Hyperbranched Poly(amidoamine)s as Additives for Urea Formaldehyde Resin and Their Application in Particleboard Fabrication

Three types of hyperbranched poly(amidoamine)s (PAMAMs), namely HB(MA-EDA)1, HB(MA-EDA)3, and HB(MA-DETA)1.2, were synthesized and used as modifiers for urea-formaldehyde (UF) resin. Particleboards bonded with these modified UF resins were fabricated and evaluated. The results showed that these PAMA...

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Bibliographic Details
Main Authors: Jizhi Zhang, Siham Amirou, Hisham A. Essawy, Antonio Pizzi, Qiang Gao, Jianzhang Li
Format: Article
Language:English
Published: North Carolina State University 2014-12-01
Series:BioResources
Subjects:
Online Access:http://ojs.cnr.ncsu.edu/index.php/BioRes/article/view/BioRes_10_1_782_Zhang_Hyperbranched_Additives_Urea
Description
Summary:Three types of hyperbranched poly(amidoamine)s (PAMAMs), namely HB(MA-EDA)1, HB(MA-EDA)3, and HB(MA-DETA)1.2, were synthesized and used as modifiers for urea-formaldehyde (UF) resin. Particleboards bonded with these modified UF resins were fabricated and evaluated. The results showed that these PAMAMs caused some adverse effects on UF resin performance. The main problems of PAMAMs were their high buffer capacity and high pH values, which are attributed to the peripheral amino groups at the terminals, both of which had a serious negative influence on UF resin curing. These findings were supported by the gel time measurements in parallel with a predictive investigation on the resins using thermomechanical analysis (TMA). The gel time was prolonged, and the maximum modulus of elasticity (MOE) values decreased with the addition of HB(MA-EDA)3. The use of a strong acid curing agent (HCOOH) could reduce the gel time into a normal range; however the performance of the corresponding particleboards still deteriorated. Therefore, these PAMAMs are considered not suitable for the modification of UF resin when applied as final additives. Beyond all expectations, the modified UF resin that employed very finite amounts of HB(MA-EDA)1 as a pH regulator instead of NaOH yielded a considerable upgrade in performance of the produced particleboards.
ISSN:1930-2126
1930-2126