Insights into the Nucleation Role of Cellulose Crystals during Crystallization of Poly(Beta-hydroxybutyrate)
writer：Jianxiang Chen, Chunjiang Xu, Defeng Wu,* Keren Pan, Aiwen Qian, Yulu Sha, Li Wang
keywords：microcrystalline cellulose (MCC); nanocrystalline cellulose (NCC); poly(beta-hydroxybutyrate) (PHB); nucleation; spherulite.
source：期刊
specific source：Carbohydrate Polymers
Issue time：2015年
Carbohydrate
Polymers,
2015, 134C, 508-515
ABSTRACT:
Cellulose crystals, including microcrystalline cellulose
(MCC) and nanocrystalline cellulose (NCC), were used as the fillers to prepare green
composites with poly(beta-hydroxybutyrate) (PHB) by melt mixing for
crystallization study. The results reveal that the spherulite morphology of PHB and its composites depends
highly on the crystallization temperature, evolving from bundle shaped to ring-banded and finally
to irregular or zigzag textures with increase of temperature. However, the ring-banded structure is
strongly affected by the presence of cellulose crystals, and the average band space
decreases evidently with the addition of MCC or NCC. Compared with PHB/MCC
composite, PHB/NCC composite shows degraded spherulite structure with smaller band space and higher flocculation level of peak-to-valley
height because of stronger unbalanced
stresses in this system. Besides, cellulose crystals can act as good
heterogeneous nucleating agent to accelerate the crystallization of PHB, which
is further confirmed by the polarized optical
microscopy observations and the kinetic analyses.
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