1 research outputs found
Poly(butylene 2,5-furan dicarboxylate), a Biobased Alternative to PBT: Synthesis, Physical Properties, and Crystal Structure
This paper describes the synthesis, crystal structure,
and physicomechanical
properties of a biobased polyester prepared from 2,5-furandicarboxylic
acid (FDCA) and 1,4-butanediol. Melt-polycondensation experiments
were conducted by a two-stage polymerization using titanium tetraisopropoxide
(TiÂ[OiPr]<sub>4</sub>) as a catalyst. Polymerization conditions (catalyst
concentration, reaction time and second stage reaction temperature)
were varied to optimize polyÂ(butylene-FDCA), PBF, and molecular weight.
A series of PBFs with different <i>M</i><sub>w</sub> were
characterized by DSC, TGA, DMTA, X-ray diffraction and tensile testing.
Influence of molecular weight and melting/crystallization enthalpy
on PBF material tensile properties was explored. Cold-drawing tensile
tests at room temperature for PBF with <i>M</i><sub>w</sub> 16K to 27K showed a brittle-to-ductile transition. When <i>M</i><sub>w</sub> reaches 38K, the Young modulus of PBF remains
above 900 MPa, and the elongation at break increases to above 1000%.
The mechanical properties, thermal properties and crystal structures
of PBF were similar to petroleum derived polyÂ(butylenes-terephthalate),
PBT. Fiber diagrams of uniaxially stretched PBF films were collected,
indexed, and the unit cell was determined as triclinic (<i>a</i> = 4.78(3) Å, <i>b</i> = 6.03(5) Å, <i>c</i> = 12.3(1) Å, α = 110.1(2)°, β = 121.1(3)°,
γ = 100.6(2)°). A crystal structure was derived from this
data and final atomic coordinates are reported. We concluded that
there is a close similarity of the PBF structure to PBT α- and
β-forms