One-Pot Process of Preparing Long Chain Branched Polypropylene Using <i>C</i><sub>2</sub>-Symmetric Metallocene Complex and a “T” Reagent

Langston, Justin A.; Dong, Jin‐Yong; Chung, Tze-chiang

doi:10.1021/ma0506841

Cited by 37 publications

(30 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The introduction of long‐chain branches in polymer chemistry can modify the melt processibility and flow behavior . For example, long‐chain branches can promote the desirable rheological properties in melt processing, such as a pronounced shear thinning effect, which is beneficial for blowing and casting films, injection and blow molding, and thermoforming.…”

Section: Resultsmentioning

confidence: 99%

Branched poly(1,4-butylene carbonate-co-terephthalate)s: LDPE-like semicrystalline thermoplastics

Park

Chun

Jeon

et al. 2015

J. Polym. Sci. Part A: Polym. Chem.

View full text Add to dashboard Cite

Branched poly[1,4-butylene carbonate-co-terephthalate]s (PBCTs) have been synthesized by the addition of a small amount of glycerol propoxylate (1) or pentaerythritol (2) in the polycondensation of 1,4-butanediol, dimethyl carbonate, and dimethyl terephthalate. To avoid gel formation, the feed amount of 1 or 2 was carefully controlled at below 0.5 mol % for 1 and below 0.3 mol % for 2. When feed of 1 or 2 was used, a high-molecular weight melt state (M w 180,000 g/mol) was reached in a total reaction time of 5.5 to 6.5 h with a yield higher than 90%. The generated PBCTs were a semicrystalline polymer (T g 5 C and T m 120 C) when the terephthalate content (F [TPA] ) was 45 to 50 mol %. The crystallization rate

show abstract

Section: Resultsmentioning

confidence: 99%

Branched poly(1,4-butylene carbonate-co-terephthalate)s: LDPE-like semicrystalline thermoplastics

Park

Chun

Jeon

et al. 2015

J. Polym. Sci. Part A: Polym. Chem.

View full text Add to dashboard Cite

show abstract

“…We had also studied asymmetric diene comonomers that contain a α‐olefin and a styrenic moiety, as illustrated in Scheme . The objective is to incorporate pending styrene groups into the polyolefin flexible side chains, which are facile for a broad range of reactions, including free radical, cationic, and anionic functionalization and grafting reactions.…”

Section: Functionalization Of Polypropylene Using “Reactive” Comonomersmentioning

confidence: 99%

Functionalization of Polypropylene by the Combination of Metallocene Catalysts and Reactive Comonomers

Chung

2013

Macro Reaction Engineering

View full text Add to dashboard Cite

This paper summarizes a functionalization approach that can prepare functional PP with desirable molecular structures, including functional groups, microstructures, high molecular weight, and narrow molecular weight and composition distributions. A newly‐developed catalysis technology with several designed “reactive” comonomers to circumvent the inevitable deactivation of the transition metal cationic active site by functional groups in the direct polymerization process has been applied. The reactive comonomers, containing organoborane, benzylic protons (ϕ‐CH3), and styrene moieties exhibit three essential properties, including (a) stability with the active site, (b) solubility in the polymerization media, and (c) versatility for interconversion to desirable functional groups under mild reaction conditions. With proper choice of metallocene catalysts, they resemble to high a‐olefin monomers and can be effectively incorporated into the PP structure. In addition to the interconversion of the incorporated reactive sites to the desirable functional groups in PP copolymers, some reactive sites have been also transformed into “living” radical or anionic initiators to initiate graft‐from polymerization of polar monomers to obtain PP graft copolymers.

show abstract

“…13 Generally, the grafting method involved multiple post-polymerization procedures and extra separation to obtain pure LCBPPs. [18][19][20][21] However, the copolymerization behaviors of propylene with non-conjugated diolefins are extremely complicated. However, only a few specific catalysts which can effectively produce vinyl-ended macro-monomer through -methyl elimination and incorporate it into polymer chain have been discovered.…”

Section: Introductionmentioning

confidence: 99%

Copolymerization of propylene with Si-containing α,ω-diolefins: how steric hindrance of diolefins affects long chain branch formation

Wang

Zhang

et al. 2016

Polym. Chem.

View full text Add to dashboard Cite

By using pyridylamido-hafnium/[Ph3C][B(C6F5)4]/Al i Bu3 catalytic system, a series of long chain branched isotactic polypropylenes (LCBPPs) were in situ synthesized by copolymerization of propylene with Si-containing monomers 4,4-dimethyl-4-sila-1,6-heptadiene (DMS), 4-methyl-4-phenyl-4-sila-1,6-heptadiene (MPS), 4,4-diphenyl-4-sila-1,6-hepta-diene (DPS), or 4-methyl-4-vinyl-4-sila-1,6-heptadiene (MVS). The effects of the substituent groups on copolymerization behavior and topological structure were further investigated. The substituent groups decreased the cyclization tendency of the diallylsilane, which increased the probability of the insertion of the pendent vinyl groups into other polymer chain. Thus, LCBPPs could be easily prepared under mild conditions by exquisitely controlling comonomer structure and polymerization conditions such as initial concentration of comonomer, the dosage of chain transfer agent (CTA) and reaction time. The presence of LCB structure was confirmed by characterization of SEC equipped with triple detectors, small-amplitude dynamic rheological measurements and uniaxial extension. The introduction of LCBs endowed PP with improved rheological behavior and melt strength, which made the resultant LCBPPs possess potential application in thermal process such as blow molding and foaming. A series of long chain branched isotactic polypropylenes (LCBPPs) were in situ synthesized by copolymerization of propylene with diallylsilanes. The substituent groups can efficiently suppress cyclization of the diolefin and significantly improve LCB formation efficiency during the copolymerization of propylene and diallylsilane.

show abstract

One-Pot Process of Preparing Long Chain Branched Polypropylene Using C₂-Symmetric Metallocene Complex and a “T” Reagent

Cited by 37 publications

References 20 publications

Branched poly(1,4-butylene carbonate-co-terephthalate)s: LDPE-like semicrystalline thermoplastics

Branched poly(1,4-butylene carbonate-co-terephthalate)s: LDPE-like semicrystalline thermoplastics

Functionalization of Polypropylene by the Combination of Metallocene Catalysts and Reactive Comonomers

Copolymerization of propylene with Si-containing α,ω-diolefins: how steric hindrance of diolefins affects long chain branch formation

Contact Info

Product

Resources

About

One-Pot Process of Preparing Long Chain Branched Polypropylene Using C2-Symmetric Metallocene Complex and a “T” Reagent

Cited by 37 publications

References 20 publications

Branched poly(1,4-butylene carbonate-co-terephthalate)s: LDPE-like semicrystalline thermoplastics

Branched poly(1,4-butylene carbonate-co-terephthalate)s: LDPE-like semicrystalline thermoplastics

Functionalization of Polypropylene by the Combination of Metallocene Catalysts and Reactive Comonomers

Copolymerization of propylene with Si-containing α,ω-diolefins: how steric hindrance of diolefins affects long chain branch formation

Contact Info

Product

Resources

About

One-Pot Process of Preparing Long Chain Branched Polypropylene Using C₂-Symmetric Metallocene Complex and a “T” Reagent