Adhesive degradation products

A product is only considered to be totally biodegradable if all its single components can be degraded naturally. Currently, pressure sensitive adhesives (PSA) are mostly based on non-biodegradable synthetic polymers such as polyacrylates, ethylene-vinyl acetate copolymers and styrene block copolymers [124]. Therefore there is a growing demand for the application of biodegradable PSAs on naturally degradable products like paper and cardboard. 

Hardening, embrittlement, gassing, accumulation of degradation products, viscous flow enhancement, change of adhesivity. 

Dimethyl hydrogen phosphite is used as a flame retardant on nylon 6 fibres, as a chemical intermediate in the production of pesticides and in lubricant additives and adhesives. No data on occupational exposure levels were available. A potential source of exposure to this chemical is from its occurrence as a degradation product of the chemical intermediate trimethyl phosphite and of pesticides such as trichlorphon and malathion (lARC, 1990). 

Phenol-formaldehyde type polymers had been the only exterior-durable adhesives for wood bonding, until the recent limited use of isocyanates. Both systems are petrochemical-based. Several researchers substituted carbohydrates for part of phenolic adhesives (1-4) > producing solid, fusible novolak resins. Recently, reaction of carbohydrate acid-degradation products with phenol and formaldehyde has produced liquid resols (5). Gibbons and Wondolowski (6,7) replaced a considerable amount of phenol with carbohydrate and urea to pro-... 

Peorsdike EIB, Gabnakis DK. Platelet adhesion to late fibrinogen degradation products. Blood Coag Fibrinolys 1996 7 353-360. 

Bisphenol A is used as a raw material to make polycarbonate and epoxy adhesives and can coatings. It is also used in flame-retardants, in unsaturated polyesters and in polyacrylate resins. Many foodstuff containers are made of these resins, including containers for oven and microwave cooking. Recent studies have shown that bisphenol type compounds have both mutagenic and cytotoxic properties [84]. Nerin et al. developed a fast screening method based on SPME and HPLC with fluorescence detection suitable for the analysis of several bisphenol derivatives and their degradation products in aqueous canned foods such as tuna, olives and corn [85]. The best results were obtained with carbowax and PDMS/DVB fibers. The detection limits were between 0.7 and 2.4ngmL while RSDs were between 14 and 32%. After the extraction parameters were optimized, the method was applied to... 

While the holes in the pellicle frame are effective in preventing particles from entering the space between the pellicle and mask, they are not effective in preventing airborne molecular contaminants such as ammonia, sulfur dioxide, water vapor, etc. from reaching this space. Under DUV illumination, these contaminants react together to form ammonium sulfate crystals on the reticle, discussed in Section 13.3.4. In addition, molecular contaminants can outgas from pellicle adhesives and from degradation products of the interaction of pellicles with DUV radiation. 

Cyanoacrylates are regarded as devices and are used in tissue adhesives to minimize the need for sutures and staples. Varying cyanoacrylates have varying toxicity profiles according to tiieir compositions and use. In the application of adhesives and other devices, where free monomer is present, the monomer is toxic. - The degradation products of some of these materials have also been formd to be toxic. 

---