Effects of branching characteristics and copolymer composition distribution on non-isothermal crystallization kinetics of metallocene LLDPEs

Mohammad Ashraful Islam; Ibnelwaleed A. Hussein; Muhammad Atiqullah

doi:10.1016/j.eurpolymj.2006.10.019

Effects of branching characteristics and copolymer composition distribution on non-isothermal crystallization kinetics of metallocene LLDPEs

Mohammad Ashraful Islam, Ibnelwaleed A. Hussein^*, Muhammad Atiqullah

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

36 Scopus citations

Abstract

The effects of branch content (BC) and copolymer composition distribution (CCD) on the non-isothermal crystallization kinetics of metallocene m-LLDPEs were studied using modified Avrami analysis, modulated differential scanning calorimetry (MDSC), and Crystaf. Several m-LLDPEs and an m-HDPE - all having comparable M_w and PDI - were experimented. In addition, a ZN-LLDPE was used for comparison purposes. The branch content, unlike the used cooling rates (2-6 °C/min), significantly affected the crystallization behavior. Crystallization peak temperature, T_c^peak, decreased linearly with increasing BC. All the m-LLDPEs showed primary and secondary crystallizations. The secondary crystallization showed to be more pronounced at high BC. The primary crystallization Avrami parameter n for m-HDPE ranged between 3.72 and 4.50, indicating spherulitic crystal growth whereas that for the m-LLDPEs, varied from 2.02 to 5.70. The ZN-LLDPE (having broader composition distribution) offered higher values of T_c^onset and T_c^peak than the m-LLDPEs with similar BC, M_w, and PDI. It, unlike the m-LLDPEs and m-HDPE, fairly agreed with the crystallization kinetic model proposed by Liu et al. The lamella thickness of the m-LLDPEs, L, calculated as per Gibbs-Thomson equation, showed to be in the range 2-16 nm, depending on BC and it decreased approximately following the relationship: L (nm) = 15.0 e^(-0.0498BC).

Original language	English
Pages (from-to)	599-610
Number of pages	12
Journal	European Polymer Journal
Volume	43
Issue number	2
DOIs	https://doi.org/10.1016/j.eurpolymj.2006.10.019
State	Published - Feb 2007

Bibliographical note

Funding Information:
The authors are grateful to King Abdul Aziz City for Science and Technology (KASCT) for providing financial support for this research under research Grant # AT-22-16. They also acknowledge the support of King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia. Acknowledgement is also extended to ExxonMobil for providing the polymer samples and to Polychar at Spain for the Crystaf analysis.

Keywords

Branch content
Copolymer composition distribution (CCD)
MDSC
Metallocene LLDPE
Non-isothermal crystallization

ASJC Scopus subject areas

General Physics and Astronomy
Organic Chemistry
Polymers and Plastics
Materials Chemistry

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10.1016/j.eurpolymj.2006.10.019

Cite this

@article{acaeb31e3e9b408cb0bc9f2976544f87,

title = "Effects of branching characteristics and copolymer composition distribution on non-isothermal crystallization kinetics of metallocene LLDPEs",

abstract = "The effects of branch content (BC) and copolymer composition distribution (CCD) on the non-isothermal crystallization kinetics of metallocene m-LLDPEs were studied using modified Avrami analysis, modulated differential scanning calorimetry (MDSC), and Crystaf. Several m-LLDPEs and an m-HDPE - all having comparable Mw and PDI - were experimented. In addition, a ZN-LLDPE was used for comparison purposes. The branch content, unlike the used cooling rates (2-6 °C/min), significantly affected the crystallization behavior. Crystallization peak temperature, Tcpeak, decreased linearly with increasing BC. All the m-LLDPEs showed primary and secondary crystallizations. The secondary crystallization showed to be more pronounced at high BC. The primary crystallization Avrami parameter n for m-HDPE ranged between 3.72 and 4.50, indicating spherulitic crystal growth whereas that for the m-LLDPEs, varied from 2.02 to 5.70. The ZN-LLDPE (having broader composition distribution) offered higher values of Tconset and Tcpeak than the m-LLDPEs with similar BC, Mw, and PDI. It, unlike the m-LLDPEs and m-HDPE, fairly agreed with the crystallization kinetic model proposed by Liu et al. The lamella thickness of the m-LLDPEs, L, calculated as per Gibbs-Thomson equation, showed to be in the range 2-16 nm, depending on BC and it decreased approximately following the relationship: L (nm) = 15.0 e(-0.0498BC).",

keywords = "Branch content, Copolymer composition distribution (CCD), MDSC, Metallocene LLDPE, Non-isothermal crystallization",

author = "Islam, \{Mohammad Ashraful\} and Hussein, \{Ibnelwaleed A.\} and Muhammad Atiqullah",

note = "Funding Information: The authors are grateful to King Abdul Aziz City for Science and Technology (KASCT) for providing financial support for this research under research Grant \# AT-22-16. They also acknowledge the support of King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia. Acknowledgement is also extended to ExxonMobil for providing the polymer samples and to Polychar at Spain for the Crystaf analysis. ",

year = "2007",

month = feb,

doi = "10.1016/j.eurpolymj.2006.10.019",

language = "English",

volume = "43",

pages = "599--610",

journal = "European Polymer Journal",

issn = "0014-3057",

publisher = "Elsevier Ltd.",

number = "2",

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TY - JOUR

T1 - Effects of branching characteristics and copolymer composition distribution on non-isothermal crystallization kinetics of metallocene LLDPEs

AU - Islam, Mohammad Ashraful

AU - Hussein, Ibnelwaleed A.

AU - Atiqullah, Muhammad

N1 - Funding Information: The authors are grateful to King Abdul Aziz City for Science and Technology (KASCT) for providing financial support for this research under research Grant # AT-22-16. They also acknowledge the support of King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia. Acknowledgement is also extended to ExxonMobil for providing the polymer samples and to Polychar at Spain for the Crystaf analysis.

PY - 2007/2

Y1 - 2007/2

N2 - The effects of branch content (BC) and copolymer composition distribution (CCD) on the non-isothermal crystallization kinetics of metallocene m-LLDPEs were studied using modified Avrami analysis, modulated differential scanning calorimetry (MDSC), and Crystaf. Several m-LLDPEs and an m-HDPE - all having comparable Mw and PDI - were experimented. In addition, a ZN-LLDPE was used for comparison purposes. The branch content, unlike the used cooling rates (2-6 °C/min), significantly affected the crystallization behavior. Crystallization peak temperature, Tcpeak, decreased linearly with increasing BC. All the m-LLDPEs showed primary and secondary crystallizations. The secondary crystallization showed to be more pronounced at high BC. The primary crystallization Avrami parameter n for m-HDPE ranged between 3.72 and 4.50, indicating spherulitic crystal growth whereas that for the m-LLDPEs, varied from 2.02 to 5.70. The ZN-LLDPE (having broader composition distribution) offered higher values of Tconset and Tcpeak than the m-LLDPEs with similar BC, Mw, and PDI. It, unlike the m-LLDPEs and m-HDPE, fairly agreed with the crystallization kinetic model proposed by Liu et al. The lamella thickness of the m-LLDPEs, L, calculated as per Gibbs-Thomson equation, showed to be in the range 2-16 nm, depending on BC and it decreased approximately following the relationship: L (nm) = 15.0 e(-0.0498BC).

AB - The effects of branch content (BC) and copolymer composition distribution (CCD) on the non-isothermal crystallization kinetics of metallocene m-LLDPEs were studied using modified Avrami analysis, modulated differential scanning calorimetry (MDSC), and Crystaf. Several m-LLDPEs and an m-HDPE - all having comparable Mw and PDI - were experimented. In addition, a ZN-LLDPE was used for comparison purposes. The branch content, unlike the used cooling rates (2-6 °C/min), significantly affected the crystallization behavior. Crystallization peak temperature, Tcpeak, decreased linearly with increasing BC. All the m-LLDPEs showed primary and secondary crystallizations. The secondary crystallization showed to be more pronounced at high BC. The primary crystallization Avrami parameter n for m-HDPE ranged between 3.72 and 4.50, indicating spherulitic crystal growth whereas that for the m-LLDPEs, varied from 2.02 to 5.70. The ZN-LLDPE (having broader composition distribution) offered higher values of Tconset and Tcpeak than the m-LLDPEs with similar BC, Mw, and PDI. It, unlike the m-LLDPEs and m-HDPE, fairly agreed with the crystallization kinetic model proposed by Liu et al. The lamella thickness of the m-LLDPEs, L, calculated as per Gibbs-Thomson equation, showed to be in the range 2-16 nm, depending on BC and it decreased approximately following the relationship: L (nm) = 15.0 e(-0.0498BC).

KW - Branch content

KW - Copolymer composition distribution (CCD)

KW - MDSC

KW - Metallocene LLDPE

KW - Non-isothermal crystallization

UR - https://www.scopus.com/pages/publications/33846400850

U2 - 10.1016/j.eurpolymj.2006.10.019

DO - 10.1016/j.eurpolymj.2006.10.019

M3 - Article

AN - SCOPUS:33846400850

SN - 0014-3057

VL - 43

SP - 599

EP - 610

JO - European Polymer Journal

JF - European Polymer Journal

IS - 2

ER -

Effects of branching characteristics and copolymer composition distribution on non-isothermal crystallization kinetics of metallocene LLDPEs

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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