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The document discusses environmental degradation of polymers. It defines monomers as small molecules used to synthesize polymers through chemical bonding. Polymer degradation is a change in properties like strength, color or shape due to environmental factors like heat, light or chemicals. There are various types of degradation including thermal, photo-oxidative, mechanical, biological and through irradiation or chemicals. Reducing eliminated byproducts like HCl from thermal degradation of PVC can help reduce degradation, as can using polymers with strong chemical bonds.
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Polymer
The document discusses the degradation of polymers. It defines polymer degradation as a change in properties like tensile strength and shape due to environmental factors like heat, light, or chemicals. The types of degradation discussed are photo induced, thermal, chemical, biological, and mechanical. The effects of degradation are reduced ductility, embrittlement, color changes, cracking, and changes to molecular structure. In conclusion, polymer degradation is often due to changes in the chemical and physical structure of polymer chains.
Polymers
This document discusses various types and causes of polymer degradation, including chemical, thermal, oxidative, hydrolytic, mechanical, photochemical, radiation, biological, and corrosion-related degradation. It also describes methods of protecting polymers from degradation, such as adding stabilizers like antioxidants, light stabilizers, radical scavengers, metal deactivators, and bio-stabilizers.
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This document discusses recent advancements in dental polymers and base techniques. It begins with definitions of polymers and polymerization. The history of dental polymers is then reviewed, including the development of synthetic elastomers in the 20th century and the introduction of PMMA and resin-based composites. Various dental applications of polymers are listed. Key aspects of polymers like chain length, branching, copolymer structures, and properties are described. The document concludes with an overview of addition and step-growth polymerization, as well as details on acrylic dental resins.
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The document discusses various processes involved in the production of ethylene and polymers from petroleum sources and biomass. It describes how ethylene is produced through thermal and catalytic cracking of petroleum fractions. Ethylene is a monomer that undergoes polymerization to form polyethylene. It also discusses how cellulose from biomass can potentially be used as a raw material to produce petrochemicals like ethylene.
Polymer notes.pptx
Polymers are large molecules formed by combining many smaller subunits called monomers. They can be found naturally or made synthetically. Polymers are formed through polymerization reactions where monomers bond together into long chains or networks. There are several ways polymers can be classified, including by their source, structure, type of polymerization reaction, monomers used, intermolecular forces, backbone composition, and atomic arrangement. The functionality and degree of polymerization also provide information about polymers' structure and properties.
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Polymer
The document discusses the degradation of polymers. It defines polymer degradation as a change in properties like tensile strength and shape due to environmental factors like heat, light, or chemicals. The types of degradation discussed are photo induced, thermal, chemical, biological, and mechanical. The effects of degradation are reduced ductility, embrittlement, color changes, cracking, and changes to molecular structure. In conclusion, polymer degradation is often due to changes in the chemical and physical structure of polymer chains.
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This document discusses various types and causes of polymer degradation, including chemical, thermal, oxidative, hydrolytic, mechanical, photochemical, radiation, biological, and corrosion-related degradation. It also describes methods of protecting polymers from degradation, such as adding stabilizers like antioxidants, light stabilizers, radical scavengers, metal deactivators, and bio-stabilizers.
engineering chemistry power point presentation
in this there is description of Course Outcome- fuels & combustion and Polymers etc.
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Polymer is a heart of controlled drug delivery system. Application of polymers are increasing in pharmaceuticals these days .
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This document discusses recent advancements in dental polymers and base techniques. It begins with definitions of polymers and polymerization. The history of dental polymers is then reviewed, including the development of synthetic elastomers in the 20th century and the introduction of PMMA and resin-based composites. Various dental applications of polymers are listed. Key aspects of polymers like chain length, branching, copolymer structures, and properties are described. The document concludes with an overview of addition and step-growth polymerization, as well as details on acrylic dental resins.
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Polymer notes.pptx
Polymers are large molecules formed by combining many smaller subunits called monomers. They can be found naturally or made synthetically. Polymers are formed through polymerization reactions where monomers bond together into long chains or networks. There are several ways polymers can be classified, including by their source, structure, type of polymerization reaction, monomers used, intermolecular forces, backbone composition, and atomic arrangement. The functionality and degree of polymerization also provide information about polymers' structure and properties.
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Methods of polymerisation It is also called as Zeigler – Natta polymerisation.
Zeigler (1953) and Natta (1955) discovered that in the presence of a combination of transition metal halides like TCl4, ZnBr3 etc, with an organometallic compound like triethyl-aluminium or trimethyl-aluminium, stereospecific polymerisation can be carried out.
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Plastics are polymers composed of large organic molecules called polymers and additives that give them their properties. Polymers are formed from bonding monomers together in long chains through polymerization. Plastics are generally light, good insulators, resistant to corrosion, and mouldable but have low melting points and degrade under UV light. There are three main types of plastics: thermoplastics which have weaker bonds and can be recycled; thermosets which have stronger bonds and cannot be recycled; and elastomers which are very flexible and also cannot be recycled. Plastics are manufactured by heating polymer particles to their melting point and shaping them through extrusion or injection molding.
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polymers-chapter, classifications, metho
Polymers are large molecules composed of repeating structural units and can be classified based on source, structure, polymerization method, or molecular forces. They are used widely in pharmaceutical applications such as controlled drug delivery systems due to their ability to control drug release through diffusion, degradation, or swelling. Common polymers used include PLGA, PLA, cellulose derivatives, and polyacrylates. They are applied in oral, transdermal, and ocular drug delivery systems to control and sustain drug release.
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Polymers are large molecules composed of repeating structural units and can be classified based on source, structure, polymerization method, or molecular forces. They are used widely in pharmaceutical applications such as controlled drug delivery systems due to their ability to control drug release through diffusion, degradation, or swelling. Common polymers used include PLGA, PLA, and chitosan and they can be applied in oral, transdermal, and ocular drug delivery systems.
Engineering Chemistry - POLYMERS - 20.ppt
Polymers are macro molecules formed by linking smaller molecules called monomers repeatedly. Polymers can be classified in several ways, including by origin (natural vs synthetic), structure (linear, branched, cross-linked), method of formation (addition vs condensation), response to heat (thermosetting vs thermoplastic), and properties/applications (plastics, elastomers, fibers, resins). Key properties of polymers like tensile strength, plastic deformation, chemical resistance, and crystallinity depend on factors like intermolecular forces, molecular shape and arrangement, and chemical composition.
The Environmental Behaviour Of Polymers
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Polymers are giant molecules composed of repeating structural units joined together. They can be classified based on their origin (natural, semi-synthetic, synthetic), thermal response (thermoplastic, thermosetting), structure (linear, branched, cross-linked), and application (rubber, plastic, fibers). Polymerization is the process of linking monomers together to form polymers. It occurs via two main mechanisms: step-growth polymerization (condensation polymerization) and chain-growth polymerization (addition polymerization). Step-growth involves the elimination of a small molecule as monomers react together in a step-wise manner, while chain-growth is a chain reaction with no byproducts as monomers continuously add to the
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Polymer science deals with large macromolecules made of repeating monomer units. Polymers can be classified in several ways, including by their origin (synthetic, biopolymer, etc.), monomer composition (homopolymer, copolymer like statistical, alternating, block, and graft), chain structure (linear, branched, cross-linked, network), and thermal behavior (thermoplastics and thermosets). Polymerization can occur through step-growth or chain-growth mechanisms. Polymers degrade through various means including chemical, biological, mechanical, chlorine-induced, thermal, and photo degradation which can impact properties like strength, color, and shape over time.
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This document provides an overview of polymers, including:
- Polymers are large molecules made by linking repeating units called monomers. Naturally occurring polymers have been used for thousands of years, while artificial polymers were developed more recently after WWII.
- Polymers can be classified based on their source, thermal behavior, chemical structure, stereochemistry, and end use. Important types include thermoplastics, thermosets, homopolymers, copolymers, fibers, and plastics.
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Polymers play a very important role in human life. Our body is made of lot of polymers, e.g. Proteins, enzymes, etc. Other naturally occurring polymers like wood, rubber, leather and silk are have wide application. Now a day synthetic polymer like useful plastics, rubbers and fiber materials are synthesized. presentation includes introduction classification and preparation methods. Polymers play a very important role in human life. Our body is made of lot of polymers, e.g. Proteins, enzymes, etc. Other naturally occurring polymers like wood, rubber, leather and silk are have wide application. Now a day synthetic polymer like useful plastics, rubbers and fiber materials are synthesized. Leo Baekeland patented the first totally synthetic polymer called Bakelite (1910). Bakelite is a versatile, durable material prepared from low-cost materials phenol and formaldehyde and was the most important synthetic polymer material. In the 1920s Hermann Staudinger showed that polymers were high-molecular-weight compounds held together by normal covalent bonds.
The suffix in polymer ‘mer’ is originated from Greek word meros – which means part. The word polymer is thus coined to mean material consisting of many parts or mers. A macromolecule having high molecular mass (103-107u) and generally not a well-defined structure or molecular weight. The macromolecules formed by joining of repeating structural units on a large scale. The repeating structural units are simple and reactive molecules linked to each other by covalent bonds. This process of formation of polymers from respective monomers is called polymerization. Most of the polymers are basically organic compounds, however they can be inorganic (e.g. silicones based on Si-O network).
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This document provides an overview of polymers including their classification, characteristics, and applications. It discusses how polymers are large molecules formed from monomers linking together in chains. Polymers can be classified based on their source, structure, polymerization method, or molecular forces. They have properties like low density, moldability, and corrosion resistance. Important applications of polymers discussed are for oral, transdermal, and ocular drug delivery systems where they can control and sustain drug release through diffusion, degradation, or swelling mechanisms.
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Polymers are large molecules formed by linking together many small molecules called monomers. They can be natural, semi-synthetic, or synthetic. Polymers are classified based on their source, thermal response, mode of formation, structure, tacticity, and application. Common pharmaceutical applications of polymers include use as binders, coatings, and for controlled drug release. Properties like film-forming, thickening, and gelling make polymers useful for various drug delivery applications like tablets, liquids, and controlled release systems. Common polymers used include cellulose derivatives, hydrocolloids, poly(acrylic acid), poly(ethylene glycol), and biodegradable polymers.
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Condensation polymerization has a lower degree of polymerization and molecular weight increases slowly as functional groups are consumed in each step. In contrast, addition polymerization can achieve very high degrees of polymerization and molecular weight increases rapidly through successive monomer additions to growing chains.
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This document summarizes a seminar on polymer science. It introduces polymers, describing them as large molecules composed of repeating structural units bonded together. It then discusses different types of polymer linkages such as linear, branched, and cross-linked polymers. The document also classifies polymers according to their properties into natural/synthetic, organic/inorganic, and thermoplastic/thermosetting polymers. Finally, it covers molecular weight determination and biodegradable polymers.
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Thermal degradation of polymers occurs when polymers are exposed to high temperatures, breaking their molecular chains. This causes changes in properties like ductility, embrittlement, and color. Degradation happens through initiation, propagation, and termination reactions that produce free radicals. Methods include depolymerization, random chain scission, and side group elimination. Thermal degradation is studied using thermogravimetric analysis and differential scanning calorimetry. Stabilizers and controlling the environment can protect polymers from thermal breakdown.
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Methods of polymerisation
Methods of polymerisation It is also called as Zeigler – Natta polymerisation.
Zeigler (1953) and Natta (1955) discovered that in the presence of a combination of transition metal halides like TCl4, ZnBr3 etc, with an organometallic compound like triethyl-aluminium or trimethyl-aluminium, stereospecific polymerisation can be carried out.
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Plastics are polymers composed of large organic molecules called polymers and additives that give them their properties. Polymers are formed from bonding monomers together in long chains through polymerization. Plastics are generally light, good insulators, resistant to corrosion, and mouldable but have low melting points and degrade under UV light. There are three main types of plastics: thermoplastics which have weaker bonds and can be recycled; thermosets which have stronger bonds and cannot be recycled; and elastomers which are very flexible and also cannot be recycled. Plastics are manufactured by heating polymer particles to their melting point and shaping them through extrusion or injection molding.
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This document discusses biodegradable polymers. It begins by defining biodegradation and biodegradable polymers as polymers that break down through natural biological processes like bacterial action. It notes that biodegradable polymers are needed as an alternative to traditional polymers which account for large amounts of non-biodegradable waste. The document then discusses the structure, history, types and degradation properties of biodegradable polymers. It outlines some examples of biodegradable polymers including agro-polymers derived from biomass and biopolyesters derived from microorganisms or synthesized from natural or synthetic monomers.
polymers-chapter, classifications, metho
Polymers are large molecules composed of repeating structural units and can be classified based on source, structure, polymerization method, or molecular forces. They are used widely in pharmaceutical applications such as controlled drug delivery systems due to their ability to control drug release through diffusion, degradation, or swelling. Common polymers used include PLGA, PLA, cellulose derivatives, and polyacrylates. They are applied in oral, transdermal, and ocular drug delivery systems to control and sustain drug release.
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INTRODUCTION
CLASSIFICATION AND CHARACTERISTICS OF POLYMERS
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(2) ppt -----polymers-final-3-161225131244.pdf
Polymers are large molecules composed of repeating structural units and can be classified based on source, structure, polymerization method, or molecular forces. They are used widely in pharmaceutical applications such as controlled drug delivery systems due to their ability to control drug release through diffusion, degradation, or swelling. Common polymers used include PLGA, PLA, and chitosan and they can be applied in oral, transdermal, and ocular drug delivery systems.
Engineering Chemistry - POLYMERS - 20.ppt
Polymers are macro molecules formed by linking smaller molecules called monomers repeatedly. Polymers can be classified in several ways, including by origin (natural vs synthetic), structure (linear, branched, cross-linked), method of formation (addition vs condensation), response to heat (thermosetting vs thermoplastic), and properties/applications (plastics, elastomers, fibers, resins). Key properties of polymers like tensile strength, plastic deformation, chemical resistance, and crystallinity depend on factors like intermolecular forces, molecular shape and arrangement, and chemical composition.
The Environmental Behaviour Of Polymers
Degradation refers to changes in a polymer's properties due to environmental factors like heat, light, and chemicals. Degradation can be undesirable through cracking or chemical breakdown, but it can also be desirable through controlled biodegradation for recycling. The three main types of degradation are photodegradation from light, thermal degradation at high temperatures, and chemical degradation through hydrolysis. Anti-degradants like waxes protect polymers by preventing contact with oxygen. Environmental degradation depletes resources and destroys habitats, while environmental stress cracking causes unexpected brittle failure in plastics exposed to liquids. A polymer's structure, branching, cross-linking, and functional groups affect its reactivity and properties.
Polymers
This document discusses polymers used in pharmaceutical applications. It defines polymers as large molecular compounds formed by linking monomers. Polymers have advantages like localized drug delivery and sustained release. They are classified based on source, molecular forces, solubility, polymerization technique, and degradability. Common mechanisms of drug release from polymers include diffusion, dissolution, swelling, and erosion. Polymers find applications as coating materials, binders, suspending agents, and for sustained and delayed drug release in oral and other drug delivery applications.
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The document discusses various types of plastics including their properties, production methods, and applications. It describes key terms like polymers, monomers, and polymerization. Specific plastics covered include polyethylene, polyvinyl chloride, teflon, and epoxy resin. Their characteristics such as chemical resistance, strength, and uses in products are summarized for each plastic. The document provides an overview of important concepts relating to plastics.
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Polymers are giant molecules composed of repeating structural units joined together. They can be classified based on their origin (natural, semi-synthetic, synthetic), thermal response (thermoplastic, thermosetting), structure (linear, branched, cross-linked), and application (rubber, plastic, fibers). Polymerization is the process of linking monomers together to form polymers. It occurs via two main mechanisms: step-growth polymerization (condensation polymerization) and chain-growth polymerization (addition polymerization). Step-growth involves the elimination of a small molecule as monomers react together in a step-wise manner, while chain-growth is a chain reaction with no byproducts as monomers continuously add to the
Polymers evs ppt (3)
Polymer science deals with large macromolecules made of repeating monomer units. Polymers can be classified in several ways, including by their origin (synthetic, biopolymer, etc.), monomer composition (homopolymer, copolymer like statistical, alternating, block, and graft), chain structure (linear, branched, cross-linked, network), and thermal behavior (thermoplastics and thermosets). Polymerization can occur through step-growth or chain-growth mechanisms. Polymers degrade through various means including chemical, biological, mechanical, chlorine-induced, thermal, and photo degradation which can impact properties like strength, color, and shape over time.
Polymers
This document provides an overview of polymers, including:
- Polymers are large molecules made by linking repeating units called monomers. Naturally occurring polymers have been used for thousands of years, while artificial polymers were developed more recently after WWII.
- Polymers can be classified based on their source, thermal behavior, chemical structure, stereochemistry, and end use. Important types include thermoplastics, thermosets, homopolymers, copolymers, fibers, and plastics.
- Polymer properties depend on factors like strength, crystallinity, elasticity, and glass transition temperature which are influenced by the polymer structure. Common characterization techniques and molding processes like injection molding are also discussed.
Polymer chemistry
Polymers play a very important role in human life. Our body is made of lot of polymers, e.g. Proteins, enzymes, etc. Other naturally occurring polymers like wood, rubber, leather and silk are have wide application. Now a day synthetic polymer like useful plastics, rubbers and fiber materials are synthesized. presentation includes introduction classification and preparation methods. Polymers play a very important role in human life. Our body is made of lot of polymers, e.g. Proteins, enzymes, etc. Other naturally occurring polymers like wood, rubber, leather and silk are have wide application. Now a day synthetic polymer like useful plastics, rubbers and fiber materials are synthesized. Leo Baekeland patented the first totally synthetic polymer called Bakelite (1910). Bakelite is a versatile, durable material prepared from low-cost materials phenol and formaldehyde and was the most important synthetic polymer material. In the 1920s Hermann Staudinger showed that polymers were high-molecular-weight compounds held together by normal covalent bonds.
The suffix in polymer ‘mer’ is originated from Greek word meros – which means part. The word polymer is thus coined to mean material consisting of many parts or mers. A macromolecule having high molecular mass (103-107u) and generally not a well-defined structure or molecular weight. The macromolecules formed by joining of repeating structural units on a large scale. The repeating structural units are simple and reactive molecules linked to each other by covalent bonds. This process of formation of polymers from respective monomers is called polymerization. Most of the polymers are basically organic compounds, however they can be inorganic (e.g. silicones based on Si-O network).
Dental polymer part 1
All details about the dental polymer
Components and Composition
Molecular Weight
Polydispersity
Structure Of Polymer
Mechanical And Physical Properties Of Polymer,
Rheometric Properties
Solvation and dissolution Properties
Thermal Properties
Requirement Of Dental Resins
Dental Use Of Resins
Polymer
This document provides an overview of polymers including their classification, characteristics, and applications. It discusses how polymers are large molecules formed from monomers linking together in chains. Polymers can be classified based on their source, structure, polymerization method, or molecular forces. They have properties like low density, moldability, and corrosion resistance. Important applications of polymers discussed are for oral, transdermal, and ocular drug delivery systems where they can control and sustain drug release through diffusion, degradation, or swelling mechanisms.
PPT ON POLYMERS.pptx
Polymers are large molecules formed by linking together many small molecules called monomers. They can be natural, semi-synthetic, or synthetic. Polymers are classified based on their source, thermal response, mode of formation, structure, tacticity, and application. Common pharmaceutical applications of polymers include use as binders, coatings, and for controlled drug release. Properties like film-forming, thickening, and gelling make polymers useful for various drug delivery applications like tablets, liquids, and controlled release systems. Common polymers used include cellulose derivatives, hydrocolloids, poly(acrylic acid), poly(ethylene glycol), and biodegradable polymers.
Polymer Chemistry
Polymerization is a process of reacting monomer molecules together to form polymer chains. There are two main types of polymerization:
1) Addition (chain) polymerization involves linking monomers together through double or triple bonds. It includes initiation, propagation, and termination steps.
2) Condensation (step-growth) polymerization combines monomers by removing a small molecule, like in polyester formation. It does not involve chain growth.
Condensation polymerization has a lower degree of polymerization and molecular weight increases slowly as functional groups are consumed in each step. In contrast, addition polymerization can achieve very high degrees of polymerization and molecular weight increases rapidly through successive monomer additions to growing chains.
Polymer
This document summarizes a seminar on polymer science. It introduces polymers, describing them as large molecules composed of repeating structural units bonded together. It then discusses different types of polymer linkages such as linear, branched, and cross-linked polymers. The document also classifies polymers according to their properties into natural/synthetic, organic/inorganic, and thermoplastic/thermosetting polymers. Finally, it covers molecular weight determination and biodegradable polymers.
Thermal degradation of Polymers
Thermal degradation of polymers occurs when polymers are exposed to high temperatures, breaking their molecular chains. This causes changes in properties like ductility, embrittlement, and color. Degradation happens through initiation, propagation, and termination reactions that produce free radicals. Methods include depolymerization, random chain scission, and side group elimination. Thermal degradation is studied using thermogravimetric analysis and differential scanning calorimetry. Stabilizers and controlling the environment can protect polymers from thermal breakdown.
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Plasma expansion in the dipole magnetic field.
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bordetella pertussis.................................ppt
Bordettela is a gram negative cocobacilli spread by air born drop let
Phenomics assisted breeding in crop improvement
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
ANAMOLOUS SECONDARY GROWTH IN DICOT ROOTS.pptx
Abnormal or anomalous secondary growth in plants. It defines secondary growth as an increase in plant girth due to vascular cambium or cork cambium. Anomalous secondary growth does not follow the normal pattern of a single vascular cambium producing xylem internally and phloem externally.
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Isolation of pure culture, its various method.
Leaf Initiation, Growth and Differentiation.pdf
Leaf initiation, growth and differentiation, genetic control of leaf development.
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Presentation (1).pptx
- 2. Polymer and monomer Monomer: The term monomer refers to the small molecule from which a polymer is synthesized. Polymer: Polymer is defined chemical bonding of a monomer to produce a huge structure. Each molecule of an organic substance is considered as monomer and combination of such monomers to produce a huge structure is known as polymer.
- 5. Polymer degradation • Polymer degradation is a change in the properties of the polymer, such tensile strength, color, shape, and molecular weight, or of a polymer-based product under the influence of one or more environmental factors, such as heat, light, chemicals, or any other applied force
- 6. Types of polymer degradation • Various types of polymer degradation method including thermal, photo oxidative, mechanical, biological, by irradiation and chemical have been used traditionally
- 7. How to fix polymer degradation • In the thermal degradation process of PVC, HCl molecules are eliminated. This eliminated HCl also increases the degradation process. By removing HCl, degradation can be reduced. Polymers with high bond strength are resistant to degradation
- 8. THANK YOU