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1、PPT courseware for High Material Professional EnglOverview of Polymer MaterialsThe Chemical Basis of Polymer MaterialsThe physical properties of polymer materialsProcessing and Forming of Polymer MaterialsEnvironmental behavior of polymer materialsThe Development Trends and Prospects of Polymer Mate
2、rialscontents目录01Overview of Polymer Materials Definition of polymersSummary Polymers are long chain macromolecules formed by covalent bonding of many small molecules,usually with repetitive structural units.They can be naturally present,such as proteins and nucleic acids,or they can be synthetic,su
3、ch as plastics and synthetic fibers.Detailed descriptionDefinition of Polymer MaterialsSummary Classification of polymersDetailed description Polymers can be divided into natural polymers and synthetic polymers based on their source,structure,and properties.Natural polymers such as cellulose and pro
4、tein,while synthetic polymers such as synthetic rubber and synthetic fibers.In addition,polymers can also be classified based on their thermal,electrical,and optical properties.Classification of Polymer MaterialsSummary:Application of Polymer MaterialsDetailed description:Polymer materials have wide
5、 applications in various fields.In daily life,polymer materials are used to manufacture clothing,furniture,tableware,electronic products,etc.In industrial production,polymer materials are used to manufacture mechanical components,chemical equipment,building materials,etc.In addition,polymer material
6、s have important applications in medical,aerospace,military and other fields.Application of Polymer Materials02The Chemical Basis of Polymer MaterialsTypes of polymerization reactionsA type of polymerization reaction in which monomer molecules add to the polymer chain one at a time,using results in
7、a linear structureStep growth polymerizationA type of polymerization reaction in which monomers add to growing polymer chains without the loss of small moleculesAddition polymerizationA type of polymerization reaction in which two monomer molecules condense to form a single polymer chainCondensation
8、 polymerizationNaming and structure of polymersPolymer names are commonly derived from the name of the monomer,with the suffix-one or-one addedThe structure of polymers can vary depending on the type of polymerization reaction and the monomer usedSome common polymer structures include linear,branche
9、d,cross linked,and graded polymersPolymer modification can involve changing the chemical structure,physical properties,or surface characteristics of a polymerSome common methods of polymer modification include grading,cross linking,and blendingPolymer synthesis involves the conversion of monomers in
10、to polymers through polymerization reactionsSynthesis and Modification of Polymers03The physical properties of polymer materialsMolecular Movement Polymers have the ability to underground molecular movement due to their long chain structure This movement is essential for polymer processing and can b
11、e affected by temperature,pressure,and shear rateTransformation Polymer transformation occurs when the chains change their conformation or configuration This transformation can lead to changes in the physical properties of the polymer,such as its elasticity,toughness,and glass transition temperature
12、Molecular Movement and Transformation of Polymers Polymers exhibit elastic behavior due to their ability to recover their shape after being deformed The elastic modulus measures the stiffness of a polymer and depends on the type of bonds and the chain configuration Polymers can stand with a certain
13、amount of tension stress before breaking The tense strength and elongation at break are important mechanical properties that determine the usability of polymers in various applications Polymers can go under flexible deformation,which allows them to bend without breaking The flexible modular measures
14、 of stickiness of a polymer under bending loads and are critical in determining the durability of polymer productsElasticityTensile StrengthFlexibilityThe mechanical properties of polymers The Melting Point of a polymer is the temperature at which the chains lose their crystalline structure and begi
15、n to flow The melting point is an important parameter for processing polymers and depends on the type of bonds and the chain configuration Polymers may degrade at high temperatures due to chemical reactions between the chains The thermal stability of a polymer depends on its chemical composition and
16、 the type of bonds within the chains Polymers have low thermal conductivity compared to metals and ceramics This property makes polymers suitable for use in thermal insulation applications where heat transfer needs to be minimizedMelting PointThermal StabilityThermal conductivityThermal properties o
17、f polymers04Processing and Forming of Polymer Materials Ensure that the raw materials used are of good quality and comply with the required standardsMaterial inspection Convert the mixed materials into small pellets for easy handling and processingPelletizing Blending the raw materials according to
18、the formula to ensure uniformity and consistencyMixing Remove movement from the mixed materials to prevent movement related issues during processingDryingPreparation process before processing01020304Forming processExtensionForce the molten polymer through a die to form a specific shape or structureI
19、njection moldingFeed the molten polymer into a mold under high pressure to create complex shapes with precision dimensionsBlowing moldingForm hold shapes by inflating the polymer against a moldLaminationCombine multiple layers of polymer films using heat and pressure to create composite structuresPr
20、oblems and Solutions in ProcessingVariations in material propertiesEnsure consistent raw material quality and mixing procedures to minimize variationsProcessing differencesExperiment with different processing parameters to optimize the processing conditionsWarpage and destructionControl the cooling
21、rate and use appropriate molds to minimize Warpage and destruction during formattingSurface defectsIncrease surface smoothness by using polishing or coating techniques after processing05Environmental behavior of polymer materialsDescription of aging phenomenon Polymer materials undergo changes in ph
22、ysical and chemical properties after long-term use or exposure to specific environmental conditions,leading to a decline in their performance.Aging mechanism The aging phenomenon is mainly related to the chemical structure of polymer chains,environmental factors(such as temperature,humidity,ultravio
23、let radiation,etc.),and microscopic defects inside the polymer.The impact of aging on performance Over time,the strength,toughness,and durability of polymers may decrease,leading to materials gradually becoming brittle and brittle.The aging phenomenon of polymersMethods to improve environmental adap
24、tability:By changing the chemical structure of polymers,adding stabilizers,or performing surface treatments,the environmental adaptability of polymers can be improved.Environmental adaptability definition:refers to the ability of polymer materials to maintain their performance stability under variou
25、s environmental conditions(such as temperature,humidity,light,chemical corrosion,etc.).Influencing factors:The chemical structure,additives,microstructure,and surface properties of polymers can all affect their environmental adaptability.Environmental adaptability of polymersBiodegradability of poly
26、mers010203Biodegradability is defined as the ability of polymer materials to be decomposed into small molecules and harmless substances by microorganisms in the natural environment.The mechanism of biodegradation:Microorganisms break down the chemical bonds of polymers by secreting enzymes,ultimatel
27、y breaking them down into harmless substances such as water and carbon dioxide.Biodegradable applications:Degradable plastics can be used in fields such as disposable tableware,packaging materials,and agricultural films to reduce white pollution.06The Development Trends and Prospects of Polymer Mate
28、rialsNew polymer materials With the development of science and technology,more and more new polymer materials are emerging,such as high performance polymers,polymer composites,polymer nanocomposites,etc.,which have broad application prospects in the fields of aerospace,automobiles,electronics,and ot
29、her fieldsAdvanced processing technology With the continuous development of processing technology,more and more advanced processing methods of polymer materials have been developed,such as injection molding,extrusion molding,compression molding,etc.,which can produce polymer products with complex sh
30、apes and high performanceThe application of new materials and technologiesSustainable development of polymer materialsEnvironmental protection:Polymer materials are widely used in daily life,but also bring about a series of environmental problems In order to solve these problems,it is necessary to p
31、ay attention to the environmental protection of polymer materials in the production process,and try to reduce the pollution of polymer materials to the environmentResource saving:Polymer materials are non renewable resources,so it is necessary to pay attention to the resource saving in the productio
32、n process of polymer materials,and try to reduce the consumption of polymer materials With the development of science and technology,more and more new preparation technologies of polymer materials have been developed,such as polymerization method,crystallization method,etc.,which can prepare polymer
33、 materials with better performanceNew preparation technology With the development of science and technology,polymer materials are applied more and more widely in new fields,such as biomedicine,energy storage and conversion,etc.,which provides new application prospects for polymer materialsNew application fieldFrontier research on polymer materials感谢您的观看THANKS