The Effect of Sterilization Methods on Plastics and Elastomers

Liesl K. Massey

• Publisher: William Andrew
• Year: 2004
• Print ISBN: 9780815515050
• eBook ISBN: 9780815519232
• Edition: 2
• Topic: Tecnologia e ingegneria
• Subtopic: Scienza dei materiali

This extensively updated second edition was created for medical device, medical packaging, and food packaging design engineers, material product technical support, and research/development personnel. This comprehensive databook contains important characteristics and properties data on the effects of sterilization methods on plastics and elastomers. It provides a ready reference for comparing materials in the same family as well as materials in different families. Data is presented on 43 major plastic and elastomer packaging materials, including biodegradable or organic polymers. New to this edition are resin chapters containing textual summary information including: category; general description; applications; resistances to particular sterilization methods; and regulatory status considerations for use in medical devices and medical/food packaging. The resin chapter material supplier trade name product data is presented in graphical and tabular format, with results normalized to SI units, retaining the familiar format of the best selling first edition and allowing easy comparison between materials and test conditions.

Glossary of Terms

A

ABS: See Acrylonitrile Butadiene Styrene Polymer.

ABS PC Alloy: See Acrylonitrile Butadiene Styrene Polymer Polycarbonate Alloy.

ABS Resin: See Acrylonitrile Butadiene Styrene Polymer.

Acetal Resins: Thermoplastics prepared by polymerization of formaldehyde or its trioxane trimer. Acetals have high impact strength and stiffness, low friction coefficient and permeability, good dimensional stability and dielectric properties, and high fatigue strength and thermal stability. Acetals have poor acid and UV resistance and are flammable. Processed by injection and blow-molding and extrusion. Used in mechanical parts such as gears and bearings, automotive components, appliances, and plumbing and electronic applications. Also called acetals.

Acetals: See Acetal Resins.

Acrylic Resins: Thermoplastic polymers of alkyl acrylates such as methyl methacrylates. Acrylic resins have good optical clarity, weatherability, surface hardness, chemical resistance, rigidity, impact strength, and dimensional stability. They have poor solvent resistance, poor resistance to stress cracking and poor flexibility, and thermal stability. Processed by casting, extrusion, injection molding, and thermoforming. Used in transparent parts, auto trim, household items, light fixtures, and medical devices. Also called polyacrylates.

Acrylonitrile Butadiene Styrene (ABS) Polymer: ABS resins are thermoplastics comprised of a mixture of styrene-acrylonitrile copolymer (SAN) and SAN-grafted butadiene rubber. They have high impact resistance, toughness, rigidity, and processability, but low dielectric strength, continuous service temperature, and elongation. Outdoor use requires protective coatings in some cases. Plating grades provide excellent adhesion to metals. Processed by extrusion, blow-molding, thermoforming, calendaring, and injection molding. Used in household appliances, tools, nonfood packaging, business machinery, interior automotive parts, extruded sheet, pipe, and pipe fittings. Also called ABS, ABS resin, and acrylonitrile butadiene styrene polymer.

Acrylonitrile Copolymer: A thermoplastic prepared by copolymerization of acrylonitrile with small amounts of other unsaturated monomers. Has good gas barrier properties and chemical resistance. Processed by extrusion, injection molding, and thermoforming. Used in food packaging.

Alcohols: A class of hydroxy compounds in which a hydroxy group(s) is attached to a carbon chain or ring. Alcohols are produced synthetically from petroleum stock, e.g., by hydration of ethylene, or derived from natural products, e.g., by fermentation of grain. The alcohols are divided in the following groups: monohydric, dihydric, trihydric, and polyhydric. Used in organic synthesis, and as solvents, plasticizers, fuels, beverages, and detergents, etc.

Amorphous Nylon: Transparent aromatic polyamide thermoplastics. Produced by condensation of hexamethylene diamine, isophthalic and terephthalic acid.

Antioxidant: A chemical substance capable of inhibiting oxidation or oxidative degradation of another substance such as plastic in which it is incorporated. Antioxidants act by terminating chain-propagating free radicals or by decomposing peroxides, formed during oxidation, into stable products. The first group of antioxidants include hindered phenols and amines; the second group includes sulfur compounds, such as thiols.

Aromatic: A major group of unsaturated cyclic hydrocarbons containing one or more rings (e.g., benzene) or by chemical behavior similar to benzene. The benzene ring is characterized by three double bonds alternating with single bonds between carbon atoms. Aromatics readily undergo electrophylic substitution; that is, they react to add other active molecular groups, such as nitrates, sulfonates, etc. Aromatics are used extensively as petrochemical building blocks in the manufacture of pharmaceuticals, dyes, plastics, and many other chemicals.

ASTM International: Formerly known as the American Society for Testing and Materials.

ASTM D256: Standard Test Methods for Determining the Izod Pendulum Impact Resistance of Plastics. Used to determine the resistance of a plastic specimen to impact by a pendulum-type hammer. Specimens contain a milled notch and depending upon the test method, failure may be brittle or ductile. Test results are reported in terms of energy absorbed per unit of specimen width or per unit of cross-sectional area under the notch.

ASTM D638: Standard Test Method for Tensile Properties of Plastics is used to determine the tensile properties of unreinforced and reinforced plastics under defined conditions of pretreatment, temperature, humidity, and testing machine speed. Specimens are dumbbell-shaped and can be of any thickness up to 14 mm. However, Test Method D882 is the preferred test method for testing films less than 1.0 mm. Materials with a thickness greater than 14 mm (0.55 in.) must be reduced by machining. D638 also includes the option of determining Poisson’s ratio at room temperature. This test method and ISO 527-1 are technically equivalent.

ASTM D882: Standard Test Method for Tensile Properties of Thin Plastic Sheeting. Used to determine tensile properties of plastics in the form of thin sheeting, including film having a nominal thickness not greater than 0.25 mm (0.010 in.). In D882, specimen extension may be measured by grip separation, extension indicators, or displacement of guage marks. This test method is similar to ISO 527-3, but is not considered technically equivalent.

ASTM D3763: The High Speed Impact Standard Test Method is used to determine toughness, load-deflection curves and total energy absorption of impact events.

Atmosphere: A metric unit of measurement of pressure equal to 1.013250 × 10⁶ dynes/cm² or 1.013250 x 10⁵ pascals, which is the air pressure measured at mean sea level. It has a dimension of unit of force per unit of area. Used to denote the pressure of gases, vapors, and liquids. Also called atm, standard atmosphere, and std atm.

Autoclave Sterilization: Sterilization by steam under pressure in an autoclave. Also called Steam Sterilization.

B

Bar: A metric unit of measure of pressure equal to 10⁶ dynes/cm² or 10⁵ pascals. It has a dimension of unit of force per unit of area. Used to denote the pressure of gases, vapors, and liquids.

Barrier Material: Materials such as plastic films, sheeting, wood laminates, particle board, paper, fabrics, etc., with low permeability to gases and vapors. Used in construction as water vapor insulation, food packaging, and protective clothing, etc.

Benzene: An aromatic hydrocarbon with a six-atom carbon ring, C₆H₆. Highly toxic and flammable (autoignition point: 562°C). A colorless or yellowish liquid under normal conditions (b.p.80.1°C), soluble in many organic solvents such as ethanol, aceton...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• Introduction to Sterilization Methods
• Acetal Resins
• ABS
• Acrylic Resins
• Fluoroplastic
• Polyphenylene
• Nylon
• Polycarbonate
• Polyester
• Polyketone
• Polyolefin
• Polypropylene
• Polyphenylene Sulfide
• Polystyrene
• Polysulfone
• Polyurethane
• Styrene Acrylonitrile
• Styrene Butadience Copolymer
• Vinyl Resin
• Thermoplastic Alloy
• Thermoplastic Elastomer
• Silicone Rubber
• Additional Materials
• Indices and Appendices
• Endnotes to Tables
• Glossary of Terms
• Trade Name Index
• References