Cross-linked polyethylene is high-density polyethylene that is manufactured by adding a catalyst to the thermoplastic resin, which turns it into a thermoset. … The result is a plastic that possesses impact resistance, tensile strength and resistance to fracture that linear polyethylene can’t match.
Table of Contents
How is polyethylene cross-linked?
7.2. 1.2 Effect of cross-linking. Cross-linked polyethylene (XLPE) possesses better physical properties than general PE. Cross-linking with water is achieved by grafting PE with silane followed by hydrolysis to Si–OH groups and subsequent condensation to form Si–O–Si bonds.
What is the difference between HDPE and XLPE?
XLPE has 10-20 times the environmental stress crack resistance of HDPE. It has 10 times the molecular weight of HDPE. It has 3-5 times the impact and tensile strength of HDPE.
What is XLPE material?
Cross-linked Polyethylene, also referred to as XLPE, is a form of insulation that is created through both heat and high pressure. One method of creating XLPE insulation is by irradiating the compound. An alternative method is using peroxide to chemically cross-link the compound.
What are examples of cross-linked polymers?
Examples of cross-linked polymers include: Polyester fiberglass, polyurethanes used as coatings, adhesives, vulcanized rubber, epoxy resins and many more.
Does XLPE melt?
With the increase of temperature, the characteristic peaks shift to small degree slightly, and the area corresponding to the amorphous phase (18°–19°) increases gradually. XLPE shows no obvious crystallization peak at 130 °C, indicating that XLPE has completely melted at this temperature.
What is cross linking in polymers?
Put simply, crosslinking involves a chemical reaction between polymer chains to link them together. … Crosslinking can influence several end properties across most applications, including: Coating chemical resistance. Polymer flow properties – block and print resistance. Coating toughness.
What is cross linking agent?
Crosslinking Agents. Crosslinking is the formation of chemical links between molecular chains to form a three-dimensional network of connected. molecules. The vulcanization of rubber using elemental sulfur is an example of crosslinking, converting raw rubber from a weak plastic to a highly resilient elastomer.
Is cross linked polyethylene recyclable?
It can operate under conventional conditions, with a simple process, low cost, low investment and high efficiency advantages. XLPE recycling methods: … With solid state shear milling technology has been successfully achieved solid waste XLPE power chemical crosslinking solution and recycling.
What is highly cross linked polyethylene?
Background: Highly cross-linked polyethylene (XLPE) was developed to address the problem of wear and osteolysis associated with metal-on-conventional ultra-high molecular weight polyethylene (UHMWPE) bearing surfaces.
What is cross linked polyolefin?
Cross linked polyolefin (XLPO) is a broad category of organic materials. Polymer is produced from a simple olefinic monomer that reacts with fellow chain members to form polymeric chains. Monomers are reactive single chain molecules. This polymer chain becomes it’s own new material.
What is cross linked polyethylene foam?
Cross-linked polyethylene foam (also known as XLPE) is a closed-cell foam characterized by a compact feel and resistance to water. … Compression molding and thermoforming are common fabricating methods used when creating components, packaging and products from closed-cell cross-linked polyethylene foams.
What is PVC and XLPE?
XLPE, as explained above, is cross-linked polyethylene material. PVC stands for polyvinyl chloride insulation. The main difference between the two is that XLPE can be used for both high and low tension applications. Its structure provides great resistance to abrasion, stress, and other wear and tear.
What is the difference between XLP and XLPE?
CROSS-LINKED POLYETHYLENE(XLP) is a material which has greater resistance to environmental stress cracking, cut-through, ozone, solvents and soldering than either low or high density polyethylene. Sometimes designated as XLPE. Can be cross-linked either chemically or irradiated.
Is PVC a cross-linked polymer?
The polymer polyvinyl chloride is formed by the polymerization of polyvinyl chloride and it has a linear structure, so polyvinyl chloride is a linear polymer, not cross linked. The repeating unit or monomer of PVC is vinyl chloride.
Is Bakelite a cross-linked polymer?
Bakelite is a condensation polymer made from formaldehyde and phenol as shown below: Thus, the correct answer is option D i.e. Bakelite is a cross-linked polymer.
Is nylon 6/6 a cross-linked polymer?
Nylons 6, 66, and 11 can be radiation crosslinked, but the first two require addition of a crosslinking agent. For example, the polyfunctional monomer triallyl isocyanurate or triallyl-cyanurate can be compounded into nylon pellets. … The crosslinking additive does not affect the thermoplastic processing stage.
Is Teflon a cross-linked polymer?
PTFE is chemically stable and generally not cross-linked by chemical method.
What is cable armouring?
In electrical power distribution, armoured cable usually means steel wire armoured cable (SWA) which is a hard-wearing power cable designed for the supply of mains electricity. … Armouring is also applied to submarine communications cables.
Is LDPE cross linked?
Almost all PEX used for pipe and tubing is made from high-density polyethylene (HDPE). PEX contains cross-linked bonds in the polymer structure, changing the thermoplastic to a thermoset. … Almost all cross-linkable polyethylene compounds (XLPE) for wire and cable applications are based on LDPE.
Is HDPE the same as PEX?
Both HDPE and PEX are polyethylene (PE), but because of their different properties care should be taken to not confuse these two very different materials.
What is the function of cross linking?
– Cross linking is used to refer the process of linking one site to another site and provide a way to allow the accessing to it. – It doesn’t need to be owned by the same person as it provides the methods that have been be built on the Internet.
What is cross linking immunology?
Crosslinking is the process of chemically joining two or more molecules by a covalent bond. … Crosslinking reagents are used in a variety of techniques to assist in determining partners and domains of protein interactions, three-dimensional structures of proteins, and molecular associations in cell membranes.
What is the major purpose of cross linking in polymers?
Chemical cross-linking has been widely used to alter the physical properties of polymeric materials, the vulcanization of rubber being a prototypic example. Linking of polymer chains through chemical linkages gives a material a more rigid structure and potentially a better-defined shape.
How does cross linking affect slime?
This is called cross-linking. This cross-linking changes the properties of the polymer from a viscous liquid to a far more viscous slime. The slime contains as much as 96% water trapped between the molecules.
What are the three major forms of cross linking?
There are three different types of crosslinkers – homobifunctional, heterobifunctional, and photoreactive crosslinking reagents. How do these types of crosslinkers differ from one another and how do you know which one to use for your specific application?
What is protein cross linking?
Crosslinking is the process of chemically joining two or more molecules by a covalent bond. … on proteins or other molecules. Attachment between two groups on a single protein results in intramolecular crosslinks that stabilize the protein tertiary or quaternary structure.
Why are cross-linked polymers not recyclable?
15–20% of polymers produced. (13) Traditional recycling of cross-linked polymers via mechanical reprocessing is impractical because their structures preclude flow, even at elevated temperatures. … Developing strategies to recycle these materials without compromising their performance represents a formidable challenge.
Can PEX be recycled?
Though PEX can’t be recycled to be re-used for tubing, it can still be re-processed to be used for other purposes. Due to the fact that PEX is cross-linked polyethylene, it can’t be melted down, a process that would be required to produce new tubing.