What factors affect polymer properties? Polymer properties depend on the chemicals that the polymer is made from and polymerization conditions that ultimately set molecular architecture: chemical linkage type, chain length, and the nature of the end groups . The type of the monomer-repeat unit that forms a polymer has a strong effect on polymer properties.
What are the factors of polymers?
The factors that influence polymer reactions include amorphous or crystal- line content, orientation, solubility, and compatibility .
Which factors decide the properties of polymer during polymerisation?
Polymerisation conditions such as chain length, type of bonds present between polymers, and nature of the functional group present at the end of the monomers . The type of monomer units polymerised to form the repeating units in polymers is one of the critical factors that decide the properties of polymers.
What are 3 properties of polymers?
- Heat capacity/ Heat conductivity. The extent to which the plastic or polymer acts as an effective insulator against the flow of heat. ...
- Thermal expansion. The extent to which the polymer expands or contracts when heated or cooled. ...
- Crystallinity. ...
- Permeability. ...
- Elastic modulus. ...
- Tensile strength. ...
- Resilience. ...
- Refractive index.
Why do polymers have different properties?
Why do different polymers have different properties? Answer: They have different chemical compositions (different monomer units), different structures, different ways of being fabricated, etc.
How can the impact of polymer properties be improved?
- Copolymer modification: It is modified during the synthesis of plastic polymers. ...
- Polymer Blending: Adding impact modifier to plastic polymers to the insufficient impact resistance and dispersing them with a twin-screw extruder. ...
- Adding glass fibers to increase impact strength.
What properties are affected by the degree of polymerization explain?
Polymers with identical composition but different molecular weights may exhibit different physical properties. In general, increasing degree of polymerization correlates with higher melting temperature and higher mechanical strength .
How does the structure of a polymer affect its properties?
Because of the structure of the molecules, polymeric materials have different properties compared to other materials, like metals. Specifically, the relatively high molecular weight and long polymer chain length result in entanglement, and the lack of covalent intermolecular bonds facilitates polymer chain mobility .
What are the 5 properties of polymers?
Physical properties of polymers include molecular weight, molar volume, density, degree of polymerization, crystallinity of material , and so on.
What is polymer and its properties?
A polymer is any of a class of natural or synthetic substances composed of very large molecules, called macromolecules, which are multiples of simpler chemical units called monomers . Polymers make up many of the materials in living organisms and are the basis of many minerals and man-made materials.
What factor affects the mechanical properties of polymers and metals?
The mechanical properties of metal are generally determined by a number of factors, including grain size, heat treatment, atmospherics exposure, and temperature . Together, these attributes affect how a metal reacts to the forces it is exposed to in industrial processes.
How do you change the properties of polymers?
Overall, the main ways to change and tune the properties of a polymer include changing the length of the polymer chains, creating branched chains from linear polymer chains, crosslinking the polymer chains and adding plasticizers into the polymer .
What affects polymer crystallinity?
The size and structure of the crystals and the degree of crystallinity depend on the type and structure of the polymer, and on the growth conditions. Narrow molecular weight, linear polymer chains, and high molecular weight increase the crystallinity.
Why is that polymers have different physical properties give example?
How do polymers have different physical properties? Give examples. In polymers, monomers are bonded, by different molecular interactions . Nature of these interactions, yield polymers of varying elasticity, tensile strength, toughness, thermal stability, etc.
How do you strengthen polymers?
Adding filler materials such as fibers, platelets, and particles is a commonly employed technique for strengthening polymer materials. Fillers such as clay, silica, and carbon network materials have been extensively researched and used in polymer composites in part due to their effect on mechanical properties.
How does molecular weight affect polymer properties?
A High molecular weight increases the impact resistance of the material. The higher degree of entanglement means that in order to rupture, more polymer bonds need to be broken, this means that the polymer can absorb more energy before failing. A High molecular weight increases the chemical resistance – to a point.
Which of the following determine the properties of a polymer?
Polymer properties are strongly linked to the molecular weight and the molecular weight distribution . As an example, Figure 1 shows the effect on molecular weight on physical properties. A polymer such as polystyrene is stiff and brittle at room temperature with a degree of polymerization of 1,000.
How does degree of polymerization affect polymer properties?
The degree of polymerization has a dramatic effect on the mechanical properties of a polymer. As chain length increases, mechanical properties such as ductility, tensile strength, and hardness rise sharply and eventually level off .
How does temperature affect degree of polymerization?
The temperature affects both the rate of free radical formation and the thermody- namic properties of the polymerization system . It is shown that monodispersity can be achieved over a considerable range of temperatures provided that a particular level of initiator is used at a given temperature.
What increases the degree of polymerization?
Increasing the degree of polymerisation. The strength properties of polymers increase with the length of the chains , which is controlled by the degree of polymerisation. For example, the tensile strength of polyethylene is directly related to the chain length, which is defined by the molecular weight (MW).
How does the structure of a material affect its properties?
The properties of organic molecules depend on their structure being made of simple molecules . The atoms in an individual molecule are joined together by strong covalent bonds . The intermolecular forces between molecules are weaker.
What are the two important properties of polymers in terms of structure?
Polymers always have at least two phases namely, amorphous and crystalline . It is not its Tg, but rather its crystallinity that determines whether the material is a plastic or rubber. The crystals (hard phases) and rubbery (soft phases) make the PE behave as a plastic with toughness, and not as a rubber.
What factors determine the properties of a material?
The mechanical and physical properties of materials are determined by their chemical composition and their internal structure , like grain size or crystal structure. Mechanical properties may be greatly affected by processing due to the rearrangement of the internal structure.
What are the factors that affect the material strength?
Volume, modulus of elasticity, distribution of forces, and yield strength affect the impact strength of a material.
How do plasticizers affect polymer properties?
When incorporated into the polymer system, plasticizers can increase the free volume between the polymer chains which allows the chain segments to move and rotate more freely allowing for increased movement of polymer chains with respect to each other, consequently, decreasing the polymer Tg and melt viscosity (11,12).
What makes a polymer more rigid?
As the number of cross-links increases , the polymer becomes more rigid. The decision to classify a polymer as branched or cross-linked is based on the extent to which the side-chains on the polymer backbone link adjacent polymer chains.
What causes polymers to get longer?
Answer and Explanation: Dehydration synthesis or reactions occur when two molecules bind together and a water molecule is lost between them. The reverse of dehydration...
What affects polymer density?
The more crystalline a polymer, the more regularly aligned its chains. Increasing the degree of crystallinity increases hardness and density.
What increases crystallization in polymers?
Increase in concentration which can occur via solvent evaporation , induces interaction between molecular chains and a possible crystallization as in the crystallization from the melt. Crystallization from solution may result in the highest degree of polymer crystallinity.
What are effect of amorphous and crystallinity of the properties of polymers?
Amorphous polymers have a high gas permeability. Crystalline polymers have a low gas permeability. Unlike amorphous polymers, crystalline polymers exhibit a melting transition temperature (T m ), glass transition temperature (T g ) and crystalline order.
What are the 4 types of polymers?
- Natural polymers. Natural polymers are all those found in nature. ...
- Synthetic polymers. Synthetic or artificial polymers are manufactured in the laboratory and generally have petroleum-derived ingredients. ...
- Addition polymers. ...
- Condensing polymers. ...
- Rearrangement polymers. ...
- Biodegradable polymers.
What are the 4 types of polymers?
- Natural Polymers: They occur naturally and are found in plants and animals. ...
- Semi-synthetic Polymers: ...
- Synthetic Polymers: ...
- Linear Polymers. ...
- Branched-chain Polymers. ...
- Cross-linked Polymers. ...
- Classification Based on Polymerization. ...
- Classification Based on Monomers.
What are physical properties of polymers?
Physical properties of polymers include molecular weight, molar volume, density, degree of polymerization, crystallinity of material , and so on.
What are the two categories of polymers?
- thermosetting plastic or thermoset.
- thermoforming plastic or thermoplastic.
What are examples of polymers?
Examples of synthetic polymers include nylon, polyethylene, polyester, Teflon, and epoxy . Natural polymers occur in nature and can be extracted. They are often water-based. Examples of naturally occurring polymers are silk, wool, DNA, cellulose and proteins.
