Polymers
Overzicht
Polymers are the materials that quietly shape modern life: the casing of your phone, the bottle your water comes in, the insulation around every cable in your home. The word itself tells the story - a polymer is built from many (poly) repeating units (mers) joined into long molecular chains. How those chains are arranged, and whether they can be re-melted or are locked permanently, decides everything about how a polymer behaves and how a designer can work with it.
This note covers the 0445 Materials-option polymer objectives in depth: how polymers are classified, the stock forms they are bought in, their key properties and environmental impact, the named thermoplastics from nylon and HDPE through to PLA, the two thermosetting resins you must know, and the growing family of biopolymers. Concrete product examples run throughout so you can justify a material choice, not just name one.
Doelstellingen
- demonstrate knowledge of polymers, including biopolymers, and understand their classification, stock forms, properties, environmental impact and uses
- demonstrate knowledge of thermo polymers, for example: - nylon - low- and high-density polyethylene (LDPE and HDPE) - polyethylene terephthalate (PET) - polyvinyl chloride (PVC) - acrylic (PMMA) - polystyrene (PS) - polypropylene (PP) - acrylonitrile-butadiene-styrene (ABS) - polylactic acid (PLA)
- demonstrate working knowledge of the following thermosetting polymers: - polyester resin - epoxy resin.
Lesnotitie
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Lesevaluatie
Gefeliciteerd met het voltooien van de les op Polymers. Nu je de sleutelconcepten en ideeën, het is tijd om uw kennis op de proef te stellen. Deze sectie biedt een verscheidenheid aan oefeningen vragen die bedoeld zijn om uw begrip te vergroten en u te helpen uw begrip van de stof te peilen.
Je zult een mix van vraagtypen tegenkomen, waaronder meerkeuzevragen, korte antwoordvragen en essayvragen. Elke vraag is zorgvuldig samengesteld om verschillende aspecten van je kennis en kritisch denkvermogen te beoordelen.
Gebruik dit evaluatiegedeelte als een kans om je begrip van het onderwerp te versterken en om gebieden te identificeren waar je mogelijk extra studie nodig hebt. Laat je niet ontmoedigen door eventuele uitdagingen die je tegenkomt; beschouw ze in plaats daarvan als kansen voor groei en verbetering.
- Which statement about thermosetting polymers is correct? A. They soften every time they are heated B. They can be re-melted and recycled repeatedly C. They cure permanently and cannot be reshaped by heating D. They are always made from renewable plant sources Answer: C
- Which polymer is best suited to a transparent, weather-resistant sign that must be polished to a clear finish? A. Acrylic (PMMA) B. Low-density polyethylene (LDPE) C. Nylon D. Polypropylene (PP) Answer: A
- LDPE is softer and more flexible than HDPE mainly because: A. LDPE is a thermoset and HDPE is a thermoplastic B. LDPE chains are branched and pack less tightly than HDPE chains C. LDPE contains a plasticiser and HDPE does not D. HDPE is made from plants and LDPE from oil Answer: B
- Which property makes nylon a good choice for small gears and bearings? A. It is optically transparent B. It is biodegradable C. It is tough, hard-wearing and self-lubricating with low friction D. It melts at a very low temperature Answer: C
- Which statement about PLA is correct? A. It is an oil-based thermoset B. It is bio-based and biodegradable but composts best in industrial conditions C. It cannot be used in 3D printing D. It is the toughest polymer in the syllabus Answer: B
Beschikbaar in de Green Bridge-app
Download de Green Bridge CBT-app op je telefoon of computer voor toegang tot volledige lesnotities, oefenvragen en meer.
Beschikbaar in de Green Bridge-app
Download de Green Bridge CBT-app op je telefoon of computer voor toegang tot volledige lesnotities, oefenvragen en meer.
Aanbevolen Boeken
Oefen Proefexamenvragen
Wilt u proefexamenvragen over Polymers oefenen? Download de Green Bridge CBT-app voor toegang tot proefexamenvragen en volledige oefentoetsen over dit onderwerp.
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