Why does polystyrene have low density?
- Weigh the cube to get the mass.
- Measure any side of the cube.
- Volume of the cube = side^cube
- Density= Massof the cube/ Volume
- Feel good about yourself because you know the density of the cube.
Why is polystyrene good for insulation?
few of the places that you’ve probably seen polystyrene:
- Plastic cutlery
- Shipping and packing materials
- Insulation in buildings
- Food packaging
- Libraries
Is high density polyethylene harmful?
With all the advantages high-density polyethylene pipes offer, it’s hard to believe that there would be any negatives. However, there are a few. The primary disadvantage is stress cracking.
What is the difference between polystyrene and styrofoam?
Styrofoam is a derived term of polystyrene. As nouns the difference between styrofoam and polystyrene is that styrofoam is expanded polystyrene foam, such as is used in cups and packaging while polystyrene is (organic chemistry) a vinylic polymer of styrene, ch 2 chphenyl.
What is the density polystyrene?
Polystyrene Foam (EPS) Physical Data Sheet1LB PolystyreneDensity (LB/Cubic Ft.)1.02Density (LB/Cubic Ft.)3.00Thermal Conductivity (Btu-in/hr-Sq.Ft. - °F) @ 25°F / @ 40°F / @ 75°F0.18 / 0.19 / 0.21Thermal Resistance (R-Value @ 1" Thick) @ 25°F / @ 40°F / @ 75°F5.56 / 5.26 / 4.7048 more rows
What is high density Styrofoam used for?
Due to mechanical and thermal properties, main applications in which high-density foam can be used are: Upholstery & couch cushions. High-density foam roller. Insulation panels.
What are the different grades of polystyrene?
Three major types of polystyrene include polystyrene foam, regular polystyrene plastic, and polystyrene film. Amongst the different types of foam are expanded polystyrene (EPS) and extruded polystyrene (XPS).Nov 5, 2015
What is the difference between polystyrene and high impact polystyrene?
High impact polystyrene is a low cost, tough plastic material that easily undergoes thermoforming and fabrication. The key difference between polystyrene and high impact polystyrene is that polystyrene generally has comparatively low impact strength, whereas high impact polystyrene has very high impact strength.Nov 3, 2021
What is the difference between high and low density foam?
Foams with a high density will generally feel more firm, and can withstand more pressure. Conversely, low-density foams will feel softer, but cannot withstand excessive pressure or weight. When it comes to memory foam in particular, higher-density foams recover more slowly after pressure is applied to it.Mar 11, 2022
Is high density foam good for insulation?
High-Density SPF Advantages This spray foam is often an excellent choice for roofing or other exterior insulation because of its seamless, monolithic nature. High-density spray foam can also help reduce energy costs significantly over a roof's lifetime due to its thermal resistance properties.
How strong is high impact polystyrene?
High Impact Polystyrene Properties and Material OptionsUNITSHIGH IMPACT POLYSTYRENETensile strengthpsi3,500Tensile elongation at break%55Flexural moduluspsi310,000Izod impact (notched)ft-lbs/in of notch2.82 more rows
What is the difference between Styrofoam and polystyrene?
Polystyrene is a common polymer material produces from the monomer, styrene. Styrofoam is a form of polystyrene. The key difference between polystyrene and Styrofoam is that the polystyrene is a form of synthetic aromatic hydrocarbon polymer whereas the Styrofoam is a commercial brand of polystyrene.Sep 9, 2018
What is the R-value of 50mm polystyrene?
R value or 50mm polystyrene is 1.25. R value of 50mm Celotex is 2.25.Jan 2, 2014
What is the difference between GPPS and HIPS?
GPPS is brittle and has low-impact strength as well as less dimensional stability than HIPS. Unlike HIPS, GPPS comes in either a slight blue edge or water clear edge tint. GPPS has a glass-like clarity that makes it popular in transparent food packaging, and it can be easily molded into different shapes.Mar 25, 2019
What are the advantages of high impact polystyrene?
it is sturdy and durable with strong impact resistance. it is easily processed. it is easy to paint and glue. it has a relatively low cost.Mar 24, 2014
Is high impact polystyrene brittle?
Materials and methods For many applications, polystyrene (PS) is considered to be an excessively brittle type of polymer.
What is the only commercially important form of polystyrene?
The only commercially important form of polystyrene is atactic, in which the phenyl groups are randomly distributed on both sides of the polymer chain. This random positioning prevents the chains from aligning with sufficient regularity to achieve any crystallinity. The plastic has a glass transition temperature Tg of ~90 °C. Polymerization is initiated with free radicals.
What is polystyrene polymer?
Polystyrene is an addition polymer that results when styrene monomers interconnect ( polymerization ). In the polymerization, the carbon-carbon π bond of the vinyl group is broken and a new carbon-carbon σ bond is formed, attaching to the carbon of another styrene monomer to the chain.
How is styrene butadiene rubber made?
Styrene-butadiene rubber (SBR) is produced like PS-I by graft copolymerization, but with a lower styrene content. Styrene-butadiene rubber thus consists of a rubber matrix with a polystyrene phase dispersed therein. Unlike PS-I and SBC, it is not a thermoplastic, but an elastomer. Within the rubber phase, the polystyrene phase is assembled into domains. This causes physical cross-linking on a microscopic level. When the material is heated above the glass transition point, the domains disintegrate, the cross-linking is temporarily suspended and the material can be processed like a thermoplastic.
What is the name of the substance that is heated with styrol?
This eventually led to the substance receiving its present name, polystyrene.
What is tacticity in polystyrene?
In polystyrene, tacticity describes the extent to which the phenyl group is uniformly aligned (arranged at one side) in the polymer chain. Tacticity has a strong effect on the properties of the plastic. Standard polystyrene is atactic. The diastereomer where all of the phenyl groups are on the same side is called isotactic polystyrene, which is not produced commercially.
How much density is EPS?
According to the EPS-IA ICF organization, the typical density of EPS used for insulated concrete forms ( expanded polystyrene concrete) is 1.35 to 1.80 pounds per cubic foot (21.6 to 28.8 kg/m 3 ).
When was polystyrene discovered?
Polystyrene was discovered in 1839 by Eduard Simon, an apothecary from Berlin. From storax, the resin of the Oriental sweetgum tree Liquidambar orientalis, he distilled an oily substance, a monomer that he named styrol.
What is HDPE made of?
High Density Poly Ethylene (HDPE) is a thermoplastic polymer made from petroleum. As one of the most versatile plastic materials around, HDPE plastic is used in a wide variety of applications, including plastic bottles, milk jugs, shampoo bottles, bleach bottles, cutting boards, and piping.
How much weight can a 60 gram container hold?
It’s for this reason that a 60-gram HDPE container can safely carry over a gallon of liquid or roughly eight pounds of weight.
Is HDPE better than wood?
HDPE is the perfect combination of strength, cost-efficiency, and environmental friendliness. According to one report, "Nonporous surfaces like plastic or glass are easier to clean than wood and thus better in terms of food safety.
Is HDPE moldable?
Easily Meltable and Moldable. One of the primary benefits of this plastic material comes from its inherent malleability. With this in mind, HDPE in particular excels. Thanks to a high melting point, HDPE remains rigid until very high temperatures.
Is HDPE good for water?
HDPE resists mold, mildew, and rotting, making it the ideal material for underground piping used to deliver water. Long-lasting and weather-resistant, HDPE can be sterilized by boiling, making it an ideal material for food and beverage containers. Additionally, HDPE can withstand most strong mineral acids and bases and has excellent resistance to naturally occurring chemicals found in soil. Moreover, the material is virtually impervious to most common chemicals, water, solvents, acids, detergents, and cleaning fluids.
Is HDPE plastic recyclable?
Fortunately, HDPE plastic is easily recyclable, helping keep non-biodegradable waste out of landfills, while helping reduce plastic production by up to 50 percent! If you’re looking for a cost-effective, environmentally responsible material, HDPE may be the plastic for you.
What is HDPE resin?
HDPE has SPI resin ID code 2. High-density polyethylene ( HDPE) or polyethylene high-density ( PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or "polythene" when used for HDPE pipes. With a high strength-to-density ratio, HDPE is used in the production of plastic bottles, ...
What is LDPE in toys?
Toys and playground equipment. Clear plastic bags (shown) are made of LDPE; blown-film shopping bags with handles are now made of HDPE. HDPE is used to make sturdy bottles that resist oils. Transparent bottles are usually made of other plastics, such as polyethylene terephthalate. Milk jug.
Is HDPE stronger than LDPE?
Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE. The difference in strength exceeds the difference in density, giving HDPE a higher specific strength.
Does HDPE have a higher specific strength?
The difference in strength exceeds the difference in density, giving HDPE a higher specific strength. It is also harder and more opaque and can withstand somewhat higher temperatures (120 °C/248 °F for short periods). High-density polyethylene, unlike polypropylene, cannot withstand normally required autoclaving conditions.
What is high density polyethylene?
High density polyethylene is a hydrocarbon polymer that can be prepared from ethylene via a catalytic process . Some common catalysts used here include Ziegler–Natta catalysts, chromium/silica catalysts (Phillips catalyst), and metallocene catalysts. Generally, in the polymerization process, these catalysts form free radicals at the end ...
What is HDPE polymer?
High Density Polyethylene (HDPE) High density polyethylene, often abbreviated to HDPE, is a polymer whose monomer is ethylene. It is a thermoplastic with a very high strength to density ratio. HDPE is a very versatile plastic that has a wide range of applications – from pipes to storage bottles. When compared to other plastics, the melting point ...
What is recycled HDPE used for?
Recycled HDPE is used in plastic furniture, automobile parts, and rubbish cans. To summarize, high-density polyethylene owes its popularity to its low weight, high tensile strength, high impact resistance, resistance to chemicals and high temperatures, and its ability to be easily molded.
What is the chemical formula for HDPE?
It is a polymer made up of a huge number of repeating units (known as monomers), and its chemical formula can be generalized as (C 2 H 4) n . The branching in high density polyethylene is of a relatively low degree (when compared to other categories of polyethylene). The general structure of HDPE is illustrated below.
What is HDPE used for?
HDPE is used in the fuel tanks of several types of automobiles. The piping system responsible for the distribution of natural gas is generally made of this polymer due to its resistance to corrosion and other attributes. It is used in plastic lumber and wood plastic composites.
Is HDPE safe for humans?
Products made of high density polyethylene are long-lasting and easy to maintain. Food stored in HDPE containers does not get contaminated by the polymer, making it quite safe for humans. Some important attributes of this polymer are highlighted in this subsection.
Can HDPE be molded?
Moldability. HDPE retains its rigid structure until its melting point is reached. Once in the melt state, this polymer can be easily molded into any desired shape. This property makes it an ideal choice in the production of food containers, water bottles, and plastic lumber.
What is polypropylene used for?
Polypropylene (PP) is commonly used to make: Prescription bottles. Most bottle tops.
Which plastic is the most toxic?
While all seven types of plastic have a degree of toxicity, some are far more toxic than others. PVC is the most hazardous plastic and has been dubbed the “ poison plastic ” because it contains numerous toxins that it can leach throughout its entire life cycle.
What is LDPE used for?
Low-density polyethylene is commonly used to make: Plastic wrap. Sandwich bags. Bread bags. Squeezable bottles. Plastic grocery bags. Garbage bags. Food storage containers and lids.
What is the most commonly used plastic in the world?
Polyethylene terephthalate is the most commonly used plastic in the world. It’s a good gas and moisture barrier, keeping oxygen out and carbonation in, and is mainly used to package food and drinks.
What is plastic used for?
Plastic is used to create many of the products we use every single day, from the containers our food and medicine is packaged in to eyeglasses, toys, car parts, and household materials.
Is it safe to reuse HDPE?
While it is considered a safer option for food and drink products, it’s never safe to reuse HDPE plastic for food or drinks if it did not originally contain either. High-density polyethylene is commonly used to make: HDPE is the most commonly recycled plastic and can be reused. It can be recycled into:
Is PVC a good plastic?
Polyvinyl chloride is a hard plastic that is known for its long-term stability, good weathering ability, and chemical resistance. These properties make it a good choice for household products like pipes, frames, gutters, and more. PVC is known to leach toxins throughout its entire life cycle, making it one of the most poisonous plastics.
About Polystyrene
Density of Polystyrene
- Typical densities of various substances are at atmospheric pressure. Density is defined as the mass per unit volume. It is an intensive property, which is mathematically defined as mass divided by volume: ρ = m/V In words, the density (ρ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substan...
Mechanical Properties of Polystyrene
- Strength of Polystyrene
In mechanics of materials, the strength of a material is its ability to withstand an applied load without failure or plastic deformation. Strength of materials basically considers the relationship between the external loads applied to a material and the resulting deformationor change in mate… - Ultimate Tensile Strength of Polystyrene
Ultimate tensile strength of Polystyrene is 48 MPa.
Thermal Properties of Polystyrene
- Polystyrene – Melting Point
Melting point of Polystyrene is 217 °C. Note that, these points are associated with the standard atmospheric pressure. In general, melting is a phase change of a substance from the solid to the liquid phase. The melting point of a substance is the temperature at which this phase change oc… - Polystyrene – Thermal Conductivity
Thermal conductivity of Polystyrene is 0.12 W/(m·K). The heat transfer characteristics of a solid material are measured by a property called the thermal conductivity, k (or λ), measured in W/m.K. It is a measure of a substance’s ability to transfer heat through a material by conduction. Note th…
Overview
Polystyrene (PS) /ˌpɒliˈstaɪriːn/ is a synthetic aromatic hydrocarbon polymer made from the monomer known as styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to oxygen and water vapour and has a relatively low melting point. Polystyrene is one of the most widely used plastics, …
Forms produced
Polystyrene is commonly injection molded, vacuum formed, or extruded, while expanded polystyrene is either extruded or molded in a special process. Polystyrene copolymers are also produced; these contain one or more other monomers in addition to styrene. In recent years the expanded polystyrene composites with cellulose and starch have also been produced. Polystyrene i…
History
Polystyrene was discovered in 1839 by Eduard Simon, an apothecary from Berlin. From storax, the resin of the Oriental sweetgum tree Liquidambar orientalis, he distilled an oily substance, a monomer that he named styrol. Several days later, Simon found that the styrol had thickened into a jelly he dubbed styrol oxide ("Styroloxyd") because he presumed an oxidation. By 1845 Jamaican-born chemist John Buddle Blyth and German chemist August Wilhelm von Hofmann sh…
Structure
In chemical terms, polystyrene is a long chain hydrocarbon wherein alternating carbon centers are attached to phenyl groups (a derivative of benzene). Polystyrene's chemical formula is (C 8H 8) n; it contains the chemical elements carbon and hydrogen.
The material's properties are determined by short-range van der Waals attractio…
Degradation
Polystyrene is relatively chemically inert. While it is waterproof and resistant to breakdown by many acids and bases, it is easily attacked by many organic solvents (e.g. it dissolves quickly when exposed to acetone), chlorinated solvents, and aromatic hydrocarbon solvents. Because of its resilience and inertness, it is used for fabricating many objects of commerce. Like other organic compounds, polystyrene burns to give carbon dioxide and water vapor, in addition to othe…
Co-polymers
Ordinary (homopolymeric) polystyrene has an excellent property profile about transparency, surface quality and stiffness. Its range of applications is further extended by copolymerization and other modifications (blends e.g. with PC and syndiotactic polystyrene). Several copolymers are used based on styrene: The crispiness of homopolymeric polystyrene is overcome by elastomer-modified styrene-butadiene copolymers. Copolymers of styrene and acrylonitrile (SAN) are mor…
Environmental issues
Polystyrene foams are produced using blowing agents that form bubbles and expand the foam. In expanded polystyrene, these are usually hydrocarbons such as pentane, which may pose a flammability hazard in manufacturing or storage of newly manufactured material, but have relatively mild environmental impact. Extruded polystyrene is usually made with hydrofluorocarbons (HFC-134a), whi…
Safety
The American Chemistry Council, formerly known as the Chemical Manufacturers' Association, writes:
Based on scientific tests over five decades, government safety agencies have determined that polystyrene is safe for use in foodservice products. For example, polystyrene meets the stringent standards of the U.S. Food and Drug Administration and the European Commission/European Fo…