Structure Evolution of Polyethylene in Sequential Biaxial Stretching along the First Tensile Direction

Abstract

Two linear low-density polyethylene samples (PE-A and PE-B), with similar melt index and molecular weight but different molecular structures, were used to explore the structural evolution during sequential biaxial stretching. Only PE-A could be successfully stretched into a film with the biaxial draw ratio of 6 × 6. The interlamellae crossing adjacent lamellar stacks were observed in PE-A but not in PE-B, which could increase the lateral tie connection. Moreover, the amount of fibril was less in PE-A than that in PE-B and the fibrillar structure lacked tie chains between each other. In addition, the newly formed lamellae in PE-A (derived from fine lamellae) could lock the molecular chains of different crystals, which increased the lateral connection via anchoring the tie chains from adjacent lamellae. Therefore, the above specific structures increased the lateral connection and were beneficial for biaxial stretching. Furthermore, the relationship between molecular structure and condensed structure was also established.

Metallo‐supramolecular Crosslinked Polyurethanes

“…While these data do not provide conclusive proof of a discotic HS domain shape, rotation and extension of discotic structures should be analogous to morphological changes observed in lamellar structures, such as polyethylene (PE), undergoing tensile deformation. Data from SAXS studies of PE using in situ tensile deformation show a high degree of similarity to those observed here . Indeed, additional analysis of the PUBIP SAXS data at high elongations, where the PTMO has crystallized, shows evidence of edge scattering in the equatorial direction at very low q (see Fig.…”

“…Data from SAXS studies of PE using in situ tensile deformation show a high degree of similarity to those observed here. [73][74][75] Indeed, additional analysis of the PUBIP SAXS data at high elongations, where the PTMO has crystallized, shows evidence of edge scattering in the equatorial direction at very low q (see Fig. S8).…”

Structure Evolution and Deformation Behavior of Polyethylene Film during Biaxial Stretching

“…Furthermore, the crystallinity ( X DSC ) is computed according to the following equation where Δ H m is the melting enthalpy, and Δ H m 0 is the melting enthalpy of 100% crystalline PE (287.3 J/g) . Moreover, the distribution of short-chain branching (SCB) for the ethylene/α-olefin copolymer was tested by the method of successive self-nucleation and annealing (SSA) fractionation, and the thermal procedures are shown in Figure S2a. , …”

“…28 Moreover, the distribution of short-chain branching (SCB) for the ethylene/ α-olefin copolymer was tested by the method of successive selfnucleation and annealing (SSA) fractionation, and the thermal procedures are shown in Figure S2a. 29,30 2.6. Fourier Transform Infrared Spectroscopy (FTIR).…”

Customizing superior surface insulation properties of polymeric dielectric via in-plane molecular chain orientation

“…The DSC curves in figure 2(m) shows that there is no crystal transition before and after stretching, but only an increase in crystallinity and melting temperature, which corresponds to the thickening of the lamellar. According to the 1D SAXS profiles and DSC curves, lamellar thickness (L c ) and amorphous thickness (L a ) can be obtained from the following equations [23,24],…”