LDPE foams are semi-rigid. In order to impart more softness and resiliency to LDPE foams polar copolymers in the range between 10 % - 50 % are often added as part of the formulation. Suitable polar copolymers are poly butyl acrylat, poly methyl acrylat, poly ethyl acrylat and poly vinyl acetat. In order to be fit for use in their specific applications and markets, such as automotive, building and aerospace, excellent low temperature
properties are often very important. Polymers change their properties from rigid to more rubbery at the glass transition temperature. A low glass transition temperature of a polymer is therefore important to retain soft and flexible properties at low temperatures.

Left-hand figure compares the glass transition temperatures of some common polar copolymers. It can be seen that poly butyl acrylat has the lowest glass transition temperature. Consequently ethylen butyl acrylat (EBA) is the copolymer of choice for low temperature applications. Right-hand figure shows the elastic modulus of ethylen butyl acrylat (EBA) and ethylen vinyl acetat (EVA) as a function of temperature. The increase of modulus being equivalent with loosing flexibility, takes place for EBA at temperatures roughly -20 °C lower compared to EVA.

Therefore, ethylen butyl acrylat (EBA) in blend with LDPE is an excellent starting material to produce soft and resilient foams keeping these properties even at very low temperatures. Applications for EBA / LDPE foams include–among many others–pipe insulation, expansion joints, gaskets and camping mats. All Lucofin® grades as offered by LUCOBIT AG are based on ethylen butyl acrylat (EBA) making them perfectly suited to be
used in all polyolefin foams, especially in those foams where superior low temperatures properties are a must.