Biodegradable Polymers and Polylactic Acid Synthesis
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Questions and Answers

What is the temperature range of polylactic acid's melting point?

  • 180 - 190 °C
  • 150 - 160 °C
  • 120 - 130 °C
  • 157 - 170 °C (correct)

    • What is the method of synthesizing polylactic acid through ring-opening polymerization?

  • Using only solution method of polymerization
  • With the presence of metal catalysts (correct)
  • Using only suspension method of polymerization
  • Without the presence of metal catalysts

    • What is a property of polylactic acid besides being biodegradable and biocompatible?

  • Being non-reinforceable with fillers
  • Having low melting temperature
  • Conducting electrical signals
  • Imparting good mechanical properties (correct)

    • Which of the following is NOT an application of polylactic acid?

    <p>Production of electronic components</p> Signup and view all the answers

    What is the purpose of a sensor?

    <p>To detect physical parameters and convert them into electrical signals</p> Signup and view all the answers

    What is polylactic acid synthesized from?

    <p>Fermented plant starch</p> Signup and view all the answers

    What is a possible reinforcement material for polylactic acid?

    <p>Carbon fibers</p> Signup and view all the answers

    In which fields is polylactic acid widely used?

    <p>Biomedical and pharmaceutical fields</p> Signup and view all the answers

    What type of molecules are pharmaceuticals, such as diclofenac, often comprised of?

    <p>Complex organic molecules</p> Signup and view all the answers

    What is the working electrode material used in the electrochemical sensor for detecting diclofenac?

    <p>Carbon Paste with MWCNT or Graphene</p> Signup and view all the answers

    What is the outcome of the oxidation reaction of diclofenac on the surface of the sensing electrode?

    <p>Release of electrons to form radical intermediates</p> Signup and view all the answers

    Why is the detection of polycyclic aromatic hydrocarbons (PAHs) important?

    <p>Because they are carcinogenic and mutagenic compounds</p> Signup and view all the answers

    What is the material used to coat the graphite carbon in the electrochemical sensor for detecting 1-Hydroxypyrene?

    <p>PAMAM/Cr-MOF/GO composite</p> Signup and view all the answers

    What is the operating voltage range of the electrochemical sensor for detecting 1-Hydroxypyrene?

    <p>+0.7 to -0.5V</p> Signup and view all the answers

    What is the primary route of exposure to polycyclic aromatic hydrocarbons (PAHs)?

    <p>Through respiration and diet</p> Signup and view all the answers

    What is the purpose of electrochemical sensors in detecting pharmaceuticals and PAHs?

    <p>To monitor their concentration and know their toxic effects</p> Signup and view all the answers

    What is the primary method of forming a polymer?

    <p>Through covalent bonding</p> Signup and view all the answers

    What is the characteristic of Kevlar that makes it resistant to fire and chemical attack?

    <p>High chemical stability</p> Signup and view all the answers

    What is the definition of a monomer?

    <p>A simple molecule with two or more bonding sites</p> Signup and view all the answers

    What is the characteristic of Kevlar that makes it suitable for use in tyres and industrial cables?

    <p>High impact resistance</p> Signup and view all the answers

    What is the process by which Kevlar is synthesized?

    <p>Condensation polymerization</p> Signup and view all the answers

    What is the characteristic of conducting polymers?

    <p>High electrical conductivity</p> Signup and view all the answers

    What is the use of Kevlar in clothing?

    <p>All of the above</p> Signup and view all the answers

    What is the benefit of Kevlar's high crystallinity?

    <p>It increases its resistance to high temperature</p> Signup and view all the answers

    Study Notes

    Biodegradable Polymers

    • Biodegradable polymers are materials that deteriorate and completely degrade when exposed to microorganisms, aerobic, and anaerobic processes.

    Polylactic Acid

    • Can be synthesized by two methods: direct condensation of lactic acid at 200 °C and ring-opening polymerization of lactide in the presence of metal catalysts.
    • Properties: • Thermoplastic • Melting temperature: 157 – 170 °C • Good mechanical properties, barrier behavior, and excellent shaping and molding properties • Good optical property • Biodegradable, biocompatible, and compostable • Can reinforce fillers
    • Applications: • Widely used in biomedical and pharmaceutical fields due to biocompatibility and bioresorbable properties • Used in controlled drug release, prostheses, sutures, medical implants, and scaffolds for tissue engineering • Can be reinforced with carbon fibers to produce composites of high mechanical strength • Used as a food packaging material

    Sensors

    • A device that detects a physical parameter of interest (e.g. heat, light, sound) and converts it into an electrical signal.

    Polymer Technology

    • A polymer is a large molecule made up of small and simple molecules joined together chemically through covalent bonds.
    • A monomer is a simple molecule with two or more bonding sites that forms covalent linkages with other monomer molecules to form a macromolecule.

    Composite Polymers

    • A combination of two or more distinct components to form a new class of material suitable for structural applications.

    Kevlar

    • Synthesized from 1,4-phenylenediamine and terephthaloyl chloride through condensation polymerization.
    • Properties: • Extremely lightweight • Highly crystalline • High impact resistance • High temperature resistance • Resistant to fire and chemical attack • Exhibits high chemical stability • Shows excellent stability over a wide range of temperatures for prolonged periods • Possesses high tensile strength and modulus
    • Applications: • Used to make tires, racing sails for boats, and bulletproof vests • Used in industrial cables and brake linings • Used in the construction of aircraft and space vehicles • Used in the manufacturing of gloves, jackets, and other articles of clothing

    Conducting Polymers

    • An organic polymer with a delocalized pi-electron system, having electrical conductance of the same order as a conductor.
    • Examples: Diclofenac detection using a carbon-based sensor.

    Working Principle of Conducting Polymers

    • Working electrode: Carbon Paste with MWCNT or Graphene
    • Counter Electrode: Carbon Paste or Platinum
    • Reference Electrode: Ag/AgCl
    • Process: Screen Printing Technique on PVC substrate
    • Oxidation reaction occurs on the surface of the sensing electrode, releasing electrons to form radical intermediates.

    Electrochemical Sensors for Hydrocarbons (1-Hydroxypyrene)

    • Working electrode: PAMAM/Cr-MOF/GO(Composite)
    • Counter Electrode: Platinum
    • Reference Electrode: Ag/AgCl
    • Operating Voltage: +0.7 to -0.5V
    • Electrochemical sensors are used to detect 1-Hydroxypyrene, a carcinogenic and mutagenic compound.

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    Description

    This quiz covers the definition and characteristics of biodegradable polymers, including their synthesis and properties, with a focus on Polylactic acid.

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