Ree Catalytic Isoprene With Polar Monomer Copolymer

Copolymerizations of isoprene(Ip) with polar monomers - acrylonitrile(AN), l,2-epoxyhexane(HO), 4-vinylpyridine(4-Vpy), maleic anhydride(MAn) and homo-polymerizations of 4-vinylpyndine and octamethyl cyclotetrasiloxane(D4) by rare earth coordination catalyst or rare earth solid superacid have been studied for the first time. It has been found that rare earth catalyst has high catalytic activity for all polymerizations above-mentioned.Block copolymerization of isoprene and acrylonitrile by rare earth catalyst composed of rare earth phosphonate, alkyl aluminum and electron donor has been studied in detail. Rare earth catalyst combined by 1,2-dibromoethane as electron donor was the most active catalyst. The copolymer can be obtained only after the certain monomer-feeding mode which Ip has been polymerized for a certain time before adding AN. Otherwise, AN homopolymer will be obtained. The optimum conditions for Ip-AN copolymerization with Nd(P204)3-Al(i-Bu)3-DBE catalytic system are as follows: [Nd]=0.01mol/L, Al/Nd= 15 (molar ratio), Br/Nd=3.0(molar ratio), toluene as solvent, Ip polymerization: 50癈,lhr; AN polymerization: 60癈, 7hr. The poly(Ip-b-AN) has two glass transition temperatures (Tg: -75.6癈, 96.5癈), excellent solvent-resistance and good mechanical property. It's breaking strength, yield strength, elongation and elastic modulus (AN content: 28.2%) are 0.53MPa, 0.50MPa, 261% and 1.86MPa, respectively.Block copolymerization of isoprene and 1,2-epoxyhexane by Nd(P204)3-Al(i-Bu)3-DBE catalyst has been investigated. The preferred conditions are: [Nd]=2x10-3mol/L, Al/Nd=10(molar ratio), Br/Nd=3 (molar ratio), toluene as solvent, sequence addition mode of feed, Ip: 50癈, 5hr; HO: 70癈, 48hr. Using the techniques of ER, 'H-NMR, GPC, the resultant copolymer has been characterized and proved to be blockcopolymers.The poly(Ip-b-HO) was used to immobilize glucose oxidase by electrochemical method for the first time. The influences of electrical potential, pH, temperature, substrate concentration and metal ion on the response electric current of the enzyme electrode have been studied. The poly(Ip-b-HO) glucose oxidase electrode has good operation stability , has typical kinetic characteristics and a diffusion controlled reaction. The apparent Michaelis constant and activation energy for the immobilized glucose oxidase are 32.2mmol/L and 37.2kJ/mol, respectively.Nd(P204)3-Al(i-Bu)3-DBE catalytic system is also effective catalyst for block copolymerization of isoprene with 4-vinylpyridine.The optimal conditions are as follows: [Ip]=[4-Vpy]=2moVL, [M]tol/[Nd]=1000, Al/Nd=15(molar ratio), Br/Nd = 3 (molar ratio), toluene as solvent, sequence feeding method, Ip. 50癈, 3hr, 4-Vpy: 30癈, 4hr. The Ip/4-Vpy block copolymer was characterized by IR, 'H-NMR.Alternating copolymerization of isoprene with maleic anhydride was carried out by rare earth coordination catalyst for the first time. The catalytic activity of various rare earth elements in Nd(naph)3 and ligands in NdL3 and organometallic compounds for the copolymerization has respectively the following order: Nd > Pr> La > Sm > Er; Na(naph)3 ?Nd(P204)3 > Nd(P507)3 > Nd(acac)3-2H20 > Nd(CF3COO)3; AlEt3 ?Al(i-Bu)3 > AlH(i-Bu)3 >Mg(n-Bu)2. The polymer yield is 70% with Nd(naph)3-AlEt3 catalytic system at following conditions: [M]to|=2.6mol/L ([Ip]=[MAn]=l), Al/Nd = 10(molar ratio), [Nd]=5xlO~3mol/L, toluene/dioxane=2/5(volume ratio) as solvent, 5癈, 2hr. The different feed ratios between Ip and MAn always result in the formation of a 1:1 copolymer.Homopolymer of 4-vinylpyridine with high molecular weight (Mr|: 20-90x104) was synthesized by rare earth coordination catalyst. The catalytic activity of various rare earth elements in Nd(P204)3 and alkylaluminum for copolymerization has respectively the following order: Nd ~ Sm ~ Ho ~ Dy ~ La > Pr ~Er 籝, Al(i-Bu)3 ~ AlH(i-Bu)2 ?AlEt3. Catalytic activity in various solvent shows follows sequence: dichloromethane > toluene ~ benzene > cyclohexane ?THE The monomer conversion is 100% by Nd(P204)3-Al(i-Bu)3 c...