1995 Fiscal Year Final Research Report Summary
Synthesis of isotactic polypropylene-based block copolymers
| Project/Area Number |
06651019
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
高分子合成
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
SHIONO Takeshi Tokyo Institute of Technology, Research Laboratory of Resources Utilization, Associate Professor, 資源化学研究所, 助教授 (10170846)
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| Co-Investigator(Kenkyū-buntansha) |
SOGA Kazuo Japan Advanced Institute of Science and Technology EAST,Material Science Departm, 材料科学, 教授 (10026180)
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| Project Period (FY) |
1994 – 1995
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| Keywords | isotactic polypropylene / poly (methyl methacrylate) / block copolymer / metallocene catalyst / chain transfer / Ziegler-Natta catalyst / chain end functionalizaton / Grignard reagent |
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| Research Abstract |
Isotactic poly (propene) (PP) having a terminal vinylidene group (number average molecular weight=5,300, melting point=114ﾟC) was prepared with the ethylenebis (4,5,6,7-tetrahydro-1-indenyl) zirconium dichloride-methylaluminoxane catalyst system. The polymer produced was treated with borane-dimethylsulfide in toluene, followed by reacting with pentane-1,5-di (magnesium bromide) to obtain magnesium bromide (MgBr) -terminated isotactic PP.The polymer was brought into contact with iodine to give isotactic PP having an iodine group at the chain end in about a 85% yield. Polymerization of methyl methacrylate was then conducted at -78ﾟC using the MgBr-terminated PP as an initiator to synthesize isotactic PP-block-poly (methyl methacrylate) copolymer.
In order to apply this method to the synthesis of A-B-A type block copolymers, an attempt was made to prepare alpha, omega-divinyl PP.We have previously reported that the Zn-polymer bonds of PP obtained with the TiCl_3-AlEt_2Cl-ZnEt_2 catalyst ca
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n be converted to vinyl groups in fairly good yield by the coupling reaction with allyl bromide. Therefore, bis (3-butenyl) zinc (BBZ) and bis (7-octenyl) zinc (BOZ) were synthesized and used as cocatalyst and/or chain transfer reagent combined with TiCl_3. These catalyst systems gave isotactic poly (propene), of which melting points were around 160ﾟC.The bis (alkenyl) zinc compounds acted as a chain transfer reagent to give zinc-terminated polymers with low molecular weight.IR,^1H NMR and ^<13>C NMR analyzes of the produced polymers indicated the incorporation of 7-octenyl group at the initiation chain end. However, 3-butenyl group was not observed, which may be probably due to back-biting cyclization. In addition, BOZ could copolymerize with propene to give PP which had Zn-carbon bonds in side chains. The zinc-carbon bond at the termination end and the side chains were converted to vinyl groups by coupling with allyl bromide to obtain alpha, omega-divinyl PP having a small amount of 8-nonenyl groups as side chain.
Synthesis of block copolymers from the alpha, omega-divinyl PP by the method described above are now being carried out. Less
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