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Study of molecular weight and chain branching architectures of natural rubber
Author(s) -
Qu Wei,
Zhu Yong,
Huang Guangsu,
Huang Cheng,
Luo MingChao,
Zheng Jing
Publication year - 2016
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.43975
Subject(s) - branching (polymer chemistry) , natural rubber , polymer science , chain (unit) , materials science , polymer chemistry , composite material , physics , astronomy
ABSTRACT The origin of the unique bimodal molecular weight distribution (MWD) of natural rubber (NR) has been controversial up to now. Studying the connection between particle size and molecular weight (MW) might be a key approach to revealing the mystery of NR architectures. In this study, through constructing NR models as objectives and employing gel‐permeation chromatography coupled to a viscosity detector as well as a multiangle laser light scattering detector (GPC‐DP‐MALLS), we have acquired branching parameters for NR from solid experiments and data fitting. It is found that small rubber particles (SRPs) and large rubber particles (LRPs) jointly construct the unique bimodal MWD of NR. SRPs with low branching numbers (Bn) and branching frequency (λ) are believed to be composed of almost linear rubber molecules having no chain‐end groups to be branched. In contrast, LRPs transform their MWD curve into a clear bimodal peak after transesterification and possess high Bn. Meanwhile, the formation of branch points in LRP by hydrogen bonding and ionic linkages has been clearly confirmed. Thus, a clear and exact structure of NR has been revealed for the first time. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci, 2016.