1、Designation: D 788 06Standard Classification System forPoly(Methyl Methacrylate) (PMMA) Molding and ExtrusionCompounds1This standard is issued under the fixed designation D 788; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 The purpose of this classification system is to provide amethod of adequately identifying PMMA materials usin
3、g asystem consistent with that of Classification System D 4000.Itfurther provides a means for specifying these materials by theuse of a simple line callout designation.1.2 This classification system covers poly(methyl methacry-late) molding and extrusion compounds. These compounds arepolymers based
4、on methyl methacrylate, and at least 70 % ofthe polymer shall be polymerized from methyl methacrylate.1.3 The properties in this classification system are thoserequired to identify the compositions covered. There may beother requirements necessary to identify particular character-istics important to
5、 specific applications. These shall be de-scribed by using the suffixes as given in Section 5.1.4 Acrylic molding and extrusion compounds are usedfrequently in applications where extreme clarity and the abilityto retain that clarity and color under severe weathering andother environmental exposures
6、are of primary significance.While the test specimen properties of this document may beused to evaluate nonvirgin materials, the user should takeprecautions to ensure that parts made from these materials meetthe desired end-use requirements. Accordingly, this specifica-tion allows for the use of thos
7、e acrylic plastic materials that canbe recycled, reconstituted, and regrounded provided the fol-lowing:1.4.1 The requirements as stated in this specification aremet,1.4.2 The material has not been modified in any way to alterits conformance to food contact regulations or similar require-ments, and1.
8、4.3 The requirements of the particular end-use applicationare met.1.5 This classification system and subsequent line callout(specification) are not intended for the selection of materials,but only as a means to call out plastic materials to be used forthe manufacture of parts. The selection of these
9、 materials is tobe made by personnel with expertise in the plastics field inwhich the environment, inherent properties of the materials,performance of the parts, part design, manufacturing process,and economics are considered.NOTE 1This classification system is similar to ISO 8257-1:1987 intitle onl
10、y. The technical content is significantly different.1.6 The values stated in SI units are to be regarded asstandard.1.7 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate
11、 safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD 150 Test
12、Methods for AC Loss Characteristics and Per-mittivity (Dielectric Constant) of Solid Electrical Insula-tionD 257 Test Methods for DC Resistance or Conductance ofInsulating MaterialsD 618 Practice for Conditioning Plastics for TestingD 883 Terminology Relating to PlasticsD 1003 Test Method for Haze a
13、nd Luminous Transmittanceof Transparent PlasticsD 1238 Test Method for Melt Flow Rates of Thermoplasticsby Extrusion PlastometerD 1600 Terminology for Abbreviated Terms Relating toPlasticsD 3641 Practice for Injection Molding Test Specimens ofThermoplastic Molding and Extrusion MaterialsD 3892 Pract
14、ice for Packaging/Packing of PlasticsD 4000 Classification System for Specifying Plastic Mate-rials1This classification system is under the jurisdiction ofASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials (Section D20.15.02).Current editi
15、on approved Sept. 1, 2006. Published September 2006. Originallyapproved in 1944. Last previous edition approved in 2005 as D 788 - 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume info
16、rmation, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E29 Practice for Using Significant Digits in T
17、est Data toDetermine Conformance with Specifications2.2 ISO Standards and Recommendations:3ISO 179 PlasticsDetermination of Charpy ImpactPropertiesPart 1: Non-Instrumented Impact TestISO 294 PlasticsInjection Moulding of Test Specimens ofThermoplastic MaterialsPart 1: General Principles, andMoulding
18、 of Multipurpose and Bar Test SpecimensISO 306 PlasticsThermoplastic MaterialsDetermination of Vicat Softening TemperatureISO 489 PlasticsDetermination of the Refractive Index ofTransparent PlasticsISO 527 PlasticsDetermination of Tensile PropertiesISO 1133 PlasticsDetermination of the Melt Flow Rat
19、e ofThermoplasticsISO 3167 PlasticsPreparation and Use of MultipurposeTest SpecimensISO 8257-1 PlasticsPoly(Methyl Methacrylate) (PMMA)Moulding and Extrusion MaterialsPart 12.3 SAE Standards:4SAE J576 SEP86SAE Recommended Practice for PlasticMaterials for Use in Optical Parts such as Lenses andRefle
20、ctors for Motor Vehicle Lighting DevicesSAE J1885 AUG87SAE Recommended Practice for Ac-celerated Exposure of Automotive Interior Trim Compo-nents Using a Controlled Irradiance Water Cooled XenonArc ApparatusSAE J1960 JUN89SAE Standard for Accelerated Expo-sure of Automotive Exterior Materials Using
21、a ControlledIrradiance Water Cooled Xenon Arc Apparatus3. Terminology3.1 DefinitionsThe terminology used in this classificationsystem is in accordance with Terminologies D 883 and D 1600.4. Basis of Classification4.1 Poly(methyl methacrylate) molding and extrusion com-pounds are classified into grou
22、ps in accordance with theircomposition. These groups are subdivided into classes andgrades as shown in Table 3. A complete classification mustinclude reference to melt-flow rate, as discussed in 4.2 and5.1.4.4.1.1 To facilitate the incorporation of future or specialmaterials, the “other/unspecified”
23、 category (0) for group, class,and grade is given in Table 3.4.1.2 When the grade of the basic material is not shown, oris not important, the use of “0” grade classification shall beused in this classification system.4.2 The melt-flow rate can vary within a given group, class,and grade and can overl
24、ap classes or grades. For this reason,the melt-flow rate shall be specified using Suffix V.4.2.1 Although the values listed in Suffix V are necessary toinclude the range of properties available in existing materials,users should not infer that every melt-flow rate exists for eachclass or grade.NOTE
25、2An example of this classification system is as follows:The designation PMMA0112 indicates:PMMA = poly(methyl methacrylate) as found in Terminology D 1600,01 = unmodified (group),1 = minimum 77C Vicat, etc. (class) and2 = ultraviolet transmitting (grade).(See Note 4 for a more complete example.)NOTE
26、 3Major industries using these materials now require interna-tionally accepted test methods for product specifications. For this reason,ISO test methods have been used in Table 3 and elsewhere in thisclassification system where appropriate. Similar ASTM standards havebeen listed in Section 2. Many o
27、f these ASTM standards are now or soonwill be equivalent. In future editions, a note in the ASTM standard willindicate the degree of equivalency with a particular international standard.The corresponding ASTM test method may be substituted as long as thespecimen size and all other conditions of the
28、test method noted in thisclassification system as applying to the ISO test method are also appliedto the ASTM standard.4.3 Grade 1 materials are used where special ultraviolettransmission, filtering, or stabilization characteristics are notrequired.4.4 Grade 2 materials are used for those specialize
29、d appli-cations in which the greatest amount of transmission of UVlight is required. The transmission properties are given in Table1.4.5 Grade 3 materials (transparent UV stabilized or trans-parent UV absorbing) are used when either special resistance toslight color change over long exposure times o
30、r high-intensityUV radiation is required, or when the material is required tofilter out ultraviolet light. These applications are varied andrequire specific light transmission or color-stability propertiesto be specified by the user.3Available from American National Standards Institute (ANSI), 25 W.
31、 43rd St.,4th Floor, New York, NY 10036.4Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001.TABLE 1 Transmission of Grade 2 Materials at VariousWavelengthsA,BWavelength, nm Transmission, min, %400 86340 85310 70290 50280 26270 12AMeasured with UV spe
32、ctrophotometer using an integrating sphere and asample thickness of 3.2 mm.BThese requirements are in addition to the luminous transmittance require-ments given in Table 3.TABLE 2 Electrical Properties of Unmodified PMMAPropertyTestMethodRequirementInsulation resistance, min, Mohm D 257 1 3 107Diele
33、ctric strength min, kV/mmAD 149 13.8Dielectric constant at 1 MHz, max D 150 4.5Dissipation factor at 1 MHz, max D 150 0.05AkV/mm 3 25.4 = V/mil.D7880625. Suffixes5.1 When additional requirements are needed, based on theapplication, that are not covered by the basic cell-table require-ments, they sha
34、ll be indicated through the use of suffixes. Ingeneral, suffixes consist of a suffix letter, which gives therequirement needed, a first digit, which gives the test condition,and a second digit, which gives the specific requirement.5.1.1 Suffix E = Electrical requirements, as designated bythe followi
35、ng digits:First Digit0 = to be specified by the user.1 = specimen thickness, 3.2 mm, nominal.Second Digit0 = to be specified by the user.1 = volume resistivity, dielectric constant, and dissipation factormeet property limits as given in Table 2.5.1.2 Suffix H = Heat-stability requirements, as design
36、atedby the following digits:TABLE 3 PMMA Poly(Methyl Methacrylate) Materials Detail RequirementsNoteThe values listed were developed for natural colors. Colorants or other additives, or both, may alter these properties.Group Description Class DescriptionAGrade DescriptionACharpyImpact,TestMethodISO
37、179BkJ/m2,minTensileStrength,TestMethodISO 527,CMPa, minLuminousTransmittance,Test MethodD 1003,D%, minHaze,TestMethodD 1003,D%, maxIndex ofRefraction,TestMethodISO 489DTensileModulus,TestMethodISO 527,CMPa, minVicatSofteningTemperature,Test MethodISO 306,EC, min01 UnmodifiedF1 Formerly 1 General pu
38、rpose . 58 90 2.5 1.48-1.50 2700 77Grade 5 2 UV transmittingG. 58 90 2.5 1.48-1.50 2700 77(D 788 - 84) 3 UV stabilizedH. 58 90 2.5 1.48-1.50 2700 772 Formerly 1 General purpose . 62 90 2.5 1.48-1.50 2700 86Grade 6 2 UV transmittingG. 62 90 2.5 1.48-1.50 2700 86(D 788 - 84) 3 UV stabilizedH. 62 90 2.
39、5 1.48-1.50 2700 863 Formerly 1 General purpose . 65 90 2.5 1.48-1.50 2700 95Grade 8 2 UV transmittingG. 65 90 2.5 1.48-1.50 2700 95(D 788 - 84) 3 UV stabilizedH. 65 90 2.5 1.48-1.50 2700 954 Higher VicatSofteningPoint thanFormerGrade 81 General purpose . 65 90 2.5 1.48-1.50 2700 1042 UV transmittin
40、gG. 65 90 2.5 1.48-1.50 2700 1043 UV stabilizedH. 65 90 2.5 1.48-1.50 2700 10402 Impact 1 1 1.2 51 88 4.0 1.48-1.50 2600 95modifiedI0 Other/unspecified. . . . . . .2 1 2.0 38 88 4.0 1.48-1.50 2500 903 1 4.3 31 88 4.0 1.48-1.50 1700 854 1 3.0 31 88 4.0 1.48-1.50 1700 8503 Heat-ResistancemodifiedJ1 1
41、General purpose . 65 90 2.5 1.48-1.50 2700 1132 UV transmittingG. 65 90 2.5 1.48-1.50 2700 1133 UV stabilizedH. 65 90 2.5 1.48-1.50 2700 1134 Impact modified also tbd 56 88 4.0 1.48-1.50 tbd 1132 1 General purpose . 65 90 2.5 1.48-1.50 2700 1222 UV transmittingG. 65 90 2.5 1.48-1.50 2700 1223 UV sta
42、bilizedH. 65 90 2.5 1.48-1.50 2700 12200 Other 0 0 Other/unspecified . . . . . . .ANo descriptions are listed unless needed to describe a special grade or class. All other categories are listed by requirements.BPreferred test specimens are 4 by 10 by 80 mm with a notch radius of 0.25 mm with 8-mm de
43、pth below notch (Type 1) and are tested by Method A. When necessary,to fit existing equipment, these specimens may be cut to 63.5-mm length. Annealing is neither required nor prohibited.CTest specimens are tensile bars with dimensions corresponding to the ISO 3167 multipurpose test specimen, tested
44、at a crosshead speed of 1 mm/min to obtain tensilemodulus. As an option, the crosshead speed is increased to 5mm/min to obtain the tensile strength value when the test specimen has reached a minimum of 0.3 %elongation. Annealing is neither required nor prohibited.DTest specimens are 3.2-mm thick of
45、colorless material.ETest specimens are 4-mm thick, tested at a rate of 50C/h and a load of 50 N. They are placed in a desiccator immediately after molding to prevent water pickup andkept dry until ready for test. Alternatively, they can be dried for 16 h at 80 6 3C and then cooled in a desiccator un
46、til ready for test.FUnmodified group materials are polymerized from 70 to 100 % methacrylate monomer and 0 to 30 % acrylic comonomers.GSee 4.4 for description.HSee 4.5 for description.IImpact-modified materials contain 50 to 95 % unmodified polymer and 5 to 50 % of impact modifier(s), maintaining th
47、e requirement that the overall composition of thesematerials is polymers made from monomers, at least 70 % of which are methyl methacrylate.JHeat-resistance modified materials are polymerized from 70 to 95 % methyl methacrylate monomer and 5 to 30 % comonomers.D788063First Digit0 = to be specified b
48、y the user.1 = 1000 h at 70 6 2C.2 = 1000 h at 80 6 2C.3 = 1000 h at 90 6 2C.Second Digit0 = to be specified by the user.1 = change in tensile strength and impact strength not to exceedlimits as given in Table 4A after aging in an air-circulating ovenat the conditions indicated by the first digit an
49、d subsequentconditioning according to Section 12.2 = change in tensile strength, tensile elongation, and impactstrength not to exceed limits as given in Table 4B after agingin an air-circulating oven at the conditions indicated by the firstdigit and subsequent conditioning according to Section 12.5.1.3 Suffix T = Light Transmission and Haze, Modifica-tion, as designated by the following digits:First Digit0 = unspecified1 = light diffusing polymer modified, minimum transmission 80 %2 = light diffusing polymer modified, minimum transmission 70 %T1 and T2 materi
