Polymers reactive liquid

Functionality. For reactive liquid polymers, the most important property is the functionality. Functionality is determined from number average molecular weight (Mn) and hydroxyl number by the following equation ... 

B. F. Goodrich Co., Product Description RLP-1 (Hycar Reactive Liquid Polymers), Cleveland, Ohio. 

The initial solubility of a reactive liquid polymer in epoxy resins before cure is a critical condition not only for chemical reactions but also for the in situ formation of rubbery domains. A good initial solubility... 

A process was developed in 1943 to make polysulfides as a reactive liquid polymer with mercaptan-end groups. These terminals lend themselves readily to oxidation to high molecular weight elastomeric compounds. As a result, the liquid polymers could be compounded with greater facility than the solid elastomers. 

BF Goodrich Chemical Group, "Toughen Epoxy Resins with Hycar Reactive Liquid Polymers" 1980, RLP-2. 

C.K. Riew, "Amine-Terminated Reactive Liquid Polymers Modification of Thermoset Resins, Rub. Chem. Techn., 5 , No. 2 (5/6/1981). 

Ralph Drake has degrees from Case-Western Research University. He has been with B. F. Goodrich Chemical Group for 26 years and spent much of that time associated with new products, many of them adhesive raw materials. He is currently Marketing Manager for Reactive Liquid Polymers. He has over 40 patents and technical publications. 

Reactive liquid polymers (RLPs) The Uquid rubbers most often used in epoxy adhesives are those based on acrylonitrile-butadiene copolymers or on long-chain polyethers. To act as effective tougheners, however, they cannot be directly added to the formulation but have to be prereacted with some of the epoxy resin, or sometimes with the amino hardeners in two component paste adhesives (adduct fonnatiou). To achieve this, only RLPs with reactive eud groups are used by the formulator. 

Addition of p-cresol formaldehyde (PCF) into phenolic/NBR blends resulted in rednction in the domain size of the dispersed phase and improvement in mechanical properties [244]. PCF resin has an intermediate polarity compared with NBR and resole and can react faster with NBR. Therefore, PCF molecules are likely to be concentrated at the phenolic/NBR interface and act as an external compatibilising agents [245]. Thus compatibility and chemical bonding between NBR and phenolic resin is improved, leading to the enhancement in properties. The other materials used as toughening agents of phenolic resin include elastomers such as natural rubber and nitrile rubber [246, 247], reactive liquid polymers [248] and thermoplastics such as polysulfone, polyamide, polyethylene oxide [249, 250]. 

Hycar, Reactive liquid polymers, BFGoodrich Specialty Chemicals... 

HP Multipolymer Acrylic-based multipolymer sheet, Cyro HT-1 Polyimide, DuPont Hyccr Reactive liquid polymers, BFGoodrich... 

Hycar reactive liquid polymers produced by Goodrich Company are homopolymers of butadiene or copolymers of butadiene and acrylonitrile. The isomer content is largely cis/trans with vinyl (1,2-addition of butadiene) being 25% percent or less. They have reactive groups in both terminal positions of the polymer chain end and, optionally, may have additional reactive groups pendant on the chain. Hycar contains no solvent or other unreactive components. There are three types of reactive functional groups commercially available. They are carhoxyl, acrylate, vinyl, and secondary amine. 

Table 2 Typical CTBN Reactive Liquid Polymers...

McKillop, D. A., Morgan, D., and Woodhaus, R. T, Reactive liquid polymers of propylene sulfide, Polytn. Prepr, 10, 779, 1969. 

BFGoodrich Manual RLP-1, Hycaf Reactive Liquid Polymers Product Data, BFGoodrich Company, Specialty Polymers and Chemicals Division, June 1983. 

Hycai Reactive Liquid Polymers Preliminary Data Sheet AB-16, Hycai Reactive Liquid Polymer Modified Epoxy Adhesives Polyether Diamine Hardeners, BFGoodrich, August 1983. 

Caiboxyl reactive liquid polymers (CRLP) are chemically reactive with epoxy resins and capable of chain extension and crosslinking through the carboxyl groups. The reactions most important in adhesive applications are those with epoxide groups and with aliphatic hydroxyl groups. A list of several commercially available CRLP products is shown in Table 2. 

Reaction products of solid epoxy resins, e.g., DER 664 (Dow), and Hycar carboxyl reactive liquid polymers can be used to toughen solid epoxy resins for use in powder adhesives or coatings (see Table 4). 

Technical Literature on Hycar Carboxyl Reactive Liquid Polymers, The BFGoodrich Chemical Co. 

Elastomeric modifiers are used to increase the peel strength (toughness) of epoxy resin adhesives. The most commonly used elastomeric materials are functionally terminated polybutadiene resins made by the B.F. Goodrich Company, Chemical Group under the trade name of Hycar Reactive Liquid Polymers. Initially, carboxyl-terminated butadiene acrylonitrile (CTBN) resins were introduced the carboxyl terminated materials are usually adducted with the epoxy resin to improve compatibility and to increase the toughness. 

---