Tech Talk Blog

Diallyl Phthalate (DAP)
The term DAP is used both for the monomeric and polymeric forms. The monomer [C₆H₄(COOCH₂CHCH₂)₂] is used as a cross-linking agent in unsaturated polyester resins. As a polymer, it is used in the production of thermosetting molding powders, casting resins and laminates. This material can be bonded using most epoxies. Paint adhesion can be improved using plasma pretreatment.

Epoxy
Thermosetting resins that, in the uncured form, contain one or more reactive epoxide or oxirane groups. These epoxide groups serve as cross-linking points in the subsequent curing step, in which the uncured epoxy is reacted with a curing agent or hardener. Cross-linking is accomplished through the epoxide groups as well as through hydroxyl groups that may be present. Most conventional unmodified epoxy resins are produced from epichlorohydrin (chloropropylene oxide) [CH₂OCHCH₂Cl] and bisphenol A [(CH₃)₂C(C₆H₄OH)₂]. The other types of epoxy resins are phenoxy resins, novolac resins, and cycloaliphatic resins. Epoxy resins are used as protective coatings, bonding adhesives, in building and construction, and for electrical , and many other uses….This material can be modfied for improved strength and or temperature resistance.

Fluoropolymer
A family of thermoplastic resins analogous to polyethylene in which some of the hydrogen atoms attached to the carbon chain are replaced by fluorine or fluorinated alkyl groups. In some cases, other halogens such as chlorine are also part of the molecule. The most common commercial fluoropolymers are: FEP (fluorinated ethylene-propylene) from tetrafluoroethylene [C₂F₄] and hexa-fluoropropylene [C₃F₆]; PTFE (polytetra fluoroethylene) from the polymerization of tetrafluoroethylene and ethylene [C₂H₄]; PFA (perfluoroalkoxy) from tetrafluoroethylene and perfluoropropyl vinyl ether [C₃H₇C₄OF₅]; PCTFE (polychlorotrifluoro-ethylene) from chlorotrifluoro-ethylene monomer [C₂F₃CI]; CTFE-VDF (polychlorotrifluoroethylenevinylidene fluoride) from chlorotrifluoroethylene and vinylidene fluoride [C₂H₂F₂]; E-CTFE (polyethylenechlorotrifluoroethylene) from chlorotrifluoroethylene and ethylene; PVDF (polyvinylidene fluoride) from vinylidene fluoride monomer; and PVF (polyvinyl fluoride) from vinyl fluoride monomer [C₂H₃F]. Typical applications for fluoropolymers are found in electrical/ electronic uses and pipe and chemical processing equipment. Requires chemical etch or plasma treatment for adhesion.

Melamine-Formaldehyde
Thermosetting resins formed by the condensation reaction of formaldehyde [HCHO] and melamine [C₃N₃(NH₂)₃]. The chemistry is analogous to that of ureaformaldehyde except that the three amino groups of melamine provide more possibilities for cross-linking, are more highly reactive, and all six hydrogen atoms of melamine will react, forming the hexamethyl compound. Typical applications are found in bonding and adhesives, coatings, and consumer products.

Nitrile Resins
Thermoplastic resins composed of acrylonitrile [CH₂CHCN] along with comonomer such as acrylates, methacrylates, butadiene [CH₂CHCHCH₂] and styrene [C₆H₅CHCH₂]. Both straight copolymers and copolymers grafted onto elastomeric backbones are available. The unique property of these materials is outstanding resistance to passage of gases and water vapor, making them useful in packaging applications.

Nylon
A generic name for a family of long-chain polyamide engineering thermoplastics which have recurring amide groups [-CO-NH-] as an integral part of the main polymer chain. Nylons are synthesized from intermediates such as dicarboxylic acids, diamines, amino acids and lactams, and are identified by numbers denoting the number of carbon atoms in the polymer chain derived from specific constituents, those from the diamine being given first. The second number, if used, denotes the number of carbon atoms derived from a diacid. Commercial nylons are as follows: nylon 4 (polypyrrolidone)-a polymer of 2-pyrrolidone [CH₂CH₂CH₂C(O)NH]; nylon 6 (polycaprolactam)-made by the polycondensation of caprolactam [CH₂(CH₂)₄NHCO]; nylon 6/6-made by condensing hexamethylenediamine [H₂N(CH₂)₆NH₂] with adipic acid [COOH(CH₂)₄COOH]; nylon 6/10-made by condensing hexamethylenediamine with sebacic acid[COOH(CH₂)₈COOH]; nylon 6/12-made from hexamethylenediamine and a 12-carbon dibasic acid; nylon 11-produced by polycondensation of the monomer 11-amino-undecanoic acid [NH₂CH₂(CH₂)₉COOH]; nylon 12-made by the polymerization of laurolactam [CH₂(CH₂]₁₀CO)or cyclododecalactam, with 11 methylene units between the linking -NH-CO- groups in the polymer chain. Typical applications for nylons are found in automotive parts, electrical/electronic uses, and packaging. This material can be easily bonded after plasma treatment or with methylene chloride/ethylene dichloride.

Petroleum Resins
Thermoplastic resins obtained from a variable mixture unsaturated monomers recovered as byproduct from cracked and distilled petroleum streams. They also contain indene [C₆H₄CH₂CHCH], which is copolymerized with a variety of other monomers including styrene [C₆H₅CHCH₂], vinyl toluene [CH₂CHC₆H₄CH₃], and methyl indene [C₆H₃CH₃CH₂CHCH]. Typical applications are found in adhesives, printing inks, rubber compounding, and surface coatings.

Phenolic
These thermosetting resins are credited with being the first commercialized wholly synthetic polymer or plastic. The basic raw materials are formaldehyde [HCHO] and phenol [C₆H₅OH], although almost any reactive phenol or aldehyde can be used. The phenols used commercially are phenol, cresols [CH₃C₆H₄OH], xylenols [(CH₃)₂C₆H₃OH], p-t-butylphenol [C₄H₉C₆H₄OH], p-phenylphenol [C₆H₅C₆H₄OH], bisphenols [(C₆H₄OH)₂], and resorcinol [C₆H₄(OH)₂]. The aldehydes used are formaldehyde and furfural [C₄H₃OCHO]. In the uncured and semi- cured condition, phenolic resins are used as adhesives, casting resins, potting compounds, and laminating resins. As molding powders, phenolic resins can found in electrical uses. Easily bonded using epoxies. Enhanced paint and coating adhesion can be accomplished using plasma treatments.

Polyamide-Imide
Engineering thermoplastic resins produced by the condensation reaction of trimellitic anhydride [OCC₆H₂C₂O₃] and various aromatic diamines. Typical applications are found in aerospace, automotive and heavy equipment industries. Plasma treatment is very effective at improving coating and adhesive adhesion.

Polyarylates
Engineering thermoplastic resins produced by interfacial polymerization of an aqueous solution of the disodium salt of bisphenol A [(CH₃)₂C(C₆H₄OH)₂] with phthalic acid chlorides [C₆H₄(CO)₂Cl₂] in methylene chloride (CH₂Cl₂]. The major use of polyarylates is in outdoor lighting.

Polybutylene
Thermoplastic resins produced via stereospecific Ziegler-Natta polymerization of butene-1 monomer [CH₂CHCH₂CH₃]. Typical applications are found in pipe and packaging film.

Polycarbonate
Engineering thermoplastic resins produced by (1) phosgenation of dihydric phenols, usually bisphenol A [(CH₃)₂C(C₆H₄OH)₂], (2) ester exchange between diaryl carbonates and dihydric phenols, usually between diphenyl carbonate [(C₆H₅O)₂CO] and bisphenol A and (3) interfacial polycondensation of bisphenol A and phosgene [COCl₂]. Typical applications are found in glazing, appliances, and electrical uses. Can be bonded using solvents like ethylene dichloride. But, a more “green” approach is by using plasma treatments.

If you have any questions about the list, Ask The Experts. And if you’re a visual learner, look to our Video Learning Center for more information.

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Tags: adhesion, chemical structure, Plastic Resin, resin, treatment

This entry was posted on Wednesday, November 18th, 2009 at 5:00 AM and is filed under Surface Modification. You can follow any responses to this entry through the RSS 2.0 feed. Responses are currently closed, but you can trackback from your own site.