Manasvi Dixit

Morphology, miscibility and mechanical properties of PMMA/PC blends

This study deals with some results on morphology, miscibility and mechanical properties for polymethyl methacrylate/polycarbonate (PMMA/PC) polymer blends prepared by solution casting method at different concentration between 0 and 100 wt%. Dynamic storage modulus and tan δ were measured in a temperature range from 30 to 180°C using dynamical mechanical analyzer (DMA). The value of the storage modulus was found to increase with the addition of the PC in the matrix. Transition temperature of pure PMMA and pure PC is found to be 83.8 and 150°C, respectively. The result shows that the two polymers are miscible for whole concentration of PC in PMMA. The distribution of the phases in the blends was studied through scanning electron microscopy (SEM). Also the mechanical properties like elongation at break and fracture energy of the PMMA/PC blends increase with the increase in concentration of PC in PMMA.

The Structure and Thermomechanical Properties of Blends of Trans-polyisoprene with Cis-polyisoprene

The present work reports the structural and thermomechanical properties of cis- and trans-polyisoprene blends. These blends have been prepared using the solution casting method. The effect of blending on thermomechanical properties such as glass transition temperature, damping and storage modulus and mechanical properties such as toughness, elastic modulus, tensile strength and elongation of present blends has been studied. Besides these, the effect of blending on structure has also been studied. It was observed that elastic moduli, tensile strength and toughness of the TPI/CPI blends decreases with increased CPI percentage. The study also presents a relation between Tg and crystallinity.

Mechanical Characterization of Polymethyl Methacrylate and Polycarbonate Blends

Blends of Poly methyl methacrylate (PMMA) and Polycarbonate (PC) were prepared using solution casting method in five different concentrations (0%, 25%, 50%, 75%, and 100% by weight) using dichloromethane (CH2Cl2) as a solvent. The mechanical properties were studied by Dynamic Mechanical Analyser (DMA). Stress‐strain scan have been used to study the tensile strength and Youngs modulus for these blends. It has been observed that complex modulus decreases with temperature due to the thermal expansion of the film of polymer blend. The result obtained for variation of Tan δ and modulus with concentration indicates about the degree of miscibility of this blends. Glass transition temperature of pure PMMA is found to be at 136 °C because it is highly isotactic in nature. It is observed that Tg of the blend shifts towards the lower temperature with the increase of concentration of PC. Blending of PMMA and PC improves the mechanical properties such as Youngs modulus and tensile strength. The Youngs modulus, ultimate strength and tensile strength increases with the increase in concentration of PC upto 50% and then decreases on further increase in concentration. The value of Youngs modulus and tensile strength is found to be highest at 50% concentration.Blends of Poly methyl methacrylate (PMMA) and Polycarbonate (PC) were prepared using solution casting method in five different concentrations (0%, 25%, 50%, 75%, and 100% by weight) using dichloromethane (CH2Cl2) as a solvent. The mechanical properties were studied by Dynamic Mechanical Analyser (DMA). Stress‐strain scan have been used to study the tensile strength and Youngs modulus for these blends. It has been observed that complex modulus decreases with temperature due to the thermal expansion of the film of polymer blend. The result obtained for variation of Tan δ and modulus with concentration indicates about the degree of miscibility of this blends. Glass transition temperature of pure PMMA is found to be at 136 °C because it is highly isotactic in nature. It is observed that Tg of the blend shifts towards the lower temperature with the increase of concentration of PC. Blending of PMMA and PC improves the mechanical properties such as Youngs modulus and tensile strength. The Youngs modulus, ulti...

Morphological effects on mechanical properties of polystyrene-polyvinylchloride blends

The morphological effects on mechanical properties of polystyrene/polyvinylchloride (PS/PVC) polymer blends were investigated through dynamic mechanical analyzer. Study reveals that the peaks of Tan δ curves of pure PVC and pure PS samples fall at temperatures 58.9 ± 0.2°C and 113.1 ± 0.1°C, respectively. Tan δ curves of 30, 50 and 70-wt% of PVC blends show two peaks indicating the immiscibility of PS/PVC blend. It has been observed that peak falling at lower temperature side shifts towards the higher temperature with the increase of PS concentration and the other one which falls at higher temperature side shifts towards lower temperature side with the increase of PVC concentration in PS/PVC blends. The variation in mechanical performance is attributed to the polymer domain interactions resulting from the different morphologies of various blend compositions.

Thickness-Dependent Mechanical Behaviour of Aluminium-Coated Polyethylene Terephthalate (PET) Films

Mechanical behaviour of aluminium-coated PET films has been investigated through Dynamic Mechanical Analyser. Aluminium is coated on PET substrate by vacuum thermal evaporation method. As thickness of aluminium coating increases from 150 nm to 350 nm, tensile strength decreases from 108.88 MPa to 99.25 MPa. This mechanical behaviour is correlated with microstructure and its evolution with the thickness of aluminium coating. Al-PET film consists of fine globular grains and average grain size increases monotonically with the film thickness. The relative contribution of the grain size to the strength of aluminium thin films is in good agreement with Hall-Patch equation.

Effect of 50 MeV Li+3 Ion Beam Irradiation on Thermomechanical Properties of PMMA/PC Blend Films

This paper reports the effect of the irradiation of 50 MeV Li+3 ions on the thermomechanical properties of PMMA/PC blends. The radiation has been carried out at fluences of 1010 to 1012 ions/cm2 to observe any kind of chain scissoring/crosslinking occurring in the sample. The irradiated as well as the pristine samples have been characterized using X-ray diffraction (XRD), Fourier transform spectroscopy (FTIR), scanning electron microscopy (SEM) and dynamic mechanical analyzer (DMA) to study the induced changes in the structural, morphological and mechanical properties in blend films. The XRD results show an increase in the degree of crystallinity upon ion irradiation at low fluences (≤1011 ions/cm2) and a decrease in crystallinity at high fluences (>1011 ions/cm2), while the FTIR spectra show no appreciable change after irradiation. The mechanical characterization reveals that radiation significantly modifies the mechanical properties and the glass transition temperature of these polymeric blends.

Investigation of Thermo‐mechanical Properties of PMMA

The present paper reports the investigation of thermo‐mechanical properties of Poly(methyl methacrylate) or PMMA. The film of PMMA has been prepared by solution casting method taking tetrahydrofuran (THF) as solvent. So prepared film has been used for the measurement of mechanical properties such as storage modulus, loss modulus, Tan δ and stress strain relation employing Dynamic Mechanical Analyzer (DMA). The glass transition temperature of pure PMMA sample has also been obtained in order to determine its physical state and its influence in other properties such as toughness and stiffness. An effort has also been made to study the storage modulus (E’), loss modulus (E”) and Tan δ in a temperature range from 32°C to 140°C by DMA. It has been observed that storage modulus decreases with temperature due to thermal expansion of films. On the other hand Tan δ increases up to glass transition temperature beyond which it shows decreasing trend towards melting. Glass transition temperature (Tg) is found to be 82...

Phase Transition and Mechanical Properties of PS/PVC/CdS Polymeric Nanocomposites

The present study reports the phase transition temperature and mechanical properties of CdS dispersed PS‐PVC nanocomposite through Dynamic Mechanical Analyzer (DMA). Thick films of polymeric nanocomposites have been synthesized by dispersing nano‐filler particles of CdS in PS/PVC binary blend matrix. The surface morphology of PS/PVC blend samples has been characterized by Scanning Electron Microscopy (SEM) while the nanostructure of the CdS filler in PS/PVC/CdS composite has been ascertained through small angle X‐ray Diffraction (XRD) technique. The phase transition temperature study of PS/PVC polymeric blends reveals that glass transition temperature, Tg, of the PS phase shifts towards lower temperature with the increase in PVC content in the blend whereas for CdS embedded polymeric phases of blends i.e. for PS/PVC/CdS samples, an increase in respective Tg values have been observed. This is suggestive to the fact that phase transition temperature and mechanical properties have been significantly influenc...

Mechanical and Thermal Transport Properties of PMMA/PC and PMMA/PS Blends

The present study deals with some results on mechanical and thermal transport properties of PMMA/PC and PMMA/PS polymer blends prepared by solution casting method at concentrations (0, 25, 50, 75, 100 wt%). Dynamic mechanical Analyser (DMA) and Transient Plane Source (TPS) technique have been used to measure the mechanical properties such as Young’s modulus, toughness, tensile strength, elongation at break and the thermal transport properties like thermal conductivity and thermal diffusivity of PMMA/PC and PMMA/PS blends, respectively, at room as well as elevated temperatures. Also the glass transition temperature (Tg) is determined with the help of DMA of these blended samples. The results show that the mechanical properties of PMMA/PC blends have improved significantly with the increase of PC content in PMMA polymer whereas PMMA/PS blend shows a decreased values of mechanical properties as compared to pure polymers.The Tan δ result shows a single glass transition for PMMA/PC blend which indicates a good...

Thermo-mechanical properties and thermal conductivity of CdS-trans-polyisoprene, polymer nanocomposite

Abstract This paper focuses on the comparative evaluation of the glass transition temperature (Tg), storage modulus and thermal conductivity of trans-polyisoprene (TPI) and CdS-TPI nanocomposite. The CdS nanoparticles synthesized by chemical route are dispersed into TPI using ultrasonic vibrations. Particle size of nanocrystals is obtained from X-ray diffraction and found to be 1.84 nm. Thermo-mechanical properties (Tg and storage modulus) are measured by dynamic mechanical analyzer (DMA), while thermal conductivity is a measured using the transient plane source (TPS) technique. It is observed that glass transition temperature and thermal conductivity are higher while storage modulus and mechanical properties are lower for CdS-TPI nanocomposites than for pure TPI. This has been explained on the basis of structural changes occurring due to introduction of CdS as filler into the TPI.