1. Density and relative density

Density and relative density——Density refers to the mass contained in the unit volume of a substance. In short, it is the ratio of mass to volume. Its unit is million grams/meter3 (Mg/m3) or kilogram/meter3 (kg/ m3) or grams/cm3 (g/cm3). Relative density, also known as density ratio, refers to the ratio of the density of a substance to the density of a reference substance under respective specified conditions, or the mass of a certain volume of substance at temperature t1 and the same volume of a reference substance at t2. The ratio of masses at temperature. The commonly used reference material is distilled water, expressed as Dt1/t2 or t1/t2, which is a dimensionless quantity.

2. Melting point and freezing point

Melting point and Freezing point - The temperature at which a substance reaches equilibrium between the liquid and solid states under its vapor pressure is called the melting point or freezing point. This is a phenomenon in which the regular arrangement of atoms or ions in a solid becomes chaotic and activated as the temperature rises, resulting in thermal motion, forming an irregularly arranged liquid. The opposite process is solidification. The temperature at which a liquid becomes a solid is often called the freezing point or freezing point. The difference from the melting point is that heat is released rather than absorbed. In fact, the melting point and freezing point of a substance are the same.

3 Melting range

Refers to the temperature range from the beginning of melting of the substance to complete melting measured by the capillary method.

4. Crystal point

Refers to the phase transition temperature at which a liquid changes from liquid to solid during the cooling process.

5. Pour point

One of the indicators indicating the properties of liquid petroleum products. It refers to the temperature at which the sample begins to stop flowing when cooled under standard conditions, that is, the lowest temperature at which the sample can still be poured when cooled.

6. Boiling point

The temperature at which a liquid boils when heated and turns into a gas. Or the temperature at which a liquid and its vapor are in equilibrium. Generally speaking, the lower the boiling point, the greater the volatility.

7. Boiling range

Under standard conditions (1013.25hPa, 0℃), the distillation volume within the temperature range specified in the product standard.

8. Sublimation

The phenomenon in which solid (crystalline) substances transform directly into gaseous state without passing through liquid state. Such as ice, iodine, sulfur, naphthalene, camphor, mercury chloride, etc. can sublimate at different temperatures.

9. Vaporizing velocity

Evaporation refers to the vaporization phenomenon that occurs on the surface of a liquid. The evaporation rate, also known as the volatilization rate, is generally judged by the boiling point of the solvent. The fundamental factor that determines the evaporation rate is the vapor pressure of the solvent at that temperature, followed by the molecular weight of the solvent.

10. Vapor pressure

Vapor pressure is the abbreviation for saturated vapor pressure. At a certain temperature, a liquid reaches equilibrium with its vapor. The equilibrium pressure at this time changes only due to the properties and temperature of the liquid, which is called the saturated vapor pressure of the liquid at that temperature.

11. Azeotrope

A constant boiling point mixture formed by two (or several) liquids is called an azeotrope, which refers to a mixed solution in equilibrium with the gas phase and liquid phase having exactly the same composition. The corresponding temperature is called the azeotropic temperature or azeotropic point.

12. Refractive index

Refractive index is a physical quantity that expresses the ratio of the speed of light in two different (isotropic) media. The speed of light varies with different media. When light enters another transparent medium with a different density from one transparent medium, due to the change in speed, the direction in which it proceeds changes, so it is called refraction. The ratio of the sine of the incident angle of light to the sine of the angle of refraction, or the ratio of the speed of light when passing through a vacuum to when passing through a medium, is the refractive index. The generally expressed refractive index n refers to the value of light entering any medium from air. The refractive index usually referred to is measured at tC using sodium yellow light (D line), so it is expressed as ntD. If measured at 20°C, it is n20D.

13. Flashing point

Flash point, also known as ignition flash point, is one of the indicators indicating the properties of flammable liquids. Refers to the lowest temperature at which a flammable liquid is heated to the point where a flash fire occurs when the mixture of vapor pressure and air on the liquid surface comes into contact with a flame. Flashovers are usually light blue sparks that extinguish in a flash and cannot continue to burn. Flashover is often a precursor to a fire. There are open cup method and closed cup method for measuring flash point. Generally, the former is used to measure high flash point liquids, and the latter is used to measure low flash point liquids.

14. Ignition point

The ignition point, also known as the ignition point, is one of the indicators indicating the properties of flammable liquids. It refers to the lowest temperature at which a flammable liquid can continue to burn when heated to the point where the mixture of vapor and air on its surface ignites immediately upon contact with a flame. The ignition point of flammable liquids is 1 to 5°C higher than the flash point. The lower the flash point, the smaller the difference between fire point and flash point.

15. Spontaneous ignition point

The lowest temperature at which a flammable substance can catch fire without contact with an open flame is called the autoignition point. The lower the auto-ignition point, the greater the risk of fire. The autoignition point of the same substance varies with pressure, concentration, heat dissipation and other conditions and testing methods.

16. Explosive limits

When flammable gas, vapor of flammable liquid or dust of combustible solid is mixed with air or oxygen under a certain temperature and pressure to reach a certain concentration range, it will explode when encountering a fire source. This certain concentration range is called the explosion limit or combustion limit. If the composition of the mixture is not within this certain range, no matter how much energy is supplied, it will not catch fire. When steam or dust is mixed with air and reaches a certain concentration range, the lowest concentration that will burn or explode when encountering a fire source is called the lower explosion limit; the highest concentration is called the upper explosion limit. Explosion limits are usually expressed as the volume percentage of vapor in the mixture, that is, % (vol); dust is expressed as mg/m3 concentration. If the concentration is lower than the lower explosion limit, even an open flame will not explode or burn, because air accounts for a large proportion at this time, and the concentration of flammable vapor and dust is not high; if the concentration is higher than the upper explosion limit, although there will be a large amount of flammable substances, there will be a lack of The combustion-supporting oxygen will not explode even if it encounters an open flame without air supplementation. Flammable solvents have a certain explosion range. The wider the explosion range, the greater the danger.

17. Viscosity

Viscosity is the internal frictional resistance produced by a fluid (liquid or gas) during flow. Its size is determined by factors such as substance type, temperature, concentration, etc. It is generally the abbreviation of dynamic viscosity, and its unit is Pa·second (Pa·s) or milliPa·second (mPa·s). Viscosity is divided into dynamic viscosity, kinematic viscosity, and relative viscosity. The three are different and cannot be confused. The viscosity can also be measured by Tu-4 or Tu-1 cup, and its unit is seconds (s).

18. Mooney viscosity

Mooney viscosity, also known as rotational (Mooney) viscosity, is a value measured with a Mooney viscometer, which basically reflects the degree of polymerization and molecular weight of synthetic rubber. According to the GB 1232 standard, the rotational (Mooney) viscosity is represented by the symbol Z100℃ 1 4. Among them, Z——rotational viscosity value; 1——preheating time is 1min; 4——rotation time is 4min; 100℃——test temperature is 100℃. It is customary to express Mooney viscosity by ML100℃ 1 4.

19. Solubility

The maximum amount of a substance that can be dissolved in a given amount of solvent at a certain temperature and pressure is called solubility. The solubility of a solid or liquid substance is generally expressed by the number of grams of the substance that can be dissolved in 100g of solvent. The solubility of a gas solute is often expressed in milliliters of dissolved gas per liter of solvent.

20. Solubility parameter

The solubility parameter, also known as the solubility parameter, is a measure of intermolecular forces. The energy that brings molecules together is called cohesive energy. The cohesive energy per unit volume is called cohesive energy density (CED), and the square root of CED (CED) 1/2 is defined as the solubility parameter, code-named δ or SP.

21. Surface tension and surface energy

Surface tension and surface energy - The attraction of molecules inside a liquid puts the molecules on the surface under an inward force. This force causes the liquid to minimize its surface area and form a force parallel to the surface, which is called surface tension. In other words, it is the mutual traction force within unit length between two adjacent parts of the liquid surface. It is a manifestation of molecular force. The unit of surface tension is N/m. The size of surface tension is related to the nature, purity and temperature of the liquid. The surface tension multiplied by the area of the surface is the surface energy. The greater the surface tension, the greater the surface area and the greater the surface energy it has.

22. Specific heat capacity

The amount of heat needed to be absorbed when the temperature of each kilogram of material increases by 1K is called specific heat capacity, and the unit is kJ/(kg·K). When the pressure remains constant, the heat absorbed when the temperature rises by 1K is called the constant pressure specific heat capacity.

• Thermal conductivity

Thermal conductivity used to be called thermal conductivity or thermal conductivity coefficient, which reflects the heat conduction ability of a substance. That is, take two parallel planes 25px apart and with an area of 25px2 inside the object perpendicular to the direction of heat conduction. If the temperature difference between these two planes is 1K, then the heat conducted from one plane to the other plane in ls is defined as the substance Thermal conductivity, its unit is W/(m·K).

24. Water content

Moisture contained in a substance, excluding water of crystallization and water of association. It is usually expressed as the mass percentage of the original mass of the sample and the mass of the sample after water loss.

25. Water absorption

It is a measure of how well a substance absorbs water. It refers to the mass percentage increased by soaking a substance in water for a certain time at a certain temperature.

26. Ash

Ash, also known as burning residue, refers to the residue of oxides and salts formed from its mineral components after evaporation and burning, expressed as a percentage.

27. Needle penetration

Penetration is expressed by the depth of a standard needle penetrating vertically into an asphalt sample under certain conditions of load, time and temperature. The unit is 1/10mm. Unless otherwise specified, the total weight of the standard needle, needle connecting rod and additional weight is 100±0.1g, the temperature is 25℃, and the time is 5s. The greater the penetration, the softer, that is, the smaller the consistency; the opposite, the harder, that is, the greater the consistency.

28. Hardness

Hardness is the material's resistance to external forces such as impressions and scratches. According to different test methods, there are Shore hardness, Brinell hardness, Rockwell hardness, Mohs hardness, Barcol hardness, Vichers hardness, etc. The value of hardness is related to the type of hardness tester. Among commonly used hardness testers, the Shore hardness tester has a simple structure and is suitable for production inspection. Shore hardness testers can be divided into type A, type C and type D. Type A is used to measure soft rubber, and types C and D are used to measure semi-hard and hard rubber.

29. Aniline point (A.P.)

The aniline point is the lowest temperature at which equal volumes of petroleum alkanes and aniline dissolve with each other, and is used to express the content of paraffinic saturated hydrocarbons. The level of aniline point is related to the chemical composition. The higher the aniline point, the more alkane content; the lower the aniline point, the more aromatic hydrocarbon content.

30. Volume resistivity

Also called volume resistance and volume resistivity, it is an important indicator that characterizes the electrical properties of dielectric or insulating materials. Indicates the resistance of the 25px3 dielectric to leakage current, in Ω·m or Ω·cm. The larger the volume resistivity, the better the insulation performance.

31. Oil absorption

The amount of oil required when the absolute surface of a certain mass of pigment (filler) particles is completely soaked with oil.

32. Acid value

Acid value, also known as acid value, represents an indicator of organic substances and is the number of milligrams of potassium hydroxide (KOH) required to neutralize the free acid in the non-volatile matter of 1 g of organic substances, that is, mgKOH/g.

33. Hydroxyl value

The number of milligrams of potassium hydroxide (KOH) equivalent to the hydroxyl groups in 1g of the sample is expressed in mgKOH/g.

34. Iodine value

An indicator of the degree of unsaturation of organic matter. It is the mass percentage of iodine that can be absorbed by 1g of sample. The higher the degree of unsaturation, the greater the iodine value.

35. Epoxy value

The epoxy value represents the equivalent number of epoxy groups contained in 100g of epoxy resin, that is, epoxy value = epoxy equivalent / 100 = number of epoxy groups / molecular weight of epoxy resin * 100%. The larger the epoxy value, the smaller the molecular weight and the lower the viscosity.

36. Epoxy equivalent

Epoxy equivalent weight represents the molecular weight of the resin corresponding to each epoxy group. Epoxy equivalent = molecular weight of epoxy resin/number of epoxy groups

37.HLB value

It is the abbreviation of Hydrophile-Lipophile-Balance, which is used to measure the relative strength of the polar group and non-polar group in the surfactant molecule. If the polar group is stronger, its HLB value will be larger and the hydrophilicity will be stronger; if the non-polar group is longer, its HLB value will be smaller and its hydrophilicity will be worse.

38. Critical micell concentration

Critical micelle concentration, also called critical micelle concentration, or CMC for short. The concentration range in which the properties of an emulsifier solution suddenly change is called the critical micelle concentration of the emulsifier. After the emulsion system reaches the critical micelle concentration, many emulsifier molecules aggregate to form micelles. The unit of CMC is mol/L.

39. Degree Baume

The value given by the Baume meter using a special graduation method in the glass tube float meter is called Baume degree, and its symbol is °B′e. Used to indirectly give the density of a liquid.

40. Solid content

Solid content, also known as non-volatile matter content and total solid content (TS), represents the ratio of the mass of the residue after the sample is heated at a certain temperature to the mass of the sample, expressed as a percentage.

41. Surface-active agent

Also known as surfactant, it is a substance that can significantly change the surface tension of liquid or the interfacial tension of two phases. In other words, it can be strongly adsorbed on the surface of other substances or aggregated on the surface of the solution, reducing the liquid or Surface tension of solids.

42. Relative humidity

One way to express humidity is the ratio of absolute humidity to saturated absolute humidity under the same conditions (same temperature and pressure), that is, under the same conditions, the actual mass and saturated water vapor contained in the air (or other gases) Water vapor mass ratio. Usually expressed as a percentage.

43. Apparent density

It was once called bulk density, bulk density, pseudo density, and apparent density, and represents the mass of material per unit volume (including voids).

44. Isomer

The phenomenon in which compounds have the same molecular formula but different structures and properties is called isomerism. Compounds that can undergo isomerism are called isomers, or isomers for short.

45. Relative molecular mass

Molecular weight, for short, refers to the ratio of the average mass of molecules or specific units of a substance to (1/12) the atomic mass of the nuclide 10 6 C. The symbol is Mr.

46. Number average molecular weight

Polymers are composed of homogeneous mixtures with the same chemical composition but different degrees of polymerization, that is, a mixture of polymers with different molecular chain lengths. The average molecular weight is usually used to characterize the size of a molecule. The statistical average based on the number of molecules is called the number average molecular weight, and the symbol is (ˉMn).

47. Degree of polymerization

The number of links that make up a polymer molecular chain is called the degree of polymerization, code-named n or DP, and can be used as a measure of the molecular weight of the polymer.

48. Molecular weight distribution

Due to the different sizes of polymers, in addition to the statistical properties of molecular weight, they also have polydispersity, that is, molecular weight distribution. The same average molecular weight will have different molecular weight distributions and show different properties.

49. Homopolymer

Polymers made from the same monomer and composed of repeating chain segments are called homopolymers.

50. Copolymer

Polymers formed by the polymerization of two or more monomers or monomers and polymers are called copolymers, which are divided into block copolymers, random copolymers, regular copolymers, and graft copolymers. wait.

51. Graft copolymer

A copolymer in which some atoms of the polymer main chain are connected with side chains of polymer segments that have a different chemical structure from the main chain. It is called a graft copolymer, such as grafted chloroprene rubber and SBS graft copolymer. .

52. Prepolymer

A polymer with a lower molecular weight (below 1500) with a degree of polymerization between the monomer and the final polymer. It is also called an oligomer or an oligomer. It is a polymer composed of a small number of chain links. Such as dimers, trimers, tetramers, or mixtures of these oligomers.

53. Glass transition temperature

The approximate midpoint of a narrow temperature range in which amorphous or semi-crystalline polymers transition from a viscous fluid state or a highly elastic state to a glassy state (or vice versa) is called the glass transition temperature, usually expressed as Tg, and is the heat resistance an indicator of.

54. Brittle temperature

A measure of the thermal properties of a polymer. When the sample is impacted by a punch with a certain energy, the temperature at which the cracking probability of the sample reaches 50% is called the embrittlement temperature, also called the brittle breaking point.

55. Heat deflection temperature under load

A measure of the heat resistance of a polymer is to immerse the polymer sample in a suitable heat transfer medium that heats up at a constant rate. Under the action of a simply supported beam static bending load, the bending deformation of the sample reaches the specified level. The temperature at which the value is reached is the heat distortion temperature, or HDT for short.

56. Minimum filming temperature

The lowest temperature at which a synthetic emulsion system forms a continuous film is called the minimum film forming temperature, or MFT for short.

57. Softening point

On the polymer sample, a certain load is applied in a certain form and heated at a specified heating rate until the deformation of the sample reaches a specified value, which is the softening point.

58. Marten’s test

A method for evaluating the tendency of materials to deform at high temperatures. In the heating furnace, the sample is subjected to a certain bending stress and heated at a certain rate. The temperature at which the heated free end of the sample produces a specified deflection is called the Martin temperature.

59. Vicat softening point test

A method for evaluating the high-temperature deformation tendency of thermoplastics. Under constant-speed heating conditions, a flat-topped needle with a specified load and a cross-sectional area of 1mm2 is placed on the sample. The temperature when the flat-topped needle penetrates 1mm into the sample is the measured Vicat softening. temperature.

60. Melt index

Melt index, abbreviated as MI, is an index that reflects the flow characteristics and molecular weight of thermoplastic resin melt. Under a certain temperature and load, the mass value of the melt passing through a standard capillary tube within 10 minutes is expressed in g/10min.

61. Stress relaxation

The phenomenon that the deformation is fixed and the stress attenuates with the extension of the action time is called stress relaxation.

62. Creep

When the stress remains constant, the phenomenon of deformation changing with time is called creep.

63. Shrinkage ration

Define the percentage of the shrinkage amount to the size before shrinkage, and the shrinkage amount is the difference between the size before and after shrinkage.

64. Internal stress

In the absence of external force, the stress generated inside the adhesive layer (material) due to defects, temperature changes, solvent effects, etc.

65. Tensile strength

Tensile strength is the maximum tensile stress when the sample is stretched to fracture. This commonly used terminology used to be very inconsistent. It was called tearing force, tearing strength, tensile strength, tensile strength, and strength. According to the GB 6039-85 standard, it is uniformly called tensile strength, and the unit is MPa.

66. Shear strength

Shear strength, once called shear strength, refers to the maximum load that a unit bonding area can withstand parallel to the bonding area. The commonly used unit is MPa.

67. Peel strength

It was once called peel strength, which refers to the maximum damage load that can be withstood per unit width. It is a measure of the wire's stress capacity, and the unit is kN/m.

68. Specific strength

The ratio of a material's tensile strength to its density is called specific strength.

69. Elongation

The increase in length of the specimen under tension, expressed as a percentage of the original length.

70. Swelling

The phenomenon that the polymer absorbs solvent molecules and expands in volume is called swelling. Swelling is divided into finite swelling and infinite swelling. Infinite swelling is dissolution.

71. Emulsion

The phenomenon of dispersing one insoluble liquid in another liquid in the presence of an emulsifier is called emulsification.

72. Gelatinization

A phenomenon in which starch substances and water turn into a viscous translucent gel or paste at a certain temperature.

73. Compatibility

When two or more substances are mixed, they do not have the ability to reject and separate.

74. Mastication

Masting, also known as mastication and rolling, refers to the transformation of raw rubber from a strong elastic state to a soft and plastic state under the action of mechanical force, heat and oxygen, that is, to increase its plasticity (fluidity) The process is called mastication, and the essence of mastication is to reduce molecular weight, viscosity, and viscosity flow temperature. The plasticized raw rubber is called plasticized rubber.

75 Milling

Mixing is a process in which plasticized rubber or raw rubber with certain plasticity and various compounding agents are uniformly mixed through mechanical action. The quality of the rubber compound obtained after mixing has a great influence on the performance of the prepared adhesive.

76 Valcanization

Vulcanization is a process in which rubber, sulfur and accelerators are combined under a certain temperature and pressure to cause a cross-linking reaction between the rubber macromolecular chains, which is the process in which plastic rubber is converted into elastic rubber or hard rubber. Broadly speaking, vulcanization refers to a process in which the rubber material is treated with chemical or physical methods to transform the rubber macromolecules from linear to network structure through cross-linking, thereby improving the physical, mechanical and chemical properties of the rubber.

77 Crosslinking

Refers to the chemical bonding between the main chains of linear polymer molecules.

78 Scorching

Scorch refers to the early vulcanization phenomenon of rubber compounds during processing. In order to avoid the risk of scorching, an anti-scorch agent can be added, such as sodium acetate added during mixing of neoprene rubber.

79 Oil resistance

The ability of a material to resist swelling, dissolution, cracking, deformation, or reduction in physical properties caused by oil.

80 Solvent resistance

The ability to resist swelling, dissolution, cracking or deformation caused by solvents.

81 Chemical resistance

Resistance to acids, alkalis, salts, solvents and other chemicals.

82 Water resistance

The ability of a material to maintain its physical and chemical properties after being exposed to water or moisture.

83 Flame resistance

The ability of a material to resist burning when in contact with a flame or to hinder continued combustion when removed from the flame

84 Weatherability

The resistance of a material to exposure to sunlight, heat and cold, wind and rain, and other climatic conditions.

85 Durability

Durability is also known as stability and service life. That is, the ability to maintain its performance for a long time under the combined action of external environmental factors.

86 Aging

During processing, storage and use, due to the action of external factors (heat, light, oxygen, water, radiation, mechanical force and chemical media, etc.), a series of physical or chemical changes occur, making the polymer material cross-linked and brittle. , cracking and sticky, discoloration and cracking, rough blistering, surface powdering, delamination and peeling, gradually deteriorating performance, and even losing mechanical properties and making it unusable. This phenomenon of change is called aging.

87 Lethal dose

The median lethal dose is an important data to measure the toxicity of poisons. When a poison is given orally or injected to some animals (such as rats, rabbits, etc.), the dose that can kill half of the animals is called the median lethal dose, abbreviated as LD50, expressed in mg/kg. The smaller the LD50, the greater the toxicity. Those with LD50 exceeding 5000 mg/kg can be considered non-toxic.

88 Maximum allowable concentration

In order to prevent acute or chronic poisoning of humans caused by chemical substances, governments around the world have stipulated that the toxic vapor or dust contained in the air in the workplace should not exceed a value, called the maximum allowable concentration, or MAC for short, usually expressed in mg/m3 or ppm. express.

89 Storage life; shelf life

The longest period of time that materials with changing properties can maintain their usable performance when stored under certain conditions.

90 penetration ratio

Determine the percentage obtained by multiplying the ratio of the penetration of the sample after evaporation loss to the original penetration by 100.