Banner for LabNotes
From Lab Notes
Contact Information
Forest Products Laboratory
One Gifford Pinchot Drive
Madison, WI 53726-2398
Phone: (608) 231-9200
Fax: (608) 231-9592


You are here: FPL Home  / Information Products & Services  / Publications

Requested Product

Title: Water-assisted compounding of cellulose nanocrystals into polyamide 6 for use as a nucleating agent for microcellular foaming

Source: Polymer

Author(s)Peng, Jun; Walsh, Philip J.; Sabo, Ronald C.; Turng, Lih-Sheng; Clemons, Craig M.

Publication Year: 2016  View PDF »

Category: Journal Articles
Associated Research Project(s):   FPL-4706-1B

Abstract: Cellulose nanocrystals (CNCs) are a biorenewable filler and can be an excellent nucleating agent for the development of microcellular foamed polymeric nanocomposites. However, their relatively low degradation temperature limits their use with engineering resins like polyamide 6 (PA6) in typical melt processing techniques such as injection molding, compounding, and extrusion. A water-assisted extrusion compounding process was investigated to directly compound CNC suspensions with PA6 without the need of predrying the CNCs. By using water as a plasticizer and reducing the processing temperature by 30°C, this process can mitigate the degradation of CNCs during compounding. The effects of the CNCs on the mechanical properties, crystal type, and microstructure of solid and microcellular foamed specimens were characterized. The CNCs primarily acted as a nucleating filler, affecting both the matrix crystal structure and, in foamed composites, the cell structure. The CNCs nucleated the a-crystalline form of PA6 and also acted as a foam cell nucleator, increasing cell density by an order of magnitude while significantly reducing cell size. The weight reduction of the foamed specimens was about 15%. Adding small amounts of CNCs also increased matrix orientation in the solid injection molded specimens. These factors helped to improve the mechanical performance, especially the modulus of elasticity. During water-assisted compounding, thermal hydrolysis of PA6 occurred and generated carbonecarbon double bonds, as evaluated by FTIR. However, the molecular weight reduction caused by hydrolysis was less than 5%. The total molecular weight reduction was around 18%, combined with the melt extrusion and injection molding processes.

Keywords: High-pressure water-assisted compounding; Microcellular injection molding; Cellulose nanocrystals; Polyamide 6; Crystal transformation

Publication Review Process: Formally Refereed

File size: 3,072 kb(s)

Date posted: 05/04/2016

This publication is also viewable on Treesearch:  view
RITS Product ID: 79117
Current FPL Scientists associated with this product (listed alphabetically)
Clemons, Craig M.
Materials Research Engineer
Sabo, Ronald C.
Research Materials Engineer

Additional items that might interest you
View the video celebrating FPL's 100 years of public service in 2010, from the producers of the Greatest Good....view

Research Highlights from FPL....view

Termite Eradication: A search for the Holy Grail.... view

Moisture Management in Residential Construction Series videos...view

Wood Floor Systems in Residential Construction Series videos....view
- FPL's Mission and Strategic Plan -

FPL's mission is to identify and conduct innovative wood and fiber utilization research that contributes to conservation and productivity of the forest resource, thereby sustaining forests, the economy, and quality of life. ... ..more »

- FPL Research Emphasis Areas -
Advanced Composites

As an integral part of the FPL mission, we improve the long-term sustainability of our Nation's forests by creating valuable composite products from biobased materials ... ..more »

Advanced Structures

The FPL has been in the forefront of wood-frame housing research since 1910 and has long been recognized as a world leader in such housing-related areas as engineered wood ... ..more »

Forest Biorefinery

We all know the compelling reasons that the United States needs to reduce its dependence on fossil fuels. Historically, the greatest increases in energy demand have been for transportation fuels ... ..more »


A leader in wood products research for over a century, the FPL is positioning itself to become the lead Federal research facility for the application of nanotechnology in forest products ... more »

Woody Biomass Utilization

Forests in the United States contain a substantial amount of small-diameter, overstocked, and underutilized material.FPL research projects are exploring the potential of the small-diameter ... ..more »