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Showing posts with the label Polystyrene

Modelling the Creep Curves of β-BOPP Film

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       JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract The effect of annealing on the creep and recovery properties of β -BOPP film was studied. The creep resistance can be improved obviously by annealing, the modification becomes better with elongating the duration. Four-parameter Burger model and Weibull distribution function well described such cases. Keywords:  BOPP Film; Creep; Fitting; Burger Model; Weibull Distribution Function Introduction Biaxially oriented polypropylene (BOPP) film has become a widely used film material because of its light weight, good transparency, moisture-proof, non-toxic and simple preparation process. When the content of β crystal in BOPP is increased, the toughness and thermal deformation resistance of BOPP film is greatly improved such that its application scope is expanded. However, its internal structure will undergo such complex changes as the movement of chain segments, the unwinding of molecular cha...

A New Composition of High Heat General Purpose Polystyrene (High Heat GPPS) Resin

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       JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract A new composition of high heat general-purpose polystyrene (High heat GPPS) resin synthesis is discussed. The new composition of resin involves addition of cross-linker/comonomer in very low concentration during synthesis process. Commercially available vinyl cross-linkers like divinylbenzene (DVB), Ethylene dimethacrylate (EDM), Tricycle (5.2.1.02,6) decanedimethanol diacrylate (TDDDA), Dicyclopentadiene (DCPD) and vinyl comonomer like maleic anhydride, α-methylstyrene have been evaluated via bulk polymerization method. DVB showed enhancement in the heat distortion temperature (HDT), vicat softening temperature (VST) & melt flow index (MFI) compared to the benchmark grade of GPPS, whereas other mechanical and impact properties remained same or better than benchmark grade under identical methods of measurement. Keywords:  Divinylbenzene; Cross-linked; Branching; Polymerization; He...

Experiment: Make Binding Forces Visible- Molecular Binding Forces, Recycling/Reuse, Life Cycle Engineering (LCE)

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       JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract A very simple experiment shows students the difference between primary and secondary molecular binding forces. Use an empty plastic cup for milk, yoghurt or coffee and destroy it by pressing the cup together. You will watch cracks only longitudinal the cup. Try to break the cup horizontally you will fail. What you observe are the secondary binding forces between the molecules oriented along the length of the cup versus the primary binding forces perpendicular to the long side of cup. Keywords:  Molecular Binding Forces; Recycling/Reuse; Life Cycle Engineering (LCE) Introduction What should be found/investigated ? [answer: Are the primary molecular binding forces (within the molecular chain acting binding forces, i.e. between primarily connected atoms) actually significantly stronger than the secondary binding forces (between molecules acting forces)? How can a yoghurt cup be reused in...

A Comparative Study of Multiwalled Carbon Nanotube Based Polystyrene and Toughened Polycarbonate Nanocomposites-Juniper Publishers

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Authored by Nisha Bagotia                                                                               Abstract The main objective of this article is to describe the effect of different length (aspect ratio) of carbon nanotubes (CNTs) on the electrical conductivity and electromagnetic shielding effectiveness of polystyrene/l-MWCNT and toughened polycarbonate/s-MWCNT composites. Long and short MWCNTs having aspect ratio of ~666 - 1333 and ~157 respectively were used for melt-mixed with polystyrene and toughened polycarbonate in a micro compounder. The uniform dispersion of MWCNT in matrix was confirmed b...