Long-Chain Branch Measurement in Substantially Linear Ethylene Polymers by 13C NMR with Halogenated Naphthalenes as Solvents

2017 ◽  
Vol 50 (20) ◽  
pp. 7959-7966 ◽  
Author(s):  
Zhe Zhou ◽  
Dan Baugh ◽  
Philip P. Fontaine ◽  
Yiyong He ◽  
Zhi Shi ◽  
...  
Keyword(s):  
13C Nmr ◽  
Long Chain ◽  
Long Chain Branch ◽  
Chain Branch

Long-Chain Branch Detection and Quantification in Ethylene–Hexene LLDPE with 13C NMR

2021 ◽  
Vol 54 (2) ◽  
pp. 757-762
Author(s):  
Zhe Zhou ◽  
Clemens Anklin ◽  
Rongjuan Cong ◽  
Xiaohua Qiu ◽  
Rainer Kuemmerle
Keyword(s):  
13C Nmr ◽  
Branch Detection ◽  
Long Chain ◽  
Long Chain Branch ◽  
Detection And Quantification ◽  
Chain Branch

Role of molecular architecture in interfacial self-adhesion of polyethylene films

2017 ◽  
Vol 33 (3) ◽  
pp. 235-261 ◽  
Author(s):  
Zahra Najarzadeh ◽  
Abdellah Ajji
Keyword(s):  
Molecular Weight ◽  
Adhesion Strength ◽  
Film Surface ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Molecular Architecture ◽  
Melt Temperature ◽  
Long Chain ◽  
Long Chain Branch ◽  
Chain Branch

The influence of molecular architecture on interfacial self-adhesion above polyethylene film melt temperature was examined in this study. The investigated molecular structures include molecular weight (Mw), molecular weight distribution, long chain branch amount and distribution and short chain branch among and along polyethylene chains. The long chain branches concentration was quantified using gel permeation chromatography and short branches concentration using nuclear magnetic resonance techniques. The adhesion strength was measured immediately after melt bonding using a T-Peel test. The results showed that increasing Mw resulted in higher adhesion strength in linear metallocene ethylene α-olefins. Low long chain branch concentrations hinder reptation motion and diffusion, and result in lower adhesion strength. Low density polyethylene with highly branched chains yielded very low self-adhesion. A drastic difference in adhesion strength between metallocene and conventional linear low density polyethylene is attributed to homogeneity versus heterogeneity of composition distribution. The low interfacial self-adhesion in conventional polyethylene was concluded to be due to enrichment of highly branched low molecular weight chains at the film surface. These segregated chains at the interface diffuse before the high molecular weight chains located in the bulk.

Using Solvents to Improve the Chemical Shift Differences Between Short-Chain Branch Methines and Long-Chain Branch Methines in Polyethylene Copolymers

2007 ◽  
Vol 257 (1) ◽  
pp. 158-161 ◽  
Author(s):  
Dan Baugh ◽  
O. David Redwine ◽  
Angela Taha ◽  
Ken Reichek ◽  
Janece Potter
Keyword(s):  
Chemical Shift ◽  
Short Chain ◽  
Long Chain ◽  
Long Chain Branch ◽  
Chain Branch

Kinetics of Long-Chain Branch Formation in Polyethylene

ACS Catalysis ◽  
2017 ◽  
Vol 8 (1) ◽  
pp. 725-737 ◽  
Author(s):  
Michael D. Jensen ◽  
Qing Yang ◽  
Youlu Yu ◽  
Max P. McDaniel
Keyword(s):  
Branch Formation ◽  
Kinetics Of ◽  
Long Chain ◽  
Long Chain Branch ◽  
Chain Branch

Revisiting the long-chain branch formation mechanism in metallocene catalyzed polyethylenes

2013 ◽  
Vol 4 (13) ◽  
pp. 3774 ◽  
Author(s):  
Vahid Karimkhani ◽  
Faramarz Afshar-Taromi ◽  
Saeed Pourmahdian ◽  
Florian J. Stadler
Keyword(s):  
Formation Mechanism ◽  
Branch Formation ◽  
Long Chain ◽  
Long Chain Branch ◽  
Chain Branch

Long chain branch polymer chain dimensions: application of topology to the Zimm–Stockmayer model

Polymer ◽  
2002 ◽  
Vol 43 (1) ◽  
pp. 203-222 ◽  
Author(s):  
Danail Bonchev ◽  
Eric J. Markel ◽  
Armenag H. Dekmezian
Keyword(s):  
Polymer Chain ◽  
Long Chain ◽  
Long Chain Branch ◽  
Chain Branch
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