Tuning polymerization performance in ethylene–propylene copolymerization using a constrained geometry titanium catalyst [t-BuNSiMe2(Me4Cp)]TiMe2: Insights from random and block copolymerization studies

In this study, a titanium-based constrained geometry catalyst, [t-BuNSiMe2(Me4Cp)]TiMe2, was synthesized and activated with methylaluminoxane for ethylene-propylene random and block copolymerization. The catalyst exhibited optimal activity at 70°C, yielding random copolymer chains with trace amounts...

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Main Authors: Fengtao Li, Jing Wang, Xuelian He
Format: Article
Language:English
Published: Iran Polymer and Petrochemical Institute 2025-06-01
Series:Polyolefins Journal
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Online Access:http://poj.ippi.ac.ir/article_2109_739984af501e7e3c6f6bb93791d39842.pdf
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author Fengtao Li
Jing Wang
Xuelian He
author_facet Fengtao Li
Jing Wang
Xuelian He
author_sort Fengtao Li
collection DOAJ
description In this study, a titanium-based constrained geometry catalyst, [t-BuNSiMe2(Me4Cp)]TiMe2, was synthesized and activated with methylaluminoxane for ethylene-propylene random and block copolymerization. The catalyst exhibited optimal activity at 70°C, yielding random copolymer chains with trace amounts of long polyethylene crystalline segments. When the ethylene content fell below 35%, random copolymers failed to crystallize. The block copolymerization system achieved maximum catalytic activity at a reaction temperature of 50°C and an ethylene block duration of 10 minutes. Shorter ethylene block durations correlated inversely with enhanced catalytic activity, increased molecular weight (peaking at 2.88 × 105 g/mol), and a narrower molecular weight distribution. The predominant component comprised extended PPP segments, constituting over 50% of the total copolymer composition. Within the polymer chains, propylene monomers were primarily incorporated as PPP and PPE structural motifs. Moreover, a progressive decrease in [PPP] content was observed with increasing ethylene block duration, whereas [PPE] content exhibited the opposite trend. This inverse relationship suggested that PPP segments gradually transform into PPE configurations via ethylene monomer insertion. These findings demonstrated that product structure and properties can be effectively tuned by adjusting initial monomer feed ratios or the timing of monomer block introduction.
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spelling doaj-art-0126903aa5454fdbaeb4ee62a528b0412025-08-20T03:12:43ZengIran Polymer and Petrochemical InstitutePolyolefins Journal2322-22122345-68682025-06-0112212914010.22063/poj.2025.35685.13572109Tuning polymerization performance in ethylene–propylene copolymerization using a constrained geometry titanium catalyst [t-BuNSiMe2(Me4Cp)]TiMe2: Insights from random and block copolymerization studiesFengtao Li0Jing Wang1Xuelian He2Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSinopec Shanghai Petrochemical Co., LtdShanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai 200237, ChinaIn this study, a titanium-based constrained geometry catalyst, [t-BuNSiMe2(Me4Cp)]TiMe2, was synthesized and activated with methylaluminoxane for ethylene-propylene random and block copolymerization. The catalyst exhibited optimal activity at 70°C, yielding random copolymer chains with trace amounts of long polyethylene crystalline segments. When the ethylene content fell below 35%, random copolymers failed to crystallize. The block copolymerization system achieved maximum catalytic activity at a reaction temperature of 50°C and an ethylene block duration of 10 minutes. Shorter ethylene block durations correlated inversely with enhanced catalytic activity, increased molecular weight (peaking at 2.88 × 105 g/mol), and a narrower molecular weight distribution. The predominant component comprised extended PPP segments, constituting over 50% of the total copolymer composition. Within the polymer chains, propylene monomers were primarily incorporated as PPP and PPE structural motifs. Moreover, a progressive decrease in [PPP] content was observed with increasing ethylene block duration, whereas [PPE] content exhibited the opposite trend. This inverse relationship suggested that PPP segments gradually transform into PPE configurations via ethylene monomer insertion. These findings demonstrated that product structure and properties can be effectively tuned by adjusting initial monomer feed ratios or the timing of monomer block introduction.http://poj.ippi.ac.ir/article_2109_739984af501e7e3c6f6bb93791d39842.pdfconstrained geometrytitanium-based catalystethylene-propylene copolymerizationethylene–propylene copolymersblock copolymerization
spellingShingle Fengtao Li
Jing Wang
Xuelian He
Tuning polymerization performance in ethylene–propylene copolymerization using a constrained geometry titanium catalyst [t-BuNSiMe2(Me4Cp)]TiMe2: Insights from random and block copolymerization studies
Polyolefins Journal
constrained geometry
titanium-based catalyst
ethylene-propylene copolymerization
ethylene–propylene copolymers
block copolymerization
title Tuning polymerization performance in ethylene–propylene copolymerization using a constrained geometry titanium catalyst [t-BuNSiMe2(Me4Cp)]TiMe2: Insights from random and block copolymerization studies
title_full Tuning polymerization performance in ethylene–propylene copolymerization using a constrained geometry titanium catalyst [t-BuNSiMe2(Me4Cp)]TiMe2: Insights from random and block copolymerization studies
title_fullStr Tuning polymerization performance in ethylene–propylene copolymerization using a constrained geometry titanium catalyst [t-BuNSiMe2(Me4Cp)]TiMe2: Insights from random and block copolymerization studies
title_full_unstemmed Tuning polymerization performance in ethylene–propylene copolymerization using a constrained geometry titanium catalyst [t-BuNSiMe2(Me4Cp)]TiMe2: Insights from random and block copolymerization studies
title_short Tuning polymerization performance in ethylene–propylene copolymerization using a constrained geometry titanium catalyst [t-BuNSiMe2(Me4Cp)]TiMe2: Insights from random and block copolymerization studies
title_sort tuning polymerization performance in ethylene propylene copolymerization using a constrained geometry titanium catalyst t bunsime2 me4cp time2 insights from random and block copolymerization studies
topic constrained geometry
titanium-based catalyst
ethylene-propylene copolymerization
ethylene–propylene copolymers
block copolymerization
url http://poj.ippi.ac.ir/article_2109_739984af501e7e3c6f6bb93791d39842.pdf
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AT jingwang tuningpolymerizationperformanceinethylenepropylenecopolymerizationusingaconstrainedgeometrytitaniumcatalysttbunsime2me4cptime2insightsfromrandomandblockcopolymerizationstudies
AT xuelianhe tuningpolymerizationperformanceinethylenepropylenecopolymerizationusingaconstrainedgeometrytitaniumcatalysttbunsime2me4cptime2insightsfromrandomandblockcopolymerizationstudies