The present invention relates to thermally expandable microspheres at least partially prepared from bio-based monomers and to a process of their manufacture. The microspheres comprise a thermoplastic polymer shell encapsulating a blowing agent, wherein the thermoplastic polymer shell comprises a polymer being a homo- or copolymer of a lactone according to formula (1): ##STR00001##
wherein each of R.sub.1, R.sub.2, R.sub.3, R.sub.4, separately from one another, is selected from the group consisting of H and an alkyl group preferably with 1-4 carbon atoms. The invention further provides expanded microspheres, which can be used in a variety of applications.

A thermoplastic resin expanded bead and a molded article composed of the thermoplastic resin expanded beads are provided. The expanded bead includes a foam layer containing a thermoplastic resin. The expanded bead has a columnar shape, and has two or more and eight or less through-holes penetrating in the axial direction thereof. A ratio Ct/A of a total cross-sectional area Ct of the through-holes to a cross-sectional area A of the expanded bead in a cut surface obtained by cutting the expanded bead along a plane perpendicular to the axial direction at the center in the axial direction is 0.02 or more and 0.15 or less.

To provide a core material for a fiber reinforced composite having an excellent workability upon being composited with a fiber reinforcing material. A core material for a fiber reinforced composite of the present disclosure comprises a molded product of expanded beads containing a thermoplastic resin, and having a heat shrinkage onset temperature of 80 C. or higher, a linear expansion coefficient of 1010.sup.5 mm/mm.Math. C. or less, and a ratio of change in dimensions with heating at 130 C. of 4.0% to 0%.

The present invention relates to thermoplastic olefin elastomer expanded beads, having an average aspect ratio of 1.10 or less and an average circularity of 0.985 or more. The thermoplastic olefin elastomer expanded beads preferably have a crystal structure such that a melting peak inherent in the thermoplastic olefin elastomer (inherent peak) and one or more melting peaks on a higher temperature side than the inherent peak (high temperature peaks) appear on a DSC curve obtained when heating the expanded beads from 23 C. to 200 C. at a heating rate of 10 C./min.

The present invention provides expanded polylactic acid resin beads, in which each bead is composed of a core layer that is in an expanded state and contains a crystalline polylactic acid resin, and a coating layer that coats the core layer and contains a mixed resin of an amorphous polylactic acid resin and a crystalline polyolefin resin, wherein the content of the crystalline polyolefin resin in the coating layer is 3% by weight or more and less than 50% by weight. The expanded polylactic acid resin beads can stably produce a molded article of expanded polylactic acid resin beads excellent in fusibility of the expanded polylactic acid resin beads therein and also excellent in solvent resistance.

A bead expanded article has a plurality of expanded particles, in which the bead expanded article has a property that a value obtained by dividing a 10% compression stress (MPa) of the bead expanded article by a density (g/cm.sup.3) is 9.0 (MPa.Math.cm.sup.3/g) or more.

The invention relates to a process for the production of a foam having low organic compounds emissions, to polypropylene foamed products obtainable by the process, and to a process for the manufacture of low organic compounds emission articles comprising a foam for use in cars and food packaging. The process comprises the steps of: a) providing a foam comprising a propylene composition comprising a high melt strength propylene (HMS-PP) homopolymer or copolymer or combinations thereof, said HMS-PP foam having a melt strength of at least 25 cN at a maximum speed of at least 200 mm/s and a melting temperature of at least 135 C. and b) subjecting the HMS-PP foam to a thermal treatment at a temperature Tt which is preferably between 5 and 15 C. below the melting temperature Tm of the HMS-PP for a duration between preferably 1 and 10 minutes.

A process for the production of functionalized particle foam mouldings based on a thermoplastic base material with a glass transition temperature of at least 100 C. involves functionalization of base particles.

The present invention is concerned with an expanded beads molded article of expanded beads comprising a crosslinked multi-block copolymer containing a polyethylene block and an ethylene/-olefin copolymer block, wherein a density is 40 to 150 g/L; a gel fraction by a hot xylene extraction method is 30 to 70% by weight; a tensile elongation is 120% or more; a bead weight of the expanded beads is 0.8 to 8 mg; and the number of expanded beads per unit area on a surface of the expanded beads molded article is 5 to 30 per cm.sup.2, and is able to provide an expanded beads molded article which is light in weight and favorable in surface properties, fusion bondability, and durability.

Polyamide pre-expanded particles of this disclosure have a peak temperature of a maximum endothermic peak of 150-275 C. on a DSC curve obtained while being heated from 30 C. to 280 C. at a heating rate of 10 C./min using a DSC. The width of the peak is 30-80 C. when a straight line approximating the DSC curve on a high-temperature side relative to the peak after an end of melting is used as a baseline. The width corresponds to a difference between an extrapolated melting start temperature which is a temperature at an intersection point between a tangent line at an inflection point of the peak on a low-temperature side and the baseline, and an extrapolated melting end temperature which is a temperature at an intersection point between a tangent line at an inflection point of the peak on a high-temperature side and the baseline.