternary nanocomposites. When the Ag/MAH-g-POE content was 1 wt.%, the tensile strength reached the maximum value of 54.78 MPa. In addition, when the Ag/MAH-g-POE content increased to 15wt.%, the elongation at break reached the maximum value of 64.02%. However, when the Ag/MAH-g-POE content further increased to 20 wt.%, the elongation at break decreased again, which could be attributed to the aggregation of excessive Ag nanoparticles forming local defects in the POM/Ag/MAH-g-POE ternary nanocomposites. Furthermore, when the Ag/MAH-g-POE content was 20 wt.%, the maximum decomposition temperature of POM/Ag/MAH-g-POE ternary nanocomposites was 398.22 °C, which was 71.39 °C higher than that of pure POM. However, compared with POM, the storage modulus of POM/Ag/MAH-g-POE ternary nanocomposites decreased with the Ag/MAH-g-POE content, because the MAH-g-POE elastomer could reduce the rigidity of POM.

Fine structure formation and physical properties of poly(butylene terephthalate) fibres in high-speed melt spinning

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Hee Lee Sun ◽  
Hou Kim Kyoung ◽  
Kikutani Takeshi ◽  
Hok Cho Hyun
Keyword(s):  
Fine Structure ◽  
Physical Properties ◽  
Structure Formation ◽  
High Speed ◽  
Melt Spinning ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Butylene Terephthalate ◽  
Initial Modulus ◽  
Higher Temperature

Abstract Poly(butylene terephthalate) (PBT) fibres were obtained by high-speed melt spinning up to a take-up velocity of 8 km/min. Fine structure formation and physical properties of these fibres were investigated. The increase of take-up velocity caused raises in both density and birefringence. In wide-angle X-ray diffraction equatorial profiles, the increase of take-up velocity can be observed in the (010) and (100) reflections of β-crystals; the reflection peaks are the sharpest at a take-up velocity of 6 km/min. The initial modulus of the fibres arises when the fraction of β-crystals is increased, while the tenacity depends more on the fraction of α-crystals, i.e., the total crystallinity. Thermal properties of high-speed spun PBT fibres were measured with differential scanning calorimetry, dynamic mechanical and thermo-mechanical analysis, etc. Endothermic curves become sharper with increasing take-up velocity, and endothermic melting peaks are shifted to higher temperature. Crystal structures are well developed in fibres obtained at higher take-up velocities. The tan δ peaks of PBT fibres tend to shift to higher temperature and the peak intensity is decreased with increasing take-up velocity, i.e., the packing density of PBT fibres is high when the take-up velocity and thus the orientation of amorphous regions is increased. The shrinkage has a tendency to decrease with increasing take-up velocity.

Influence of the micro-structural factors upon thermal and mechanical properties of various bag leathers

2017 ◽  
Vol 52 (3) ◽  
pp. 167-176 ◽  
Author(s):  
AK Mondal ◽  
PK Chattopadhyay
Keyword(s):  
Mechanical Properties ◽  
Morphological Characteristics ◽  
Crosslinking Density ◽  
Structural Factors ◽  
Melamine Formaldehyde ◽  
Elongation At Break ◽  
Indian Origin ◽  
Higher Temperature ◽  
Temperature And Pressure ◽  
Vegetable Tannins

Four different bag leathers, such as, Sheep Bag Leather (SBL), Buffalo Vegetable Tanned Leather (BVTL), Cow Drum Dyed Dry Milled Leather (CDDDML), and Cow Crocodile Print Leather (CCPL), were processed by different methods from respective wet-blues of Indian origin. Thermal degradation pro?le and mechanical properties of the samples were evaluated, and crosslink densities of each sample were measured by ?tment of Mooney-Rivlin equation on stress-strain plots. Morphological characteristics (e.g. ?bre structure, ?bre thickness, splitting etc.) of all the specimens were investigated by image analyses of SEM photomicrographs. The highest crosslinking density for BVTL was attributed to its higher ?bre and ?bril thicknesses coupled with rigorous retanning by vegetable tannins and syntans. Embossing at higher temperature and pressure reduced CCPL’s elongation-at-break value and hence stretchiness possibly due to the development of set properties within the CCPL matrix. SBL was noted to contain huge void spaces that increased its stretchiness, and melamine formaldehyde syntans showed pronounced in?uence in increasing the thermal resistance of both CCPL and CDDDML.Bangladesh J. Sci. Ind. Res. 52(3), 167-176, 2017

Toughening of Polypropylene Highly Filled with Aluminum Hydroxide

2005 ◽  
Vol 13 (2) ◽  
pp. 139-150 ◽  
Author(s):  
Zhanpai Su ◽  
Pingkai Jiang ◽  
Qiang Li ◽  
Ping Wei ◽  
Yong Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Aluminum Hydroxide ◽  
Interfacial Adhesion ◽  
Ethylene Propylene Diene Monomer ◽  
The Matrix ◽  
Izod Impact ◽  
Rubbery Phase ◽  
Rubber Phase ◽  
Toughening Agent

The flame retardant and mechanical properties of polypropylene (PP), highly filled with aluminum hydroxide (Al(OH)3) and toughened with ethylene propylene diene monomer (EPDM) and zinc neutralized sulfated EPDM ionomer (Zn-S-EPDM), were studied along with their morphology. The PP matrix when highly filled with Al(OH)3 particles can achieve an adequate level of flame retardancy, but there is a decrease in the mechanical properties because of inadequate adhesion between the Al(OH)3 particles and the PP matrix and the strong tendency of the filler to agglomerate. The rubber incorporated in the PP/Al(OH)3 composites has two roles: as compatibilizer and toughening agent. Although ordinary EPDM significantly improves the Izod impact strength of the composites, the tensile properties are much worse because of the weak interfacial adhesion between the modifier and the matrix. Using Zn-S-EPDM instead EPDM, the tensile properties are much improved with only a slight decrease in toughness, because of improvements in the interfacial adhesion between modifier and matrix. SEM micrographs show that the rubber phase is dispersed in the continuous PP matrix and that most Al(OH)3 particles are uniformly distributed in the rubbery phase. Larger, obviously rubbery, domains can be seen in the PP/EPDM/Al(OH)3 ternary composites. Much finer rubbery domains were found in the PP/Zn-S-EPDM/Al(OH)3 composites.

Reaction-induced phase separation in poly(butylene terephthalate)-epoxy systems: 1. Conversion-temperature transformation diagrams

Polymer ◽  
1996 ◽  
Vol 37 (14) ◽  
pp. 3079-3085 ◽  
Author(s):  
P.A. Oyanguren ◽  
P.M. Frontini ◽  
R.J.J. Williams ◽  
E. Girard-Reydet ◽  
J.P. Pascault
Keyword(s):  
Phase Separation ◽  
Butylene Terephthalate ◽  
Temperature Transformation ◽  
Transformation Diagrams ◽  
Epoxy Systems ◽  
Conversion Temperature

scholarly journals Comparison of Precipitated Calcium Carbonate/Polylactic Acid and Halloysite/Polylactic Acid Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Xuetao Shi ◽  
Guangcheng Zhang ◽  
Cristina Siligardi ◽  
Guido Ori ◽  
Andrea Lazzeri
Keyword(s):  
Glass Transition ◽  
Calcium Carbonate ◽  
Polylactic Acid ◽  
Halloysite Nanotubes ◽  
Mechanical Analysis ◽  
Precipitated Calcium Carbonate ◽  
Dynamical Mechanical Analysis ◽  
Elongation At Break ◽  
Ultimate Deformation ◽  
Tensile Performance

PLA nanocomposites with stearate coated precipitated calcium carbonate (PCC) and halloysite natural nanotubes (HNT) were prepared by melt extrusion. The crystallization behavior, mechanical properties, thermal dynamical mechanical analysis (DMTA), and the morphology of the PCC/PLA, HNT/PLA, and HNT/PCC/PLA composites were discussed. Compared to halloysite nanotubes, PCC nanoparticles showed a better nucleating effect, which decreased both the glass transition and cold crystallization temperatures. The tensile performance of PLA composites showed that the addition of inorganic nanofillers increased Young’s modulus but decreased tensile strength. More interestingly, PLA composites with PCC particles exhibited an effectively increased elongation at break with respect to pure PLA, while HNT/PLA showed a decreased ultimate deformation of composites. DMTA results indicated that PLA composites had a similar storage modulus at temperatures below the glass transition and the addition of nanofillers into PLA causedTgto shift to lower temperatures by about 3°C. The morphological analysis of fractures surface of PLA nanocomposites showed good dispersion of nanofillers, formation of microvoids, and larger plastic deformation of the PLA matrix when the PCC particles were added, while a strong aggregation was noticed in composites with HNT nanofillers, which has been attributed to a nonoptimal surface coating.

scholarly journals Study on the Influence of Processing Oil on the Physical Mechanical Properties and Adhesion of Ethylene Propylene Diene Monomer (EPDM) Rubbers to Polyester Fabrics

2020 ◽  
Vol 36 (2) ◽  
Author(s):  
Nguyen Thanh Liem ◽  
Nguyen Pham Duy Linh ◽  
Nguyen Huy Tung ◽  
Bach Trong Phuc ◽  
Bui Chuong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Resistance ◽  
Mechanical And Thermal Properties ◽  
Ethylene Propylene Diene Monomer ◽  
Elongation At Break ◽  
High Thermal Resistance ◽  
The Mean ◽  
Peel Force ◽  
Paraffinic Oil

In this paper, the influence of paraffinic oil on the physical mechanical and thermal properties of three EPDM rubbers types Buna EP T.6465, Keltan 5260Q and Keltan 6160 D have been investigated. The results showed that the tensile strength and the elongation at break of Keltan 5260Q and Keltan 6160 D with 10 phr paraffinic oil represent the improvement of 57.8% to 57.6% and 71% to 81% respectively, compared to EPDM rubbers without paraffinic oil. The mean peel force of EPDM keltan 6260D with 10 phr paraffinic oil loaded is about 36% and 32.5% higher than that of keltan 5260Q and EP.T 6465 respectively. Beside that at the suitable paraffinic oil contents, the thermal resistance of Keltan 5260 Q and 6160D seems to be a little higher than that of without processing oil and these EPDM rubbers are suitable for application to high thermal resistance rubber products.

scholarly journals Effect of Mechanical Properties in Enhanced Polymeric Blend Membranes

2021 ◽  
Vol 64 (2) ◽  
pp. 97-102
Author(s):  
Asim Mushtaq ◽  
Hilmi Bin Mukhtar ◽  
Azmi Mohd Shariff
Keyword(s):  
Mechanical Properties ◽  
Polymeric Material ◽  
Polyvinyl Acetate ◽  
Glassy Polymer ◽  
Mechanical Analysis ◽  
Elongation At Break ◽  
Dimethyl Acetamide ◽  
Analysis Technique ◽  
Blend Membranes ◽  
Polymeric Blend

This study was carried out to evaluate the effect of blending the rubbery and glassy polymer with an alkanolamine on the mechanical properties. Due to the intrinsic properties of glassy polysulfone (PSU) and rubbery polyvinyl acetate (PVAc), optimizing their properties by blending both polymers is expected to address the shortage. The enhanced polymeric blend membrane (EPBM) was developed by varying the composition of PVAc ranging from 5 to 20 wt. % with 95 to 80 wt. % base PSU in dimethyl- acetamide (DMAc) solvent. The DEA amine composition was added to the blend and kept at 10 wt. % over solvent. The tensile analysis technique is utilized to evaluate the mechanical behaviour of a polymeric material which comprises the deformation of the polymeric material underneath the effect of an applied force prior to failure. The mechanical analysis showed improvement in tensile strength, Young's modulus and elongation at break properties with the increase in PVAc/DEA composition in the enhanced polymeric blend membranes. The elongation at break property increased with an increase in the amine contents which indicated the flexibility of the EPBM. In addition, the mechanical analysis revealed remarkable enhancement in the mechanical properties of the EPBM which might be attributed to the robust interactions among the PSU blend with PVAc and DEA.

scholarly journals Structure–Properties Relationship in Waterborne Poly(Urethane-Urea)s Synthesized with Dimethylolpropionic Acid (DMPA) Internal Emulsifier Added before, during and after Prepolymer Formation

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2478
Author(s):  
Mónica Fuensanta ◽  
Abbas Khoshnood ◽  
José Miguel Martín-Martínez
Keyword(s):  
Particle Size ◽  
Phase Separation ◽  
Ph Value ◽  
Peel Test ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Adhesion Properties ◽  
Structural Differences ◽  
Higher Temperature ◽  
Structure Properties

Dimethylolpropionic acid (DMPA) internal emulsifier has been added before, during and after prepolymer formation in the synthesis of waterborne poly(urethane-urea)s (PUDs) and their structure–properties relationships have been assessed. PUDs were characterized by pH, viscosity and particle size measurements, and the structure of the poly(urethane-urea) (PU) films was assessed by infra-red spectroscopy, differential scanning calorimetry, X-ray diffraction, thermal gravimetric analysis, plate–plate rheology and dynamic mechanical thermal analysis. The adhesion properties of the PUDs were measured by cross-hatch adhesion and T-peel test. The lowest pH value and the highest mean particle size were found in the PUD made by adding DMPA after prepolymer formation, all PUDs showed relatively ample mono-modal particle size distributions. The highest viscosity and noticeable shear thinning were obtained in the PUD made by adding DMPA during prepolymer formation. Depending on the stage of addition of DMPA, the length of the prepolymer varied and the PU films showed different degree of micro-phase separation. Because the shortest prepolymer was formed in the PU made with DMPA added before prepolymer, this PU film showed the lowest storage moduli and early melting indicating higher degree of micro-phase separation. The highest storage modulus, later melting, higher temperature and lower modulus at the cross between the storage and loss moduli corresponded to the PU made by adding DMPA after prepolymer formation, because the longer prepolymer produced during synthesis. The lowest thermal stability corresponded to the PU made by adding DMPA during prepolymer formation and the structures of all PU films were dominated by the soft domains, the main structural differences derived from the hard domains. Whereas DMPA-isophorone diisocyanate (IPDI) urethane and urea hard domains were created in the PU film made by adding DMPA during prepolymer formation, the other PU films showed DMPA-IPDI, polyester-IPDI and two different DMPA-IPDI-polyester hard domains. Finally, the adhesion properties of the PUDs and PU coatings were excellent and they were not influenced by the structural differences caused by adding DMPA in different stages of the synthesis.

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