Huang Kuan-Ying, Woo Eamor M, Nagarajan Selvaraj
Department of Chemical Engineering, National Cheng Kung University No. 1, University Road, Tainan 701-01, Taiwan.
Polymers (Basel). 2022 Feb 19;14(4):805. doi: 10.3390/polym14040805.
Amorphous poly(p-vinyl phenol) (PVPh) was added into semicrystalline poly(p-dioxanone) (PPDO) to induce a uniquely novel dendritic/ringed morphology. Polarized-light optical, atomic-force and scanning electron microscopy (POM, AFM, and SEM) techniques were used to observe the crystal arrangement of a uniquely peculiar cactus-like dendritic PPDO spherulite, with periodic ring bands not continuingly circular such as those conventional types reported in the literature, but discrete and detached to self-assemble on each of the branches of the lobs. Correlations and responsible mechanisms for the formation of this peculiar banded-dendritic structure were analyzed. The periodic bands on the top surface and interior of each of the cactus-like lobs were discussed. The banded pattern was composed of feather-like lamellae in random fractals alternately varying their orientations from the radial direction to the tangential one. The tail ends of lamellae at the growth front spawned nucleation cites for new branches; in cycles, the feather-like lamellae self-divided into multiple branches following the Fibonacci sequence to fill the ever-expanding space with the increase of the radius. The branching fractals in the sequence and the periodic ring-banded assembly on each of the segregated lobs of cactus-like dendrites were the key characteristics leading to the formation of this unique dendritic/ringed PPDO spherulite.
将无定形聚对乙烯基苯酚（PVPh）添加到半结晶聚对二氧环己酮（PPDO）中，以诱导出一种独特的新型树枝状/环状形态。使用偏光光学显微镜、原子力显微镜和扫描电子显微镜（POM、AFM和SEM）技术观察了一种独特的仙人掌状树枝状PPDO球晶的晶体排列，其具有周期性的环形带，不像文献中报道的传统类型那样是连续的圆形，而是离散的且在叶瓣的每个分支上自组装。分析了这种特殊带状树枝状结构形成的相关性和相关机制。讨论了每个仙人掌状叶瓣的顶面和内部的周期性带。带状图案由随机分形的羽毛状片晶组成，其取向从径向交替变化到切向。生长前沿的片晶末端产生了新分支的成核位点；循环中，羽毛状片晶按照斐波那契数列自分裂成多个分支，随着半径的增加填充不断扩大的空间。序列中的分支分形以及仙人掌状树枝状体每个分离叶瓣上的周期性环形带组装是导致形成这种独特的树枝状/环状PPDO球晶的关键特征。
