Table of Contents
Polystyrene is used in insulation and in molded items such as coffee cups. Figure 25.19. 3: Polystyrene synthesis and structure.
Which polymer is used in coffee cups?
The polyethylene lining on a standard paper coffee cup retains heat, proides a barrier to liquids and maintains the cup’s structural integrity. However, the use of polyethylene limits the recyclability of the post-consumer cup.
Which of the following polymers would be suitable for the fabrication of hot coffee cups?
The maximum temperature of hot coffee is probably slightly below 100°C (212°F). Of the polymers listed, only polystyrene and polycarbonate have glass transition temperatures of 100°C or above (Table 15.2), and would be suitable for this application.
Which polymer would you use to make a container for a hot beverage?
PET has good gas barrier performance against oxygen and carbon dioxide and consequently; it is known as the best polymer for beverage and water bottles.
Which of the following classes of organic compounds has C O as the functional group?
Aldehydes and Ketones. Aldehydes and ketones are classes of organic compounds that contain a carbonyl (C=O) group.
What are PLA cups made from?
PLA plastic, or polylactic acid, is a bio-based plastic made from renewable raw materials such as corn-based resin and is environment and resource friendly.
What are bio cups made of?
BioCups, BioBowls and Chip BioCups are made from paper sourced from managed plantations and coated with Ingeo™ – a commercially compostable bioplastic made from plants, not oil.
What is the glass transition temperature?
Glass transition temperatures are very variable ranging from 140 °C to 370 °C according to the grades, curing process and the moisture content: For a defined grade, the glass transition temperature increases from 50 °C during post cure.
Is it possible to determine whether one polymer has a higher melting temperature than the other?
15.31 (a) Yes, it is possible to determine which polymer has the higher melting temperature. The linear polyethylene will most likely have a higher percent crystallinity, and, therefore, a higher melting temperature than the branched polyethylene.
What is polyamide used for?
Polyamide is common in textiles like clothing and carpets. It also often features in the production of items that require both strength and flexibility, including fishing line, electrical connectors, gears, guitar picks and strings and medical implants.
What is LDPE plastic used for?
Low density polyethylene (LDPE). This clear or translucent plastic exhibits flexibility, chemical resistance, and waterproofing capabilities. It is used in the manufacture of a wide range of products, including grocery bags, plastic wrap and film, flexible packaging material, and injection molded parts.
What are examples of thermoplastics?
Common examples of thermoplastics include acrylic, polyester, polypropylene, polystyrene, nylon and Teflon. These materials see a wide variety of use in manufacturing products from clothing and non-stick cookware to carpets and laboratory equipment.
What are PLA cups?
Eco-Products offers cups, lids, cutlery, straws and containers made from a biopolymer called PLA (polylactic acid). PLA is made from starchy plants like corn, grown right here in the U.S. Starch from corn kernels is processed into a biopolymer that looks, acts, and performs like petroleum-based plastics.
What are coffee cups lined with?
Paper cups might seem like a better option but, on its own, paper cannot hold liquid so baristas pour coffee into cups lined with polyethylene, a plastic that functions as a moisture barrier. The lining must be separated from the cup before the paper portion can be recycled, explains Rachel A.
How are PLA plastics made?
PLA is a polyester made through the fermentation under controlled conditions of a carbohydrate source like corn starch or sugarcane. This process “breaks” starch into dextrose (D-glucose), or corn sugar. Finally, fermentation of glucose produces L-Lactic acid, which will be the basic constituent of PLA.
What are bio cups?
Clear cups & lids Clear BioCups look and perform like conventional plastic cups but they are made from Ingeo™ – a bioplastic made from plants, not oil. Choose plastic-free BioCups – the only clear cups certified commercially compostable. Available in 16 different sizes.
How are bioplastics created?
Bioplastics are made by convert- ing the sugar present in plants into plas- tic. Other countries use sugar cane, sugar beets, wheat, or potatoes. This makes bioplastics renew- able and better for the environ- ment than conventional plastics. Two types of bioplastics are now produced in large quanti- ties.
What is TG and TM in polymers?
Tg (glass transition temp ) – the onset of segmental motion of the polymer backbone. The noncrystalline portion of the material exhibits a Tg . Tm (melting point ) – temp.
What is TM in polymer?
TM of polymers or TM polymers is the melting temperature. At this temperature, the crystalline phase of a polymer converts into a solid amorphous phase. Therefore, this is different from the usual melting process of other materials in which sold phase converts into liquid phase.
What is HDT plastic?
The heat deflection temperature or heat distortion temperature (HDT, HDTUL, or DTUL) is the temperature at which a polymer or plastic sample deforms under a specified load.
Why polypropylene has higher melting point than polyethylene?
Polypropylenes are light in weight. They have a high resistance to cracking, acids, organic solvents and electrolytes. Monomer of polyethylene is ethylene and monomer of polypropylene is propylene. Polyethylene has a lower melting point compared to the higher melting point of polypropylene.
What type of polymer is nylon?
14.5. Nylon is a polyamide polymer characterized by the presence of amide groups—(CO–NH)—in the main polymer chain.
Is polyamide nylon or polyester?
Polyester and polyamide are both synthetic fabrics that are made from the same types of materials. They are both textiles that are essentially made from plastic.Polyester vs Polyamide: Key Points. Polyester Polyamide Softness Sometimes stiff, not as soft Very soft and comfortable.
Is polyethylene a polyamide?
is that polyethylene is (organic compound) a polymer consisting of many ethylene monomers bonded together; used for kitchenware, containers etc while polyamide is (chemistry) any of a range of polymers containing amide (or peptide) repeat units; examples include proteins and nylon.
Is LDPE an addition polymer?
LDPE – Low Density Polyethylene: The first commercial polyethylene process used peroxide catalysts at a temperature of 500 C and 1000 atmospheres of pressure. This yields a transparent polymer with highly branched chains which do not pack together well and is low in density. LDPE is recyclable plastic #4.
What is polypropylene used for?
Polypropylene (PP) is one of the most commonly used thermoplastics in the world. Polypropylene uses range from plastic packaging, plastic parts for machinery and equipment and even fibres and textiles.
What is LDPE chemistry?
LDPE (low density polyethylene) is a soft, flexible, lightweight plastic material. LDPE has good chemical and impact resistance and is easy to fabricate and form.
