Composite separators are prepared by introducing SiO₂ nanoparticles on both sides of polypropylene separator with various SiO₂ contents through a dip-coating process, where polyvinylidene fluoride-hexafluoropropylene is used as binder. Coated layers have highly porous structure, which is quantitatively analyzed by air permeability. Compared to pristine separator, composite separators show significant lower Gurley value, reduced thermal shrinkage, higher liquid electrolyte uptake, better mechanical properties, and better cell performance such as discharge C-rate capability and cycle performance. The influence of SiO₂ content on these properties is also studied, and the best SiO₂ content is given. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41156.

Attapulgite (ATP)-reinforced poly(butylene succinate-co-1,2-octanediol succinate) nanocomposites were fabricated using an in situ two-step polymerization method. The transmission electron microscopy (TEM) results showed a superior interfacial linkage between ATP and PBS matrix. The isothermal crystallization kinetics results showed that ATP can effectively act as a nucleating agent, resulting in an enhancement on the crystallization temperature and crystallization rate. The incorporation of ATP nanoparticles probably induced heterogeneous nucleation that made the lower activation energy. The equilibrium melting temperature ( ) of the ATP reinforced branched copolymer also had little difference with the homogeneous PBS. The temperature at an initial thermal degradation was improved for the ATP reinforced branched nanocomposites. The dynamic mechanical analysis (DMA) results showed that there was a significant increase of storage modulus (E′) in an overall temperature range of all ATP reinforced nanocomposites. ATP had a strong effect on the elastic properties of the homogeneous PBS matrix. POLYM. COMPOS., 34:1126–1135, 2013. © 2013 Society of Plastics Engineers

Long-chain branched poly(butylene succinate) were synthesized through a two-step process of esterification and polycondensation, using 1,2,4-butanetriol (1,2,4-BT) as a long-chain branching agent. The effect of long-chain branches on the crystallization behaviors, rheological properties, and tensile properties was investigated systematically. The results of differential scanning calorimetry and polarized optical microscopy showed that with the increasing of 1,2,4-BT segments, the crystallization temperatures and glass transition temperatures increase slightly, while the relative crystallinity degree decreases gradually. Also, the double-banded extinction patterns with periodic distance along the radial direction were observed in the spherulites of long-chain branched poly(butylene succinate), similar to that of linear poly(butylene succinate) (PBS). The result of wide-angle X-ray diffraction indicated that the incorporation of 1,2,4-BT segments had little effect on the crystal structure of PBS. However, based on data from rheology and tensile testing, the viscoelastic properties of long-chain branched PBS under shear flow were different from the linear PBS. For example, the complex viscosities, storage modulus, and loss modulus of long-chain branched PBS at low frequency were significantly enhanced in comparison with those of linear PBS. In addition, long-chain branched PBS showed higher tensile strength than that of linear PBS without notable decrease in the elongation at break when compared with linear PBS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Poly(butylene succinate) (PBS)/pristine raw multiwalled carbon nanotube (MWCNT) composites were prepared in this work via simple melt compounding. Morphological observations indicated that the MWCNTs were well dispersed in the PBS matrix. Moreover, the incorporation of MWCNTs did not affect the crystal form of PBS as measured by wide-angle X-ray diffraction. The rheology, crystallization behaviors, and thermal stabilities of PBS/MWCNT composites were studied in detail. Compared with neat PBS, the incorporation of MWCNTs into the matrix led to higher complex viscosities (|η*|), storage modulus (G′), loss modulus (G″), shear thinning behaviors, and lower damping factor (tan δ) at low frequency range, and shifted the PBS/MWCNT composites from liquid-like to solid-like, which affected the crystallization behaviors and thermal stabilities of PBS. The presence of a very small quantity of MWCNTs had a significant heterogeneous-nucleation effect on the crystallization of PBS, resulting in the enhancement of crystallization temperature, i.e., with the addition of 0.5 wt % MWCNTs, the values of T_c of PBS/MWCNT composites could attain to 90°C, about 6°C higher than that of neat PBS, whereas the values of T_c increased slightly with further increasing the MWCNTs content. The thermogravimetric analysis illustrated that the thermal stability of PBS was improved with the addition of MWCNTs compared with that of neat PBS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Branched poly(butylene succinate) (PBS) copolymers were synthesized, from succinic acid (SA), 1,4-butanediol (1,4-BD), and 1,2-octanediol (1,2-OD) through a two-step process containing esterification and polycondensation, with different mole fractions of 1,2-OD segments. The branched PBS copolymers were characterized with ¹H-NMR, differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA), dynamic rheological testing, and tensile properties analysis. The results of DSC and WAXD show that, with the increasing of the 1,2-OD segments content, the glass transition temperature (T_g), melting temperature (T_m), crystallization temperature (T_c), and the degree of crystallinity (X_c) decrease. While the crystal structure of PBS does not change by introducing 1,2-OD segments. The results of TGA and dynamic rheological testing indicate that the thermal stability of neat PBS is improved with the addition of 1,2-OD segments. The incorporation of 1,2-OD segments has some effects on the rheological properties of PBS, such as complex viscosities (|η*|), storage modulus (G′), and loss modulus (G″). Tensile testing demonstrates that the elongation at break is improved significantly with increasing 1,2-OD segments content, but without a notable decrease of tensile strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Lamellar single crystals of poly(butylene succinate) (PBS) with novel morphologies were prepared from a chloroform/methanol solution by self-seeding methods. Crystal structures and morphologies were investigated by means of atomic force microscopy (AFM). Lath-shaped crystal and hexagonal-shaped crystals coexist in one PBS single crystal and this has a lamellar thickness of around 5–6 nm as determined by AFM. The thickening of lamellae from 5–6 to 7–9 nm occurred during heating from 41 to 84 °C. In situ temperature-controlled AFM observations demonstrated that the lath-shaped crystal sections melted first and then the hexagonal sections while the edge of the single crystals remained regular during annealing. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1492–1496, 2009