POLYMERS Flashcards
(48 cards)
-are materials made of long, repeating chains of molecules. The materials have unique properties, depending on the type of molecules being bonded and how they are bonded. Some polymers bend and stretch, like rubber and polyester.
POLYMERS
is often used to describe plastics, which are synthetic polymers.
polymer
POLYMERS
when cooled;
when heated
if heated enough and meet the melting temp. the plastic becomes a
become brittle
become flexible
viscous fluid
Polymers can be both
thermal and electrical insulators
is evident in the kitchen with pot and pan handles made of polymers
Thermal resistance
is almost always faster in the presence of oxygen or air due to the accelerating reactions between oxygen and carbon-centered radicals released from the initial degradation products.
Polymer degradation
These interactions with oxygen result in an increased concentration of polymer alkyl radicals leading to .
higher levels of scission and cross-linked products
-denoting substances (especially synthetic resins) that become plastic on heating and harden on cooling, and are able to repeat these processes
THERMOPLASTICS
3 KINDS OF THERMOPLASTIC
POLYETHYLENE (PE), POLYPROPYLENE (PP), POLYSTYRENE
is a lightweight, durable thermoplastic with variable crystalline structure
It is one of the most widely produced plastics in the world (tens of millions of tons are produced worldwide each year).
used in applications ranging for films, tubes, plastic parts, laminates, etc. in several markets (packaging, automotive, electrical, etc.).
Polyethylene
Polyethylene chemical formula is
(C2H4)
is a tough, rigid and crystalline thermoplastic produced from propene (or propylene) monomer
Polypropylene
The chemical formula of polypropylene is
(C3H6)
is a versatile plastic used to make a wide variety of consumer products.
As a hard, solid plastic, it is often used in products that require clarity, such as food packaging and laboratory ware.
When combined with various colorants, additives or other plastics, polystyrene is used to make appliances, electronics, automobile parts, toys, gardening pots and equipment and more.
POLYSTYRENE
USES AND BENEFITS OF POLYSTYRENE
APPLIANCES , AUTOMOTIVE , FOODSERVICE , INSULATION , MEDICAL, PACKAGING
Refrigerators, air conditioners, ovens, microwaves, vacuum cleaners, blenders – these and other appliances often are made with polystyrene (solid and foam) because it is inert (doesn’t react with other materials), cost-effective and long-lasting.
APPLIANCES
Polystyrene (solid and foam) is used to make many car parts, including knobs, instrument panels, trim, energy absorbing door panels and sound dampening foam.
AUTOMOTIVE
also is widely used in child protective seats.
Foam polystyrene
Polystyrene foodservice packaging typically insulates better, keeps food fresher longer and costs less than alternatives.
FOOD SERVICE
Lightweight polystyrene foam provides excellent thermal insulation in numerous applications, such as building walls and roofing, refrigerators and freezers, and industrial cold storage facilities.
INSULATION
is inert, durable and resistant to water damage
Polystyrene insulation
Due to its clarity and ease of sterilization, polystyrene is used for a wide range of medical applications, including tissue culture trays, test tubes, petri dishes, diagnostic components, housings for test kits and medical devices
MEDICAL
Polystyrene (solid and foam) is widely used to protect consumer products. CD and DVD cases, foam packaging peanuts for shipping, food packaging, meat/poultry trays and egg cartons typically are made with polystyrene to protect against damage or spoilage.
PACKAGING
is an economical and versatile thermoplastic polymer widely used in building and construction industry to produce door and window profiles, pipes (drinking and wastewater), wire and cable insulation, medical devices, etc.
Polyvinyl Chloride (PVC or Vinyl)