Classification of Polyimide

Since polycondensation polyimide has the disadvantages as mentioned above, in order to overcome these disadvantages, polymerisation polyimide has been developed. The main ones that have gained wide application are polybismaleimide and norbornene-based end-capped polyimides. Usually, these resins are low relative molecular mass polyimides with unsaturated groups at the ends, and then polymerised by unsaturated end groups when applied.
?Polybismaleimide
Polybismaleimide is made by polycondensation of maleic anhydride and aromatic diamine. Compared with polyimide, its performance is not bad, but the synthesis process is simple, easy post-processing, low cost, can be easily made into a variety of composite products. But the cured material is more brittle.
?Norbornene-based capped polyimide resin
One of the most important is developed by NASA Lewis Research Center, a class of PMR (for insitu polymerization of monomer reactants, monomer reactants in situ polymerization) type polyimide resins. RMR-type polyimide resins are aromatic tetracarboxylic acid dialkyl ester, aromatic diamine and 5-norbornene-2, 3-dicarboxylic acid monoalkyl ester, aromatic diamine and 5-norbornene-2, 3-dicarboxylic acid monoalkyl esters. 3-dicarboxylic acid monomers such as dialkyl esters of aromatic tetracarboxylic acids, aromatic diamines and monoalkyl esters of 5-norbornene-2,3-dicarboxylic acid are dissolved in a tasted alcohol (e.g., methanol or ethanol) to produce a solution that can be used directly to impregnate fibres. Polyimide is a molecular structure containing imide-based chain links of aromatic heterocyclic polymer compounds, the English name Polyimide (referred to as PI), can be divided into benzene-type PI, soluble PI, polyamide-imide (PAI) and polyetherimide (PEI) four categories.

Extended Reading?

PC-37 – Amine Catalysts (newtopchem.com)

Dabco foaming catalyst/polyurethane foaming catalyst NE300 – Amine Catalysts (newtopchem.com)

DABCO EG/PC CAT TD 33EG/Niax A-533 – Amine Catalysts (newtopchem.com)

FASCAT4100 catalyst – Amine Catalysts (newtopchem.com)

T120 1185-81-5 di(dodecylthio) dibutyltin – Amine Catalysts (newtopchem.com)

DABCO 1027/foaming retarder – Amine Catalysts (newtopchem.com)

DBU – Amine Catalysts (newtopchem.com)

bismuth neodecanoate/CAS 251-964-6 – Amine Catalysts (newtopchem.com)

stannous neodecanoate catalysts – Amine Catalysts (newtopchem.com)

polyurethane tertiary amine catalyst/Dabco 2039 catalyst – Amine Catalysts (newtopchem.com)

Does using polyimide resin powder affect the air?

Polyimide resin powder in the sintering curing process, may produce some emissions, mainly including: 1. formaldehyde: due to the polyimide resin powder contains formaldehyde groups, so in the sintering curing, will release a small amount of formaldehyde exhaust. 2. ammonia: polyimide resin powder in the sintering curing process, may release a small amount of ammonia exhaust. 3. carbon dioxide: in the high temperature, polyimide resin powder will decomposition Carbon dioxide exhaust gas is generated. Precautions: 1. Temperature and time should be strictly controlled during the sintering and curing process to avoid generating excessive exhaust gases. 2. Necessary exhaust and protective measures should be taken to ensure the safety of the working environment. 3. Hazards: 1. Formaldehyde is a hazardous substance and is harmful to human health. Long-term exposure to formaldehyde may lead to respiratory diseases, cancer and other illnesses. 2. Ammonia and carbon dioxide are also harmful gases. Long-term exposure to these gases may cause headaches, coughing, shortness of breath and other uncomfortable symptoms. At the same time, the emission of these gases may also pollute the atmosphere and affect air quality.
During the sintering and curing process of polyimide resin powder, the main exhaust gases produced are carbon monoxide, carbon dioxide, nitrogen oxides, sulphur oxides, nitrates, organic gases and water vapour. Among them, carbon monoxide and carbon dioxide are mainly emitted by fuel combustion; nitrogen oxides and sulphur oxides are mainly generated due to the organic substances contained in the surface materials during sintering; nitrates are mainly generated due to the nitrides contained in the structural materials; organic gases are mainly generated due to the organic substances contained in the surface materials during sintering; and water vapour is mainly generated due to the water contained in the structural materials.

Extended Reading?

PC-37 – Amine Catalysts (newtopchem.com)

Dabco foaming catalyst/polyurethane foaming catalyst NE300 – Amine Catalysts (newtopchem.com)

DABCO EG/PC CAT TD 33EG/Niax A-533 – Amine Catalysts (newtopchem.com)

FASCAT4100 catalyst – Amine Catalysts (newtopchem.com)

T120 1185-81-5 di(dodecylthio) dibutyltin – Amine Catalysts (newtopchem.com)

DABCO 1027/foaming retarder – Amine Catalysts (newtopchem.com)

DBU – Amine Catalysts (newtopchem.com)

bismuth neodecanoate/CAS 251-964-6 – Amine Catalysts (newtopchem.com)

stannous neodecanoate catalysts – Amine Catalysts (newtopchem.com)

polyurethane tertiary amine catalyst/Dabco 2039 catalyst – Amine Catalysts (newtopchem.com)

Polyimide for special engineering plastics

Polyimide is the molecular structure contains an aromatic heterocyclic polymer compounds of polyimide-based chain links, the English name Polyimide (PI for short), can be divided into benzene-type PI, soluble PI, polyamide-imide (PAI) and polyetherimide (PEI) four categories.
PI is currently one of the best varieties of engineering plastics heat resistance, some varieties can withstand long-term 290 ? high temperature for a short period of time to withstand a high temperature of 490 ?, but also very low temperature, such as in the -269 ? liquid helium will not be brittle. In addition, mechanical properties, fatigue resistance, flame retardant, dimensional stability, electrical properties are good, molding shrinkage is small, resistant to oil, general acids and organic solvents, not alkali resistance, excellent friction resistance, abrasion properties. And PI is non-toxic, can be used to manufacture tableware and medical equipment, and withstand thousands of times disinfection.
PI moulding methods include compression moulding, impregnation, injection moulding, extrusion, die-casting, coating, casting, laminating, foaming and transfer moulding. PI has applications in aerospace, automotive, electronic and electrical appliances, industrial machinery, etc. It can be used as engine combustion system parts, jet engine components, compressor and generator parts, fasteners, spline joints and electronic contacts, as well as automotive engine parts, bearings, piston bushings, timing gears, printed wiring boards, insulating materials, heat-resistant cables, terminal blocks, sockets in the electronics industry, high temperature resistant self-lubricating bearings, and sockets in the machinery industry. High-temperature self-lubricating bearings, compressor blades and piston machine, sealing rings, equipment heat shield, thrust washers, bushings, etc..
Polyetherimide has excellent mechanical properties, electrical insulation properties, irradiation resistance, high and low temperature resistance and abrasion resistance, self-extinguishing, good melt flow, the shrinkage rate of the moulding is only 0.5 % ~ 0.7 %. PEI can be injection and extrusion moulding, post-processing is easier, can be adhesive or a variety of welding method and other materials, PEI in the electronics and electrical appliances, aerospace, automotive, medical equipment and other industries have been widely used. GE is the world’s largest producer of PEI, there are some engineering plastics modification company to provide PEI alloys and other modified products. The trend of development is the introduction of p-phenylenediamine structure or with other special engineering plastics alloy to improve its heat resistance; or with PC, PA and other engineering plastics alloy to improve its mechanical strength.
Polyamide-imide strength is currently the highest in the non-reinforced plastics, the colour of the material tensile strength of 190MPa, bending strength of 250MPa. 1.8MPa load heat deflection temperature of 274 ?. PAI has good ablation resistance and high temperature, high frequency under the electromagnetic properties of metals and other materials have good adhesive properties. Mainly used for gears, rollers, bearings and copier separation claws, etc., but also for aircraft ablative materials, magnetic permeability and structural materials.PAI by Amoco company was the first to develop a successful and commercialised, in addition to Amoco, Japan’s Toray can also provide moulding plastics. Its development direction is to enhance the modification, and alloy with other plastics.

Extended Reading?

PC-37 – Amine Catalysts (newtopchem.com)

Dabco foaming catalyst/polyurethane foaming catalyst NE300 – Amine Catalysts (newtopchem.com)

DABCO EG/PC CAT TD 33EG/Niax A-533 – Amine Catalysts (newtopchem.com)

FASCAT4100 catalyst – Amine Catalysts (newtopchem.com)

T120 1185-81-5 di(dodecylthio) dibutyltin – Amine Catalysts (newtopchem.com)

DABCO 1027/foaming retarder – Amine Catalysts (newtopchem.com)

DBU – Amine Catalysts (newtopchem.com)

bismuth neodecanoate/CAS 251-964-6 – Amine Catalysts (newtopchem.com)

stannous neodecanoate catalysts – Amine Catalysts (newtopchem.com)

polyurethane tertiary amine catalyst/Dabco 2039 catalyst – Amine Catalysts (newtopchem.com)

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