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Effects of Fillers on the Damping Property of Ethylene Vinyl-Acetate/Polylactic Acid Blends  [PDF]
Xinyan Shi, Lingyan Jia, Yan Ma, Chengliang Li
Journal of Materials Science and Chemical Engineering (MSCE) , 2016, DOI: 10.4236/msce.2016.42010
Abstract: New and high performance damping materials from ethylene vinyl-acetate copolymer (VA content over 40%, shorted as EVM) and polylactic acid (PLA) blends were prepared with dicumyl peroxide (DCP) as the curing agent and triallyl isocyanurate (TAIC) as the curing coagent. The effects of silica, mesoporous silica and glass beads on the damping of the EVM/PLA blends were examined using a dynamic mechanical analyzer (DMA). The microstructures of the silica, mesoporous silica and glass beads were observed by transmission electron microscope (TEM). The dispersion of the fillers in the matrix was studied using a Rubber Process Analyzer (RPA). The results showed that silica filled blend had an effective damping temperature range (EDTR, tan δ > 0.3) of 81, while the mesoporous silica/silica and glass beads/silica filled blends had EDTR of 86 and 85, respectively. Mixtures of mesoporous silica and silica as well as glass beads and silica exhibited a more improved dispersion in the blends than silica alone. Blends filled with mesoporous silica and glass beads retained good mechanical properties as well as improved damping performance.
Effect of Ethylene Carbonate (EC) Plasticizer on Poly (Vinyl Chloride)-Liquid 50% Epoxidised Natural Rubber (LENR50) Based Polymer Electrolyte  [PDF]
M. Y. A. Rahman, A. Ahmad, T. K. Lee, Y. Farina, H. M. Dahlan
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.27111
Abstract: In this research, new thin film of a free standing electrolyte film containing poly(vinyl) chloride (PVC), 50% liquid epoxidized natural rubber (LENR50), Ethylene carbonate (EC) blends as a host for the electrolyte which was doped with lithium perchlorate (LiClO4) as the dopant salt was successfully prepared with solution casting technique. The polymer electrolyte of PVC-LENR50-EC-LiClO4 was characterized using impedance spectroscopy (EIS), scanning electron microscopy (SEM) and Fourier transform infrared (ATR-FTIR). From the EIS results shows that electrolyte exhibited the highest ionic conductivity of 2.1 × 10–7 S●cm–1 at the 30 wt.% of LiClO4. The ionic conductivity result was supported by the morphological studies which revealed the good homogeneity of the PVC-LENR50-EC blends as no phase separation was observed. The smooth surface can ease the mobility of ions in the system complexes. In addition, the formation of micro-pores by introducing lithium salts to the electrolyte also improved the transportation properties of L+ ions in the electrolyte system and hence improving its ionic conductivity. The features of complexation of the electrolytes were studied by ATR-FTIR.
Processing and Characterization of High Density Polyethylene/Ethylene Vinyl Acetate Blends with Different VA Contents  [PDF]
Othman Y. Alothman
Advances in Materials Science and Engineering , 2012, DOI: 10.1155/2012/635693
Abstract: Different series of high density Polyethylene/Ethylene Vinyl Acetate (HDPE/EVA) blends were prepared via melt blending in a corotating intermeshing twin screw extruder. The effects of VA percentage and EVA loading ratio on the thermal, rheological viscoelastic, mechanical, and fracture toughness of the blends were analyzed. The results showed that the addition of EVA to HDPE reduces the thermal, elastic, and viscoelastic properties of the blends. The microscopic examination of the fracture surface confirmed the ductile fracture of HDPE/EVA blends for all blend ratios and VA percentages. Increasing the EVA ratio and VA content caused a significant reduction in the blend crystallinity but had no significant effect on melting temperature. The complex viscosity increased with increasing the percentage of EVA due to the restriction of molecular mobility and reduction of free volume, induced by the addition of EVA. The storage modulus decreased with increasing the EVA ratio and temperature, while it increased with increasing the frequency. Young’s modulus, yield strength, and fracture strain decreased with increasing the EVA ratio. Similarly, the fracture toughness decreased proportional to the EVA percentage. Finally the results indicated that the VA content has significant effects on the mechanical, thermal, and dynamic properties of HDPE/EVA blends. 1. Introduction Polyethylene (PE) is being increasingly used in many industrial and biomedical applications. Its outstanding features such as regular chain structure, combination of low cost and low energy demand for processing, excellent biocompatibility, and good mechanical properties make PE expand its application continuously [1–5]. The superiority of PE products over metal products is attributed to their light weight, high corrosion resistance, and low costs. However, there are some drawbacks with Polyethylene including low environmental stress cracking resistance, low creep resistance, and poor compatibility with various additives which restricted its use for cretin purposes [6, 7]. Therefore, there have been many attempts to improve the properties of polyethylene by blending it with organic or inorganic materials [6–14]. Among these materials is Ethylene Vinyl Acetate (EVA) copolymer, a member of the polyolefin family derived from random copolymerization of Vinyl Acetate (VA) and Ethylene. EVA properties vary substantially as a function of VA content [5]. The VA content has two main effects on polyethylene (PE). First, increasing VA content decreases the crystallinity of PE. Although PE crystallinity
Influence of Poly(vinyl chloride) on Natural Rubber/Chlorosulfonated Polyethylene Blends  [PDF]
Manisara Phiriyawirut, Sawanya Luamlam
Open Journal of Organic Polymer Materials (OJOPM) , 2013, DOI: 10.4236/ojopm.2013.34013
Abstract:

Blend of natural rubber (NR) and chlorosulfonated polyethylene (CSM) was so interesting due to binding of the good oil resistance of CSM, the good mechanical properties and low cost of NR. However, due to the different polarities of two rubbers, phase separation and inferior properties of NR/CSM blend were obtained. The practical way to improve its properties is the addition of the third component to bind both phases of the blend. Effects of poly(vinyl chloride), PVC as compatibilizer on cure characteristics, morphology, mechanical properties and automotive fuel resistance of NR/ CSM blend were investigated. In this contribution, NR/CSM blend with blend ratio of 50/50 was prepared using a two-roll mill, and then vulcanized in a compression mold at 160°C. The PVC content was varied from 1 to 7 phr. It was found that the usage of 7 phr PVC led to improve interaction between NR and CSM phases. Therefore, increase in cure characteristics, mechanical strength and automotive fuel resistance of the blend was observed.

Non-isothermal crystallization kinetics of partially miscible ethylene-vinyl acetate copolymer/low density polyethylene blends
eXPRESS Polymer Letters , 2010, DOI: 10.3144/expresspolymlett.2010.19
Abstract: The non-isothermal crystallization kinetics of ethylene-vinyl acetate copolymer (EVA, 14 wt% vinyl acetate content), low density polyethylene (LDPE) and their binary blends with different blending ratio were investigated via differential scanning calorimetry. Jeziorny theory and Mo’s method were utilized in evaluating the crystallization behavior of both neat materials successfully. In the primary crystallization stage both EVA and LDPE had three-dimensional spherulitic growth mechanism. Apparently the crystallization rate of LDPE was faster than that of EVA at a low cooling rate. Increase in cooling rate limited the spherulites’ growth, which narrowed their rate difference. Influences from blending on the crystallization kinetics of each component in EVA/LDPE mixture were evaluated by Kissinger’s activation energy ( E) and Khanna’s crystallization rate coefficient (CRC). Inter-molecular interaction in the melt increased the E of both EVA and LDPE components at the beginning of cooling. During the primary crystallization stage of LDPE, dilution effect from EVA facilitated the crystal growth in LDPE. Co-crystallization between EVA component and the secondary crystallization stage of LDPE component also increased the CRC of EVA. In blend of EVA/LDPE = 7/3, LDPE obtained the maximal CRC value of 174.2 h–1. Results obtained from various approaches accorded well with each other, which insured the rationality of conclusion.
Miscibility Behavior of Poly Ethylene Glycol or Poly Ethylene Succinate/Chlorinated Poly Vinyl Chloride Blends Studied by Dielectric Relaxation Spectroscopy  [PDF]
Taha A. Hanafy
Advances in Materials Physics and Chemistry (AMPC) , 2013, DOI: 10.4236/ampc.2013.32015
Abstract:

The miscibility of chlorinated poly vinyl chloride (CPVC) and poly ethylene glycol (PEG) or poly ethylene succinate (PES) had been investigated using dielectric relaxation spectroscopy (DRS) over frequency and temperature ranges; 10 kHz - 4 MHz and 300 - 450 K, respectively. Three relaxation processes namely ρ-, α’-, and α-relaxation processes were observed for tan(δ) and the electric modulus M\" of pure components and blends. The first one was attributed to the space charge polarization or the Maxwell-Wagner polarization. The second one was related to the amorphous regions located between the lamellar crystal stacks. The third one was due to the micro-Brownian motion of CPVC main chains. This process was found to be dependent in respect of temperature and frequency. The molecular dynamics of α-relaxation process were influenced by blending, i.e., the dielectric strength (De), the peak broadness, and the peak maximum of tan(δ) were found to be compositional dependent. Electric modulus analysis reveals that there is a role of electrode polarization for the dielectric relaxation.

EFFECTS OF COMPATIBILIZERS ON MORPHOLOGY AND TOUGHNESS OF NYLON 6/ETHYLENE-VINYL ACETATE COPOLYMER (EVA) BLENDS
增容剂对尼龙6/乙烯^=醋酸乙烯酯共聚物共混合金的亚微形态与力…

WANG Xiaodong,JIM Dong Gil,JIN Riguang,
汪晓东
,金东吉,金日光

材料研究学报 , 1996,
Abstract: Blends of Nylon 6 matrix (800mg/g) and ethylene-vinyl acetate copolymer (EVA) impact modifier (200mg/g) were prepared by reactive extrusion with compatibilizers with fuctional carboxyl group,included one of ethylene-acrylic acid copolymer (Nucrel) and eth
Low frequency dielectric relaxation processes and ionic conductivity of montmorillonite clay nanoparticles colloidal suspension in poly(vinyl pyrrolidone) ethylene glycol blends
eXPRESS Polymer Letters , 2008, DOI: 10.3144/expresspolymlett.2008.93
Abstract: The dielectric dispersion behaviour of montmorillonite (MMT) clay nanoparticles colloidal suspension in poly(vinyl pyrrolidone)-ethylene glycol (PVP-EG) blends were investigated over the frequency range 20 Hz to 1 MHz at 30°C. The 0, 1, 2, 3, 5 and 10 wt% MMT clay concentration of the weight of total solute (MMT+PVP) were prepared in PVP-EG blends using EG as solvent. The complex relative dielectric function, alternating current (ac) electrical conductivity, electric modulus and impedance spectra of these materials show the relaxation processes corresponding to the micro-Brownian motion of PVP chain, ion conduction and electrode polarization phenomena. The real part of ac conductivity spectra of these materials obeys Jonscher power law σ′(ω) =σdc + Aωn in upper frequency end of the measurement, whereas dispersion in lower frequency end confirms the presence of electrode polarization effect. It was observed that the increase of clay concentration in the PVP-EG blends significantly increases the ac conductivity values, and simultaneously reduces the ionic conductivity relaxation time and electric double layer relaxation time, which suggests that PVP segmental dynamics and ionic motion are strongly coupled. The intercalation of EG structures in clay galleries and exfoliation of clay sheets by adsorption of PVP-EG structures on clay surfaces are discussed by considering the hydrogen bonding interactions between the hydroxyl group (–OH) of EG molecules, carbonyl group (C=O) of PVP monomer units, and the hydroxylated aluminate surfaces of the MMT clay particles. Results suggest that the colloidal suspension of MMT clay nano particles in the PVP-EG blends provide a convenient way to obtain an electrolyte solution with tailored electrical conduction properties.
Adhesion Properties of Acrylonitrile-Butadiene Rubber/Standard Malaysian Rubber Blend Based Pressure-Sensitive Adhesive  [PDF]
B. T. Poh,J. Lamaming,G. S. Tay
Journal of Coatings , 2014, DOI: 10.1155/2014/369352
Abstract: Viscosity and adhesion properties of NBR/SMR L blend based pressure-sensitive adhesive were investigated using coumarone-indene resin, toluene, and poly(ethylene terephthalate) (PET) as tackifier, solvent, and coating substrate, respectively. Coumarone-indene resin content was fixed at 40 parts per hundred parts of rubber (phr) in the adhesive formulation. The ratio of NBR/SMR L blend used was 0, 20, 40, 60, 80, and 100% of NBR content. Four different thicknesses, that is, 30, 60, 90, and 120?μm, were used to coat the PET film. The viscosity of adhesive was determined by a Brookfield viscometer, whereas loop tack, peel strength, and shear strength were measured using a Lloyd Adhesion Tester operating at 30?cm/min. Result indicates that the viscosity, loop tack, and shear strength of blend adhesives increase with % NBR. However, for peel strength, it indicates a maximum at 40% NBR blend ratio for the three modes of peel tests. In all cases, 120?μm coated sample consistently exhibits the highest adhesion values compared to the other coating thicknesses, an observation which is associated with the higher volume of adhesive in the former system. 1. Introduction Many studies on rubber-based adhesives involve a single component rubber as the elastomer in the adhesive formulation. These include the study of viscoelastic properties of natural rubber pressure-sensitive adhesive using acrylic resin as a tackifier [1], the effects of miscibility and viscoelasticity on peel strength and shear creep resistance of natural-rubber-based pressure-sensitive adhesives [2, 3], and modelling the peel performance of natural rubber-based pressure-sensitive adhesives at different rates of testing [4, 5]. Thitithammawong et al. [6] discussed the preparation and properties of chlorinated epoxidized natural rubber latex and its latex-based adhesives. On the other hand, Varghese and Thachil [7] studied the adhesive properties of neoprene-phenolic blends. However, study on the adhesive properties of rubber-based blends is rarely reported. Phillips et al. [8, 9] have studied the singlet oxygen generation and adhesive properties in polymer blends adhesives using block copolymers as the elastomers. Smitthipong et al. [10] investigated the self-adhesion of immiscible polyisoprene rubber-hydrogenated acrylonitrile butadiene rubber blends, whereas Magida et al. [11] reported the pressure-sensitive adhesive applications of compatible blend of styrene-vinyl acetate copolymer/natural rubber latex. Meanwhile, da Silva et al. [12] found that a single resin will improve the adhesion property
On the influence of nucleation on the toughness of iPP/EPR blends with different rubber molecular architectures
eXPRESS Polymer Letters , 2008, DOI: 10.3144/expresspolymlett.2008.47
Abstract: The influence of α-and β-nucleating agents on the fracture performance of two different 32 wt% rubber modified isotactic Polypropylene (iPP) reactor blends is discussed as a function of the phase morphology of the investigated systems. Nucleation for systems with a large inter-particle distance was found to have only a limited impact on the temperature at which the ductile-brittle transition occurs, negative for α-nucleated blends, almost negligible for β-nucleated resins. For blends exhibiting a small inter-particular distance between their ethylene-propylene rubber (EPR) phase, toughness was promoted slightly by α-nucleation and to a large extent by β-nucleation as compared to a non-nucleated reference. These findings raise the importance of mechanistic synergies between the rubbery phase and the matrix to maximize the fracture resistance of blends.
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