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Crystal structure and thermodynamic parameters of Nylon‐1010
Author(s) -
Zhishen Mo,
Qingbo Meng,
Jinhua Feng,
Hongfang Zhang,
Donglin Chen
Publication year - 1993
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.4990320110
Subject(s) - crystallinity , materials science , lamellar structure , amorphous solid , enthalpy of fusion , crystallography , triclinic crystal system , small angle x ray scattering , crystal (programming language) , crystal structure , electron density , lattice constant , recrystallization (geology) , analytical chemistry (journal) , melting point , diffraction , scattering , chemistry , composite material , electron , optics , organic chemistry , paleontology , biology , programming language , physics , quantum mechanics , computer science
WAXD, SAXS, FTIR, DSC and density techniques have been used to investigate the crystal structure, crystal density ρ c , amorphous density p a equilibrium heat of fusion δ H ° m and equilibrium melting temperature T ° m . By extrapolating the straight lines in the FTIR absorbance against density plot to zero intensity. ρ c and ρ a were estimated to be 1.098 and 1.003 g/cm 3 respectively. The ρ c obtained was too low in value. From X‐ray diffraction patterns of uniaxially oriented fibres, the crystal structure of Nylon‐1010 was determined. The Nylon‐1010 crystallized in the triclinic system, with lattice dimensions: a = 4.9 Å, b = 5.4 Å, c = 27.8 Å, α = 49°, β = 77°, γ = 63.5°. The unit cell contained one monomeric unit, the space group was P 1 , and the correct value of ρ c was 1.135 g/cm 3 . The degree of crystallinity of the polymer was determined as about 60% (at RT) using Ruland's method. SAXS has been used to investigate the crystalline lamellar thickness, long period, transition zone, the specific inner surface and the electron density difference between the crystalline and amorphous regions for Nylon‐1010. The analysis of data was based upon a one‐dimensional electron‐density correlation function. δ H ° m was estimated to be 244.0 J/g by extrapolation of δ H ° m in the plot of heat of fusion against specific volume of semicrystalline specimens to the completely crystalline condition ( V sp c= 1/ρ c ). Owing to the ease of recrystallization of melt‐crystallized Nylon‐1010 specimens, the well‐known Hoffman's T m ‐ T c method failed in determining T ° m and a Kamide double extrapolation method was adopted. The T ° m value so obtained was 487 K.