Solid phase
Official name
FULL solid
Secondary names
polyethylene; polyethene; poly(methylene); PE
CAS number
9002-88-4
Family
molecular solid
Class
non polar molecular solid
Compound type
homopolymer
Comments
The polymer has up to 7 500 000 monomers units and different branching degrees. It is classified according to its density and branching: very-low-density polyethylene (VLDPE), low-density polyethylene (LDPE), Linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), Cross-linked polyethylene (PEX or XLPE), High-density cross-linked polyethylene (HDXLPE), high-density polyethylene (HDPE), Ultra-low-molecular-weight polyethylene (ULMWPE or PE-WAX), High-molecular-weight polyethylene (HMWPE), and ultra-high-molecular-weight polyethylene (UHMWPE)
Terminal function
$CH_3$
Monomer number
n, up to 7500000
Molar mass
28.053 per mer unit $g/mol$
Polymolecularity index
1
Crystallinity degree
0.55
Comments
no well crytallized
Formula
$CH_3-(CH_2-CH_2)_n-CH_3$
Chemical formula
(CH3)2(C2H4)n
Elemental formula
(2H)10-404 (H)14-604 (Vo)10-500
Isotope mixture type
partly substituted
108.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
L-$(COOH)CH_2CHOH(COOH)$ FULL molecule molecule 2 - 100 0.9444444444444444 $\pm$ 0.9074074074074074 1.0 pure main
$^2H$ or $D$ Full Isotope element 2 - 4 0.027777777777777776 $\pm$ 0.009259259259259259 0.5 clathrate network substituted
$H$ Full Natural element 2 - 4 0.027777777777777776 $\pm$ 0.009259259259259259 0.5 clathrate network substituted
Composition comments
The formula is n repeting units + 2 $-CH_3$ terminal functions
Chemical functions
  Function Number
$R-CH2-OH$ 2
$R-C(=O)-R$ 3
$R-CH2-OH$ 3
$R-C(=O)-R$ 1
R-V=R 2
Chemical bonds
  Bond Number
$-C \leq H_3$ n+1
$=C=O$ 6
$-C \leq H_3$ 3
$=C=O$ 2
>V=V< 1
Oxides
Formula $Sm_{2}O_{3}$ $Co_{3}O_{4}$ $F$
Mass fraction (%) 25.0 35.0 40.0
Oxides comments
très oxydé
Class
molecular solids with apolar molecules (01)
Type
with polyatomic organic apolar molecules (CnHm...) (01.06)
Group
H2O polymorphs (03.01.01)
Code
04.01.01.05’
Endmembers
Polymorphs
Equivalent liquid
FULL Liquid water
Equivalent mineral
FULL Mineral
Phase name
Full
Phase type
various
Crystal system
N/A
Crystal class
ditetragonal-dipyramidal
Crystal class symbol
-43m (Td)
Crystal spacegroup
P4(2)/nnm
Polytypes
  • Very-low-density polyethylene (VLDPE) (VLDPE is defined by a density range of 0.880–0.915 g/cm3. VLDPE is a substantially linear polymer with high levels of short-chain branches.)
  • Low-density polyethylene (LDPE) (LDPE is defined by a density range of 0.910–0.940 g/cm3. LDPE has a high degree of short- and long-chain branching.)
Crystal sites
Label Type Nb Wp Species Species coordinence Species occupancy Species oxidation state
M1 split interstitial 2 1e222  $^2H$ or $D$ tetrahedral IV 0.75 2
 $H$ bicapped hexagonal antiprismatic XIV 0.25 2
O4 interstitial 3 1e222  $^2H$ or $D$ trigonal prismatic VI 0.48 3
 $H$ trigonal bipyramidal V 0.0 0
Crystal molecule sites
Label Type Nb Species Species coordinence Species occupancy Species order
cage 5-12_6-4 split interstitial 2  L-$(COOH)CH_2CHOH(COOH)$ pentagonal dodecahedron XX 0.25 fixed position
 R-$(COOH)_2CHOSF2$ hexagonal truncated trapezohedron XXIV 0.75 orientationaly disordered
cage 5-12_6-8 topological defect 6  L-$(COOH)CH_2CHOH(COOH)$ hexadecahedron XXVIII 0.33 unknown
 R-$(COOH)_2CHOSF2$ trigonal prismatic square face bicapped VIII 0.66 rotating
Composition order
partly ordered
Comments
crystal comments
Molar mass
28.053 $g/mol$
Density
0.87 - 0.97 $g/cm^3$
State NTP
solid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-liquid decomposition glass polyethylene ~160-200 K (~ -70°C - -110°C)
triple point solid-solid-liquid amorphous Water ice Ia ~160-200 K (~ -110°C - -180°C)
Phase transitions comments
above the glass transition melting occurs at 45-144°C
Refringence type
biaxial
Refringence sign
positive or negative
Birefringence
1 - 2.5
Refraction index $n_{\alpha}$
1.475 - 1.54
Refraction index $n_{\beta}$
1.475 - 1.54
Refraction index $n_{\gamma}$
1.475 - 1.54
Dispersion V
strong
Pure color
colorless, white
Color
various
Diaphaneity
transparent to opaque
Luster
vitreous