Unwinding of spherulites in polymers
WebAdjusting the rate of crystallization is helpful in reducing the size of crystals in semicrystalline polymers. Poly(4,4′-aminocyclohexyl methylene dodecanedicarboxylamide), named PA PACM12, [] is a transparent microcrystalline cycloaliphatic polyamide and its chemical structure is shown in Figure 1E.The crystallization speed of PA PACM12 is … WebPolymer Journal, Vol. 40, No. 10, pp. 1005–1009, 2008 #2008 The Society of Polymer Science, Japan 1007 large retardation in the PTT spherulite which was much larger than …
Unwinding of spherulites in polymers
Did you know?
Webclassical semicrystalline polymers such as PP during processing can, for instance, be controlled with nucleating agents. While spherulites are aimed to be very small in this … WebJul 31, 2024 · As shown in Figure 4f, the Raman peak for an excitation perpendicular to the orientation direction is shifted about 3 cm −1 toward higher energies with respect to parallel excitation, indicating that a higher ratio of amorphous polymer chains lies in perpendicular direction. 27 In regions where the formation of spherulites has been suppressed by an …
WebWhen crystallization behaviour semi-crystalline polymers are referred, the term spherulite always comes into the picture. Spherulites is the crystalline entity that is responsible giving different characteristics such as melting and crystallization temperatures to semi-crystalline polymers in contrast to amorphous polymers [3]. WebJan 16, 2001 · The dynamic growth processes of lamellae and spherulites of a polymer (BA-C8) synthesized by condensation polymerization of bisphenol A and 1,8-dibromooctane were directly observed using an atomic force microscope at 25 ± 1 °C. The phase shift measured at the tip of growing lamellae is lower than the phase shifts of the other regions of the …
WebThe article then focuses on semicrystalline polymers with semiconducting properties. From classical melt crystallization toward solvent vapor annealing, different strategies of … WebAug 19, 2006 · Morphology of polyethylene spherulites has been investigated by the low-dose technique using transmission electron microscopy (TEM) in a scanning mode for …
WebNov 13, 2015 · The addition of the whole wave plate (upper photomicrograph) confirms the tangential arrangement of the polymer chains. The banding occuring in these spherulites indicates slow cooling of the melt allowing the polymer chains to grow out in spirals. This information on thermal history is almost impossible to collect by any other technique.
WebSep 1, 1999 · The morphology of spherulites shows that they form because of a short-range force operative at the branch points of dominant lamellae causing them to diverge at non … the palpable leprosy of pollutionWebAn investigation on polymer spherulites is being described in three parts. Part I (the present paper) describes the various effects observed under the polarizing microscope. These are … the palo verde case is significant because itWebThe extinction patterns between crossed nicols shown by two types of arrays of uniaxial crystals have been investigated. The arrays were (a) a disk whose radii were twisted … the palpebrae quizletWebCrystallinity refers to the degree of structural order of a solid. In a crystal, the arrangement of atoms or molecules is consistent and repetitive. Many materials such as glass ceramics and some polymers can be prepared in such a way as to produce a mixture of crystalline and amorphous regions. Crystallisabilty • Crystallisabilty is the ... shutterstock charge on credit cardWebPolymer Spherulites. D.C. Bassett, in Encyclopedia of Materials: Science and Technology, 2002 4 Spherulitic Textures. Spherulites are not unique entities but have textures varying … the palpa companyWebJul 15, 2024 · Affiliations 1 Graduate Institute of Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan, ROC.; 2 Graduate Institute of Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan, ROC; Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taoyuan 33305, Taiwan, ROC; Department of Materials … the palpatory method helps to determine the:WebApr 19, 2024 · Various spherulites or spherulitic crystals are widely encountered in polymeric materials when crystallized from viscous melts or concentrated solutions. … shutterstock child face