Additives crosslinking agents

Resoles are synthesized from a phenol to formaldehyde mole ratio less than one. They will harden (cure) on heating and in this respect contrast with Novolacs, which require an additional crosslinking agent for curing to occur. 

BMI was also used as a crosslinking agent for poly(iminoethylene). The Michael addition takes place with the nucleophilic nitrogen of the imino group and the double bonds of the electrophilic BMI. The Michael addition of BMI is now adopted as a crosslinking reaction for polymers with amino end groups [2]. 

Modified PAN fibres have been obtained from copolymers containing up to 15% or ISP units using the wet spinning process30. Some properties of modified fibres are presented in Table 1. For comparison are also given the properties of fibres obtained from copolymers additionally crosslinked with conventional crosslinking agents used in the vulcanization of nitrile rubbers. 

A crosslinked starch was described as a fluid loss additive for drilling fluids [632,1626]. The additive resists degradation and functions satisfactorily after exposure to temperatures of 250° F for periods of up to 32 hours. To obtain crosslinked starch, a crosslinking agent is reacted with granular starch in an aqueous slurry. The crosslinking reaction is controlled by a Brabender... 

Additives that assist the creation of a fracture include viscosifiers, such as polymers and crosslinking agents temperature stabilizers pH control agents and fluid loss control materials. Formation damage is reduced by such additives as gel breakers, biocides, surfactants, clay stabilizers, and gases. 

The concentration of a crosslinking agent containing zirconium in a gel is determined by first adding an acid to break the gel and converting the zirconium into the ionic (noncomplexed) form [340]. This is followed by the addition of... 

The crosslinking of a sulfonylated polyarylene ether sulfone was accomplished by addition of CDI and bis-4-aminophenylsulfone as crosslinking agents [23] a) Activation of the sulfonic acid group... 

---