Polymer Science Overview

<p>They do not degrade in natural environments. (D)</p> Signup and view all the answers

<p>Creating food packaging materials. (D)</p> Signup and view all the answers

<p>They are highly stretchable. (D)</p> Signup and view all the answers

<p>120°C (A)</p> Signup and view all the answers

<p>Lack of natural sources. (C)</p> Signup and view all the answers

<p>It shows variation in color. (B)</p> Signup and view all the answers

<p>As a conductor in semiconductors. (C)</p> Signup and view all the answers

<p>They break down into natural substances by microorganisms. (A)</p> Signup and view all the answers

<p>Corn-based polylactic acid (PLA). (D)</p> Signup and view all the answers

<p>Proper management in composting facilities. (C)</p> Signup and view all the answers

<p>By microbial fermentation of sugars. (D)</p> Signup and view all the answers

<p>High production costs. (A), Long decomposition times. (D)</p> Signup and view all the answers

<p>It does not show a variation in color. (D)</p> Signup and view all the answers

<p>They are simple molecules that combine to form polymers. (D)</p> Signup and view all the answers

<p>Polymers form through a process called polymerization. (A)</p> Signup and view all the answers

<p>Hermann Staudinger (D)</p> Signup and view all the answers

<p>10,000 to 100,000 (C)</p> Signup and view all the answers

<p>Vinyl chloride (B)</p> Signup and view all the answers

<p>They provide essential materials like food, shelter, and clothing. (C)</p> Signup and view all the answers

<p>Cellulose (A)</p> Signup and view all the answers

<p>1, 4-β-D-glycosidic linkages (B)</p> Signup and view all the answers

<p>Through a chemical process called polymerization (B)</p> Signup and view all the answers

<p>Amorphous structure (B)</p> Signup and view all the answers

<p>Monomers (C)</p> Signup and view all the answers

<p>Composition of branched polymers (B)</p> Signup and view all the answers

<p>Hemicelluloses have a lower molecular weight (A)</p> Signup and view all the answers

<p>50-300 (B)</p> Signup and view all the answers

<p>They form a protective matrix for cellulose (C)</p> Signup and view all the answers

<p>A mixture of 5-carbon and 6-carbon rings (C)</p> Signup and view all the answers

<p>It leads to the relaxation of the crystalline structure. (B)</p> Signup and view all the answers

<p>By reducing hydrophilic hydroxyl groups. (D)</p> Signup and view all the answers

<p>Cleaner and rougher fibre surface. (D)</p> Signup and view all the answers

<p>It decreases. (D)</p> Signup and view all the answers

<p>They react with lignin constituents. (C)</p> Signup and view all the answers

<p>Enhanced adhesion with the polymer matrix. (A)</p> Signup and view all the answers

<p>Some hemicelluloses and lignin. (C)</p> Signup and view all the answers

<p>Reactive hydrogen bonds are formed. (B)</p> Signup and view all the answers

<p>To expose more reactive groups on the fibre surface (D)</p> Signup and view all the answers

<p>It decreases (A)</p> Signup and view all the answers

<p>It allows for better adhesion with polymer matrix (B)</p> Signup and view all the answers

<p>Enhanced color vibrancy (C)</p> Signup and view all the answers

<p>1940 (B)</p> Signup and view all the answers

<p>Any material made of by more than one component (A)</p> Signup and view all the answers

<p>They have gained popularity in the construction sector (D)</p> Signup and view all the answers

<p>Concrete (B)</p> Signup and view all the answers

A large molecule formed by many small repeating units (monomers).

A simple molecule that can bond to form a polymer chain.

The process of converting monomers into polymers.

A chemist who proposed the existence of macromolecules and won the Nobel Prize in 1953.

A large molecule made up of many atoms, often formed from polymerization of monomers.

Strong bonds formed by the sharing of electrons between atoms in a polymer.

Common polymers include PE, PP, PVC, and Teflon, each with unique properties.

Monomers are the basic units from which polymers are constructed.

Alkali treatment causes cellulose swelling, enhancing chemical penetration.

Non-crystalline cellulose formed when alkali disrupts structure.

Changes in hydrogen bonds reduce moisture resistance of natural fibers.

Alkali treatment makes fiber surfaces cleaner and rougher.

Alkali treatment removes hemicelluloses, cleaning fiber surfaces.

Fibers treated with KMnO4 react to further enhance surface texture.

Roughened fiber surface from treatment improves adhesion to the polymer matrix.

Reduces fiber diameter, improving fiber-matrix adhesion.

Polymers that can degrade by decomposers, such as natural rubber.

Polymers that are non-biodegradable and man-made.

Also known as PMMA, a transparent thermoplastic from methyl methacrylate.

Transparent, softens at 120°C, resistant to solvents, allows UV rays.

Used in unbreakable windows, camera lenses, and safety glasses.

Polymers with urethane linkages, produced from diisocyanates and glycols.

Available as elastomers, foams, and resistant to oil and chemicals.

Foams that are either rigid or flexible and highly stretchable.

Fibres derived from plants or animals containing cellulose, hemicellulose, lignin, and others.

A linear polymer crucial for strength and stability in natural fibres, made of D-anhydro glucose units.

Bonds that connect glucose units in cellulose, contributing to its structure.

The number of repeating units in a polymer; higher means stronger properties.

Amorphous, branched polymers with lower molecular weight than cellulose, aiding in fibre structure.

A complex organic polymer in plant cell walls providing rigidity and resistance to decay.

A polysaccharide found in plant cell walls that helps bind cells together.

Includes cellulose, hemicelluloses, lignin, pectin, and waxes that define properties of fibres.

A chemically modified form of polyaniline that enhances its conductivity.

Polyaniline exhibits different colors based on its protonation and oxidation states.

Used in lithography, electromagnetic control, biosensors, and rechargeable batteries.

Derived from renewable resources like plants or produced by bacteria.

Biodegradable polymers are most effective in proper composting environments.

Selecting the right type is crucial for effectiveness in different applications.

Polyaniline's properties can be utilized in smart windows that manage solar energy.

A process using acrylic acid on pre-treated natural fibres.

An initial cleaning step to enhance fibre reactivity.

Active sites in cellulose that facilitate polymerization.

A bond formed between carboxylic acid and alcohol groups.

Ability of fibres to absorb water, reduced by treatment.

Materials made from two or more components, often including polymers.

Used in construction, aerospace, and military for durability.

Composites formed from two types of polymers, like feathers or wood.