NINGBO INNO PHARMCHEM CO.,LTD. understands that while Dipentaerythritol Hexaacrylate (DPHA), CAS 29570-58-9, offers exceptional performance benefits, formulators may encounter challenges related to its viscosity and the potential for brittleness in cured films. This article provides practical strategies for optimizing DPHA usage in UV/EB curable formulations.

Managing Viscosity: DPHA is characterized by a relatively high viscosity compared to lower-functionality monomers. This can impact ease of handling and application. To effectively manage viscosity, formulators have several proven strategies:

  1. Compounding with Low-Viscosity Monomers: The most common approach is to blend DPHA with low-viscosity monofunctional or difunctional acrylate monomers. Examples include isobornyl acrylate (IBOA), hexanediol diacrylate (HDDA), or tripropylene glycol diacrylate (TPGDA). These diluents significantly reduce the overall viscosity of the formulation, improving flow and application characteristics.
  2. Controlled Heating: For some applications, gently heating the formulation (e.g., to 40-60°C) can substantially lower the viscosity of DPHA and the overall mixture, facilitating easier processing without compromising cure speed or performance.
  3. Selecting Modified DPHA Variants: Certain modified versions of DPHA, such as ethoxylated dipentaerythritol hexaacrylate (e.g., PPTTA), offer improved fluidity while retaining high functionality. Exploring these specialized grades can be beneficial.

Preventing Brittleness: Highly cross-linked systems like those formed with DPHA can sometimes exhibit brittleness if not properly formulated. Brittleness can arise from excessive cross-linking density or overly rapid curing rates. To mitigate this:

  1. Adjust Monomer Ratios: If excessive functionality is suspected (e.g., >30% DPHA in the formulation), it's advisable to incorporate monofunctional monomers, such as lauryl acrylate (LA) or isobornyl acrylate (IBOA). These monomers can introduce flexibility into the polymer network. Alternatively, adjusting the proportion of flexible oligomers, such as polyurethane acrylates, can also help.
  2. Optimize Curing Rate: While fast curing is a benefit, excessively rapid curing can sometimes lead to internal stresses that manifest as brittleness. Adjusting UV light intensity (e.g., to 80-120 mW/cm²) or reducing the concentration of highly reactive photoinitiators can help control the curing speed, allowing the polymer network to form more uniformly and with less internal strain.

By thoughtfully implementing these formulation strategies, manufacturers can harness the exceptional performance of DPHA while ensuring optimal handling and preventing potential issues like brittleness. NINGBO INNO PHARMCHEM CO.,LTD. is here to support your formulation challenges, ensuring you get the most out of our high-quality DPHA for your UV curable systems.