Fundamentals of Polymer Engineering Part 16 ppt

... therefore, no pressurization of melt in the screw bushings. A consequence of this is a decoupling of the different parts of the extruder, and what happens in one portion of the extruder does not ... single-screw device feeds solid polymer to the TSE at any desired rate, and as a consequence, the conveying channels of the TSE are only partially filled with polymer; the degree of...

Ngày tải lên: 10/08/2014, 19:20

... Inc. contourlengthRandthemeansquareend-to-enddistance?Letthechainhaven bondsandlettherebefreerotationaboutthebonds. Solution:FromFigure10.3,itisclearthattheprojectedlengthofeachlinkis lsinðy=2Þ.Usingthegivenvalueofyandnotingthattherearenlinks,thefully extendedchainlengthisgivenby R¼nlsinð54:75  Þ¼ ffiffiffiffi 2 3 r nl Themeansquareend-to-enddistanceisobtainedfromEq.(10.2.15)asfollows: hr 2 i¼2nl 2...

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... Inc. semicrystallineandtheotheramorphous,noncrystallizablesequenceswillbe builtinbetweenthecrystallizablesequencesofthesemicrystallinepolymer.This hasaprofoundeffectonthecrystallizationbehaviorofthesemicrystalline polymer[ 33].Inparticular,thereisareductioninthemeltingpointofthe crystalsandachangeintheglasstransitiontemperature;theT g oftheresulting randomcopolymercanbeestimatedusingEq.(9.6....

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... Inc. 6.4RecyclingandDegradationofPolymers285 6.5Conclusion287 Appendix6.1:SolutionofEquationsDescribing IsothermalRadicalPolymerization287 References293 Problems294 7.EmulsionPolymerization299 7.1Introduction299 7.2AqueousEmulsifierSolutions300 7.3SmithandEwartTheoryforStateIIofEmulsion Polymerization304 7.4EstimationoftheTotalNumberofParticles,N t 313 7.5MonomerConcentrationinPolymerParticles...

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... molecular structure of the graft copolymer and the number of grafts formed. In addition, the length of the graft may vary, and the graft copolymer often carries a fair amount of homopolymer. The ‘‘graft-onto’’ ... classification of polymers is based on molecular structure. According to this system, the polymer could be one of the following: 1. Linear-chain polymer 2. Branched-c...

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... Inc. higherthehardnessandmodulus.Anotherfactorthatplaysamajorrolein determiningthefinalpropertyofthepolymeristhechemicalnatureofthe surface.Mineralfillerssuchascalciumcarbonateandtitaniumdioxidepowder oftenhavepolarfunctionalgroups(e.g.,hydroxylgroups)onthesurface.To improvethewettingproperties,theyaresometimestreatedwithachemicalcalled acouplingagent. Couplingagentsarechemicalsthatareusedtotre...

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... A., and D. H. Sebastian, Principles of Polymerization Engineering, Wiley, New York, 1983. 4. Kumar, A., and S. K. Gupta, Fundamentals of Polymer Science and Engineering, Tata McGraw-Hill, New ... 571–585, 1987. 16. Khanna, A., Simulation, Modelling and Experimental Validation of Reversible Polymerization, Ph.D. thesis, Department of Chemical Engineering, Indian Institute of...

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... application of a vacuum in order to obtain a polymer Reaction Engineering of Step-Growth Polymerization 169 Copyright © 2003 Marcel Dekker, Inc. The total pressure P T is then the sum of partial ... the droplets to be of uniform size, obtain the rate of polymerization. If the polymerization is carried out to complete conversion, the resultant polymer would be in the form of...

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... polymerization. Thus, polymer radicals lie only within these polymer particles. The total number of polymer particles per unit volume of emulsion in the second stage of the emulsion polymerization is ... net effect of polymerization in stage II is the growth of polymer particles. If Eqs. (7.6.14a) and (7.6.14b) are divided, we get the average chain length of the polymer...

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... ! 1:39 ¼14;876 Inclosingthissection,wenotethat,fromEq.(8.6.8),½ZM=N A isthevolumeofa polymermoleculemultipliedby2.5,whereascN A =Misobviouslythenumberof polymermoleculesperunitvolume.Asaconsequence,½Zc,whichistheproduct ofthesetwoquantities,representsthevolumefractionofpolymermultipliedby 2.5.Ifthisnumberissmallcomparedtounity,thepolymersolutionisconsidered tobedilute;ifitisoftheorderofunit...

Ngày tải lên: 10/08/2014, 19:20