Foaming of aliphatic polyester using chemical blowing agent

Abstract

Poly(butylene adipate-co-succinate) (PBAS), a saturated aliphatic polyester cured by dicumyl peroxide (DCP), was prepared and the viscoelastic property was investigated. The viscosity of crosslinked PBAS increased, and it exhibited rubbery behavior as the content of curing agent was increased. The results suggested that the viscosity and elasticity of PBAS could be regulated by adding a small amount of DCP; hence, the processibility could be improved. Prior to foaming, a proper formulation of blowing agent (blowing agent/urea activator ϭ 100:8 phr) was examined to prepare expanded PBAS foam. Low-density PBAS expanded foams were prepared using a chemical blowing agent and DCP. The effect of the foaming temperature, additive content, and curing agent content on the blowing ratio and morphology of expanded PBAS foams was investigated. A closed-cell structure PBAS foam of high blowing ratio (density about 0.05 g/cm 3 ) could be obtained by adding 3 phr DCP. To manufacture expanded PBAS foam under 0.1 g/cm 3 using a chemical blowing agent, the storage modulus of the matrix polymer should exceed the loss modulus by enough to stabilize growing bubbles.

Preparation of polyethylene–octene elastomer foams by compression molding

“…100 h, 9 min, and 1 min, respectively), whereas AC starts to decompose around 205°C; this means that the decomposition of AC does not start when the crosslinking processing of POE is completed. The decomposition reaction of AC must take place when the polymer is at the proper melt viscosity or degree of cure 26. Activators can lower the decomposition temperatures of blowing agents.…”

Preparation and characterization of biodegradable poly(butylene succinate)(PBS) foams

“…3 Aliphatic polyesters have become one of the important classes of biodegradable polymers. 4 In recent years, a range of synthetic biodegradable resins based on synthetic aliphatic polyesters and their copolymers have been commercialized. Synthetic polyesters are generally produced by a polycondensation reaction of reactants that are obtained from the petrochemical feed stocks.…”

“…N,N'-Dinitroso pentatetramine is another cheap and widely used blowing agent in the plastic industry. 4 On the other hand, PBAs are usually volatile gases such as nitrogen, carbon dioxide and butane, and the blowing process requires special apparatus that has to be operated very carefully under strict conditions.…”

Properties of chlorinated polyethylene rubber/ethylene vinyl acetate copolymer blend‐based foam

“…In general, the temperature at which a large amount of decomposition starts for DCP is about 120°C, whereas AZDC starts to decompose around 205°C. The decomposition of AZDC must take place when the polymer is at the proper melt viscosity or degree of cure [15]. Activators can lower the decomposition temperatures of blowing agents.…”