Isotactic polypropylene (iPP) exhibits an interesting polymorphic behavior [1-5], sharing four crystalline structures: monoclinic [alpha]-form [6, 7], trigonal [beta]-form [1, 8-12], triclinic [gamma]-form [13, 14] and smectic phase [15, 16], Among these crystalline forms, [beta]-form is a metastable phase and can only be obtained under the following processing conditions: melt crystallization in the presence of specific heterogeneous nucleating
agent (NA) [17, 18], by directional crystallization in certain temperature , or from melts subjected to shear [20, 21].
A new family of liquid nucleating
and clarifying agents is said to offer processors of PP and HDPE the ability to reduce cycle times while obtaining the cost and accuracy advantages of liquid additives.
These microstructures consist of semi-crystalline thermoplastics attached to nanoparticle nucleating
Hence, the nucleating
agent and the compatibilizer were used to improve tensile properties and compatibility of the PBAT/PLA composite films.
Multi-amides as very important materials have been widely used in synthetic intermediates , material chemistry , polymer [3, 4] and so on, due to their excellent antitumour, antibacterial and nucleating
properties , etc.
Micro-lamellar talcs, including the Mistrocell range, are said to make ideal nucleating
agents for new polyolefin-based foam composites used to produce lightweight materials with improved stiffness at lower densities.
Products representing these benefits at K 2013 will include: Millad NX 8000 and NX 8500E clarifying agents for PP; Hyperform HPN 68L, HPN-20E and HPN-600ei nucleating
agents for PP; Hyperform HPN-20E nucleating
agent for PE, and Hyperform HPR-803i reinforcing agent.
Milliken will also demonstrate the benefits of its nucleating
agent Hyperform HPN-600ei for better transparency and excellent visual appearance, lightweighting, and PET/PS replacement in thermoforming cups and trays.
In order for precipitation to occur, a nucleating
particle must be present to allow for aggregation of water molecules.
agents are also used in sheet and profile extrusion, such as pipe applications where they offer improved stiffness.
In simple terms, grain refining is the process of adding nucleating
material to the melt to initiate grain growth.
The European Food Safety Authority has approved the use of Hyperform[R] HPN-68 for use in food applications, which means that this high-speed nucleating
agent for polypropylene from Milliken & Co has now gained acceptance for food related applications virtually worldwide.