苏州大学聚合物合成与改性作业答案Word文档格式.docx

1、PTFE （polytetrafluroethylene）3、 Please list the sources to generate free radicals.Thermal decomposition、photochemical decomposition、oxidation-reduction reaction、high energy particle radiation、sonication、plasma initiation、electrolytic initiation.4、 Please list main reactions of radicals.Radical addit

2、ion reaction、radical coupling reaction、radical disproportionation reaction、radical dissociation reaction、radical transfer reaction.5、 Please list three monomers which can be polymerized via radical, ionic and coordination polymerizations. Radical: styrene、vinyl chloride、ethylene、acrylonitrile、methac

3、rylamide; Ionic: isobutylene、isoprene、iospropyl vinyl ether、styrene； Coordination: propene、styrene、ethylene、isoprene;6、 Can 1,1-diphenylethylene be subjected to polymerization? Why?No, since the phenyl substitutes groups are bulky which can cause strong steric effects, 1,1-diphenylethylene can only

4、form dimer.7、 Please draw chemical structures of poly（styrene-alt-maleic anhydride）.8、 Please list elemental reactions of chain polymerization.Chain initiation、chain propagation、chain termination、chain transfer.9、 Please list the types of microstructures for monosubstituted vinyl monomers.Head-to-ta

5、il （1,3-placement, the substitutes are on alternate carbon atoms）:Head-to-head （1,2-placement）:10、Please list the types of chain transfer reaction in free radical polymerization and give two examples of chain transfer agents.Chain transfer to monomer, solvent （chain transfer agent）, initiator, and p

6、olymer;Chain transfer agent: carbon tetrachloride, 1-butanethiol, carbon tetrabromide, triethylamine.11、What are the characteristics of radical polymerization? It consists of four elementary reactionsinitiation, propagation, termination, and transfer; The rate of initiation is the lowest one, which

7、controls the overall rate of polymerization; Slow initiation, fast propagation, fast termination, and easy termination; The products only consists of monomer, polymers （active species, if possible）; High polymers exist as the polymerization begins; Conversion is increased by the extension of polymer

8、ization time; There is no reaction between monomer-monomer, monomer-polymer, and polymer-polymer; The concentration of monomer decreases and polymer increases as the polymerization goes on.12、Notions: efficiency of initiation, kinetic chain length, autoacceleration （gel effect）, radical life, polyme

9、rization rate, inhibition, retardation. Efficiency of initiation: the ratio of initiators which are used to initiate polymerization to initiators that decompose in the whole process of polymerization; Kinetic chain length: the average number of monomer molecules consumed per each radical which initi

10、ates a polymer chain, and it can be given by the ratio of polymerization rate to initiation rate; Autoacceleration: autoacceleration is a common phenomenon where the polymerization rate increases for certain period in radical polymerization which is caused by the increase of the system viscosity, th

11、us is also called gel effect; Radical life: the time from production to termination of radicals; Polymerization rate: describe how the polymerization concentration or conversion changes with the reaction time, which consists of three elementary reactions initiation, propagation, and termination, and

12、 can be expressed by the following equation: Inhibition: a phenomenon in which the reactivity of radicals and stopped and the polymerization is completely halted due to the addition of inhibitors; Retardation: a phenomenon in which only a portion of the radicals are stopped and polymerization occurs

13、 at a lower rate and lower polymer molecular weight due to the addition of retarders;13、Chemical structures: AIBN, BPO, KPS, cumyl hydroperoxide.AIBN （2,2-azobisisobutyronitrile） BPO （benzyl peroxide）KPS （potassium persulfate） cumyl hydroperoxide14、Please list the relation between degree of polymeri

14、zation and kinetic chain length.When no chain transfer occurs: Coupling termination:; Disproportionation termination: The two modes coexist: C、D represent the percentage of coupling and disproportionationWhen chain transfer occurs: 15、Please explain basic principles of dilatometer method. The princi

15、ples of dilatometer method are based on the linear relationship between the volume contraction and the conversion of the reaction system: Where is the specific volume of monomer, is the specific volume of polymer, and K represents the rate of change of volume when the conversion is 100%. The convers

16、ion （C%） has a linear relationship with the volume contraction: is the original volume of the system, and denotes the contraction value of volume. The dilatometer consists of two parts: the lower part is the reactor, and the upper one is calibrated capillary. By measuring the volume contraction valu

17、e at different time, we can get the conversion change with time, and get the polymerization rate.Chapter 21、 What are basic features of living polymerization systems? Constant number of polymer chains; No permanent chain stopping reactions; Control of chain growth; Dormant and active states; Narrow

18、molecular weight distribution; The plot of Mn versus monomer conversion is linear; Synthesis of block copolymers, star polymers and comb polymer; Synthesis of telechelic polymers （control of end groups）. 2、 Please list the main types of “living”/controlled radical polymerization. Reversible hemolyti

19、c cleavage: NMP （nitroxide-mediated polymerization, a special kind of SFRP, stable free-radical polymerization） and ATRP （atom transfer radical polymerization）; Chain transfer process: addition fragmentation, RAFT （reversible addition-fragmentation chain transfer polymerization）, CCTP （catalytic cha

20、in transfer polymerization）; Iniferters methods; Organotellurium and boroxyl-based initiators.3、 Please list the basic mechanism and application of ATRP.ATRP is a kind of transition metal mediated living radical polymerization, and its mechanism is shown below:OrApplications of ATRP: To prepare well

21、-defined macromolecules with predetermined Mw and low polydispersity Mw/Mn , 300 Mn 200,000）; To control macromolecular architecture （linear, star, polymer brush, dendritic）; To control microstructure of macromolecules （homopolymer, alternating, block, graft）; To prepare macromonomers and functional

22、ized polymers with COOH, OH, NR1R2 and vinyl groups （telechelic, multifunctional, end-functionalized）.4、 Please list the basic mechanism and application of RAFT polymerization, and describe the primary roles of Z and R groups of RAFT agent.Mechanism:Application: Synthesis of block copolymer, gradien

23、t copolymer, and graft copolymer; Synthesis of polymers with different architectures, like telechelic copolymer, star copolymer, hyperbranched copolymer, and polymers with network; Introducing functionalities into polymers.Primary roles of Z and R:Z serves as stabilizing groups, like phenyl, alkyl g

24、roups; R serves as reinitiating groups, and should be cleavable, like isopropyl phenyl group.Chapter 51、 Take Na-naphthalene based anionic polymerization of styrene for example, please describe the basic mechanism and application of living anionic polymerization. To synthesize a monodisperse polymer

25、; To measure the anionic polymerization rate; To prepare a block copolymer; To prepare a telechelic polymer.2、 Please describe main subclasses of dendritic polymers.Dendrimers、dendrons、hyperbranched polymers、dendrigraft polymers、dendronized polymers.3、 What is dendrimer? How about its main applicati

26、ons?Dendrimer is repetitively branched molecule, which is typically symmetric around the core, and often adopts a spherical three-dimensional morphology.Dendrimer has lot of applications: suprachemistry, catalyst, drug delivery, gene delivery, optics, sensors, blood substitution, nanoparticles, and

27、other fields.4、 Please list three types of dendrimers. What is the repeating unit of Tomalia-type poly（amidoamine） dendrimer?Tomalia-type poly（amidoamine） （PAMAM）、Newkomes arborol dendrimers、Phosphorus containing dendrimers、Frchet-type poly（benzylether）.Repeating unit of PAMAM dendrimers:5、 Please l

28、ist the main methods to synthesize dendrimers. Divergent synthesis: multiplicative growth from a central core; Convergent synthesis: preparation starting from what will become the periphery of the molecule and progressing inward; Click chemistry: preparation based on Diels-Alder reactions, thiol-ene reactions, and azide-alkyne reactions.6、 By assuming the core functionality is m, and each branching point has three linking pos