Thermosetting plastics
Thermoset plastics cannot change shape because they undergo a irreversible chemical reaction during the curing process. This reaction, known as crosslinking, creates strong bonds between the polymer chains, making the material rigid and inflexible. Once set, thermoset plastics cannot be melted or reshaped like thermoplastics.
Thermoplastics plastics can be heated and then moulded into a shape or form, but thermosetting cannot. Each plastic can be moulded into a 'shape or form', it is just that thermoplastics, once they have been moulded, they can be re-heated and moulded again, where-as once thermosetting plastics have been moulded, if re-heated and you try to remould it, it will just make it brittle and snap instead.
There are two types of plastic: thermosetting and thermoplastic.Thermosetting plastics, such as Bakelite, use resins that are baked into their final form, usually in a mould. The chemical reaction of baking changes the resin so that it can no longer become fluid if reheated. These plastics cannot be "remolded", only powdered and put to other uses.Thermoplatics (the bulk of plastic materials) use resins that are not baked in their moulds. Thermoplastics are heated until they flow, then cast into shape. Because they are only heated to flow temperature, no chemical reaction of heating occurs, and they can be re-moulded in a recycling process.p.s. Bakelite is named for its inventor, Baekland, not because of its processing. True Bakelite is dark brown to black, so light-coloured "hard plastic" radio cabinets are *not* Bakelite - they are commonly Catalin, urea formaldehyde, or some other resin.
Cross-links usually occur when a polymer molecule is at a larger size. A larger sized molecule is held together by stronger covalent bonds, and henceforth the force between the molecules is stronger. As the force between the molecules gets stronger, more energy is needed to separate them, meaning the melting point increases.
Borax plays the role of a cross-linking agent in making polymer slime. It forms cross-links between the polymer chains, which helps to give the slime its unique stretchy and squishy properties.
Thermoset plastics cannot change shape because they undergo a irreversible chemical reaction during the curing process. This reaction, known as crosslinking, creates strong bonds between the polymer chains, making the material rigid and inflexible. Once set, thermoset plastics cannot be melted or reshaped like thermoplastics.
Plastics have stronger bonds between the polymer chains-thesemight be covalent bonds between the chains, or cross-linking bridges. These plastics have a higher melting point, are rigid and can't be stretched, as the cross-links hold the chains firmly together.Hope i helped :-)
covalent bonds between chains of molecules of a polymer or polymers, fastening the chains together. See also cross-linked polymer, under polymer.
Cysteine is the amino acid that can stabilize protein structures by forming covalent cross-links between polypeptide chains through disulfide bonds.
Yes,Plastics can be classified by chemical structure, namely the molecular units that make up the polymer's backbone and side chains. Some important groups in these classifications are the acrylics, polyesters, silicones, polyurethanes, and halogenated plastics. Plastics can also be classified by the chemical process used in their synthesis, such as condensation, polyaddition, and cross-linking.
Thermosoftening plastics are plastics that when heated, the polymers turn into a gooey kind of material which can then be put into a mould of whatever shape you wish the plastic to be. when it sets, you have your shaped plastic. thermosoftening plastics can be reheated and remoulded whereas thermosetting plastics cant be as the polymers for them, once moulded, cannot go gooey again because they have stronger chains between the polymers.
Thermoplastics plastics can be heated and then moulded into a shape or form, but thermosetting cannot. Each plastic can be moulded into a 'shape or form', it is just that thermoplastics, once they have been moulded, they can be re-heated and moulded again, where-as once thermosetting plastics have been moulded, if re-heated and you try to remould it, it will just make it brittle and snap instead.
two mountain chains cross Guatemala from west to east
There are two types of plastic: thermosetting and thermoplastic.Thermosetting plastics, such as Bakelite, use resins that are baked into their final form, usually in a mould. The chemical reaction of baking changes the resin so that it can no longer become fluid if reheated. These plastics cannot be "remolded", only powdered and put to other uses.Thermoplatics (the bulk of plastic materials) use resins that are not baked in their moulds. Thermoplastics are heated until they flow, then cast into shape. Because they are only heated to flow temperature, no chemical reaction of heating occurs, and they can be re-moulded in a recycling process.p.s. Bakelite is named for its inventor, Baekland, not because of its processing. True Bakelite is dark brown to black, so light-coloured "hard plastic" radio cabinets are *not* Bakelite - they are commonly Catalin, urea formaldehyde, or some other resin.
The mountains that cross Italy are the Apennine Mountains
Cross-links usually occur when a polymer molecule is at a larger size. A larger sized molecule is held together by stronger covalent bonds, and henceforth the force between the molecules is stronger. As the force between the molecules gets stronger, more energy is needed to separate them, meaning the melting point increases.
No good reason except maybe to take up some slack in the chains.