Bead foam microstructure and processing

Pentane

Bead foam microstructure and processing

by Manufacturers, Producers, Suppliers Feb 9, 2021

Pentane, n-

PARAMETER	UNIT	VALUE
GENERAL INFORMATION
Name	Pentane, n-
CAS #	–	109-66-0
IUPAC name	pentane
Common name	amyl hydride
Empirical formula	–	C5H12
Formula	CH₃(CH₂)₃CH₃
Molecular mass	daltons	72.17
RTECS number	–	RZ9450000
Chemical category	aliphatic hydrocarbon
EC number	–	203-692-4
Product contents	n-pentane, 95-100 wt%
PHYSICAL PROPERTIES
State	–	L
Odor	–	gasoline-like
Odor threshold	ppm	400
Color	–	colorless
Boiling point	°C	36.1
Freezing point	°C	−129.73
Refractive index at 20°C	–	1.3580
Specific gravity	g cm⁻³	0.630
Specific gravity temperature	°C	15.6
Vapor density	air=1	2.50
Vapor pressure	kPa	68.3
Vapor pressure temperature	°C	25
Evaporation rate	butyl acetate=1	12.0
Evaporation rate	ether=1	1.0
Enthalpy of vaporization	kJ mol⁻¹	25.79
Enthalpy of vaporization temperature	K	309.2
Polarity parameter, E_T(30)	kcal mol⁻¹	31.1
Corrosivity	–	N
Molar volume	cm³ mol⁻¹	116.0
Kauri butanol number	–	26.0
Coefficients of Antoine equation	coefficient A	3.9892
	coefficient B	1070.617
	coefficient C	−40.454
Temperature range of Antoine equation	°C	268.7 to 341.4
pH	–
Viscosity	mPas (cP)	0.225
Viscosity temperature	°C	25
Surface tension at 20°C	mN m⁻¹	15.48
Solubility in water at 20°C	mg kg⁻¹	39
Heat of combustion at 25°C	MJ kg⁻¹	48.81
Specific heat at 25°C	kJ K⁻¹ mol⁻¹	167.19
Thermal conductivity at 25°C	W m⁻¹ K⁻¹	0.12
Coefficient of thermal expansion	10⁻⁴ °C⁻¹ (K⁻¹)	10.0
Hildebrand solubility parameter	(MPa)^1/2	14.36
Hansen solubility parameters, (MPa)^1/2	dD	14.5
	dP	0.0
	dH	0.0
Henry’s law constant	atm/m³-mol⁻¹	1.27E+00
Relative permittivity	–	1.84
Electrical conductivity	pS m⁻¹	1.1
HEALTH & SAFETY
NFPA classification	Flammability	4
	Health	1
	Reactivity	0
UN risk phrases, R	R12,R51/53,R65,R66,R67
US safety phrases, S	S9,S16,S29,S33,S61,S62
UN number	–	1265
UN/NA hazard class	3
UN packaging group	II
DOT class	UN 1265 PENTANES, 3, II
TDG class	3, II
ICAO/IATA class, packaging group	UN 1265 PENTANES, 3, II
IMDG class, packaging group	UN 1265 PENTANES, 3, II (<−40°C), Marine Pollutany, (N-Pentane)
Proper shipping name	pentanes
Autoignition temperature	°C	243
Flash point	°C	<−40
Flash point method	–	TOC
Explosion limit, lower	wt%	1.42
Explosion limit, upper	wt%	7.80
Threshold limiting value – TWA 8h, ACGIH	mg m⁻³	1770
Threshold limiting value – TWA 8h, ACGIH	ppm	600
Threshold limiting value – TWA 8h, NIOSH	mg m⁻³	350
Threshold limiting value – TWA 8h, NIOSH	ppm	120
Maximum exposure concentration NIOSH-IDLH	mg m⁻³	45000
Maximum exposure concentration NIOSH-IDLH	ppm	1500
Maximum concentration, any time, ACGIH	ppm	600
Maximum concentration, any time, NIOSH	mg m⁻³	1800
Maximum concentration, any time, NIOSH	ppm	610
Maximum concentration, any time, OSHA	mg m⁻³	1800
Maximum concentration, any time, OSHA	ppm	600
Maximum concentration, 15 min., ACGIH	mg m⁻³	2210
Maximum concentration, 15 min., ACGIH	ppm	750
Maximum concentration, 15 min., NIOSH	mg m⁻³	1800
Maximum concentration, 15 min., NIOSH	ppm	610
Maximum concentration, 15 min., OSHA	mg m⁻³	2950
Maximum concentration, 15 min., OSHA	ppm	1000
Animal testing, acute toxicity, Rat oral LD50	mg kg⁻¹	2000
Animal testing, acute toxicity, Rat inhalation, LC50	ppm	110000/2H mus
Route of entry	Inh, Ing, Con
Ingestion	Harmful if swallowed may cause lung damage.
Skin irritation	Repeated exposure may cause skin dryness or cracking.
Eye irritation	May cause eye irritation.
Inhalation	Inhalation vapors may cause drowsiness and dizziness.
First aid: eyes	Flush eyes with water while holding eyelids open. Rest eyes for 30 minutes. If redness, burning, blurred vision, or swelling persist, transport to the nearest medical facility for additional treatment
First aid: skin	Remove contaminated clothing. Flush exposed area with water and follow by washing with soap if available.
First aid: inhalation	Remove to fresh air. If rapid recovery does not occur, transport to nearest medical facility for additional treatment.
Target organs	RspSys,Eye,Skin,CNS,Kdny
Carcinogenicity IARC	N
Carcinogenicity NTP	N
Carcinogenicity OSHA	N
Mutagenic properties	N
ECOLOGICAL PROPERTIES
Aquatic toxicity, Daphnia magna, 48-h LC50	mg l⁻¹	2.7
Aquatic toxicity, Rainbow trout, 96-h LC50	mg l⁻¹	4.3
Theoretical oxygen demand	g g⁻¹	3.56
Bioconcentration factor	–	2.35
Biodegradation probability	–	days
Hydroxyl rate constant	cm³ molecule⁻¹ s⁻¹	3.94E-12
Montreal protocol	–	N
Partition coefficient	logK_ow	3.39
Urban ozone formation potential	C₂H₄=1	0.11
Soil absorption constant	–	1.91
UV absorption	nm	<195
USE & PERFORMANCE
Manufacturer	–	generic

Pentane is introduced to suspension-polymerised polystyrene (PS) beads. Molecular weights in the range of 150,000–250,000 are used. The spherical beads are sieved to a narrow range of diameters, so are not monodisperse. PS beads are allowed to absorb up to 8% by weight of pentane, which is a plasticiser, reducing the glass transition temperature from 100°C to about 60°C . Cigna et al. (1986) used an ultramicrotome to section the pentane-containing beads, and then transmission electron microscopy. Microvoids within them are the sites of the later cell expansion. The surfaces of the beads are coated, typically with less than 0.5% of calcium stearate, to prevent agglomeration.

Expanded polypropylene (EPP) goes through a process of extrusion foaming as small diameter rod, then pelletised into beads, much as most thermoplastics are pelletised prior to injection moulding. Hence the initial production is as described in the last chapter, and high melt strength polypropylene (PP) grades must be used. The blowing agent is probably isopentane or CO₂. Some of the beads have a solid PP outer layer, and their average density is lower than the final EPP mouldings (Beverte, 2004), a disadvantage compared with EPS in that bulky material must be transported to the site of moulding.

Resin and Asphaltene Gravimetric Determination
A 100 mL quantity of n-pentane is added to a pre-weighed sample of approximately 5 g of oil. The flask is shaken well and allowed to stand for 30 min [27,28]. The sample is filtered through a 0.45-μm membrane using minimum rinsing with n-pentane. The precipitate is allowed to dry and then weighed. The weight of the precipitate as a fraction of the initial oil sample weight is reported as the percentage asphaltenes.

The filtrate from the precipitation, the “maltene” fraction, is recovered and made up to 100 mL with n-pentane. A 15-g, 1-cm diameter column of activated silica gel is prepared. The top of the column is protected by a 1-cm layer of sodium sulfate. A 5-mL aliquot of the maltene fraction is loaded onto the column. A 60-mL volume of 1:1 (v:v) benzene:hexane is eluted through the column and discarded. A 60-mL volume of methanol, followed by a 60-mL volume of dichloromethane is eluted through the column and combined. The methanol/dichloromethane fractions are reduced by rotary evaporation and blown down to dryness under nitrogen. The mass fraction of this dried eluent, compensating for the volume fraction used, is reported as the percentage of resins in the sample.

Bead foam microstructure and processing

Pentane, n-

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