Improved Superabsorbers Based on Sulfonated Pulps Art J. Ragauskas - - PowerPoint PPT Presentation

Improved Superabsorbers Based on Sulfonated Pulps

Art J. Ragauskas

PROJECT OBJECTIVE

• The objective of the proposed work is to provide a new

technology to enhance the water absorption properties of fully bleached softwood and hardwood Kraft pulps by 20 – 50%

• This goal will be accomplished by sulfonating the carbonyl

groups that are present in bleached Kraft pulps

• The results of this study will be a novel treatment for

improving the water absorbency properties of tissue, towel and fluff pulp

• This project will provide a viable alternative to petroleum

derived superabsorbers may used in modern products

Superabsorbers

• Superabsorbers are polymers, effectively absorb water,

hydrophilic cross-linked, cannot dissolve because of their three-dimensional polymeric network structure

• In the past 50 years, research in the field of superabsorbents

developed rapidly because of increasing demand

• Most superabsorbents are non-biodegradable polymer-based

products, the renewed public attention favoring environmentally benign products has encouraged the development of biodegradable superabsorbers based on cellulosic material

Functionalized Cellulose

• Oxidized cellulose, without chain cleaved,

characterization and derivatization

• Sulfonate oxidized cellulose, as disposable

absorbent products

Current Cellulose Modifications

O HO OH O OH O O O O OH O HO OH O OH

• O3S

SO3

• Oxidation

Sulfonation IO4

FQA measurement of cellulosic samples

ENTRY Arithmetic FQA Length (mm)

HW Original

0.809

Oxidation Low

0.794

Oxidation High

0.741

Sulfonation Low

0.771

Sulfonation High

0.683

Birch Original

0.705

Oxidation Low

0.675

Oxidation High

0.649

Sulfonation Low

0.658

Sulfonation High

0.632

Copper Number & Total Sufonation Group of Various Samples

Entry Total acid group (mmol/100 g o.d. fibers) Cellulose Cu # = 0.68 2.00 Oxidation 1: Cu # = 5.11 1.87 Sulfonation of Oxidation 1 3.55 Oxidation 2: Cu # = 7.13 1.79 Sulfonation of Oxidation 2 5.90 ECF Bleached Birch Cu # = 0.46 6.56 Oxidation 1: Cu # = 4.29 5.08 Sulfonation of Oxidation 1 6.94 Oxidation 2: Cu # = 5.98 3.50 Sulfonation of Oxidation 2 7.21

AFM of Native and Modified Cellulosics

Bleached HW Pulp Bleached Birch Kraft

Original Oxidized Sulfonated

Oxidized Sulfonated

Bleached HW Pulp

Low High

SEM Images of Native and Modified Cellulosics

WRVs`

ECF Bleached Birch Kraft Pulp

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 Birch Original Birch Oxidized 1 Birch Sulfonated 1 Birch Oxidized 2 Birch Sulfonated 2 WRV (g/g)

ECF Bleached HW Pulp

0.1 0.2 0.3 0.4 0.5 0.6 0.7 Buckeye Original Buckeye Oxidized 2 Buckeye Sulfonated 2 WRV (g/g)

Sulfonation of Cu # Provides higher WRV

• Sulfonation of bleached pulps with elevated Cu #

increases WRV up to 50%

• The impacts of these modifications were studies

including fiber dimensions, carbonyl, acid groups and their corresponding water absorbency properties as well as morphological changes

Preliminary Research Results

0.1 0.2 0.3 0.4 0.5 0.6 0.7 Kraft-A Kraft-A Kraft-A Kraft-A Kraft-A Kraft-A Kraft-B Kraft-B Cu #

Oxycellulose Content of Kraft ECF Pulps

All Bleached Kraft Pulps have a Cu #

0.2 0.4 0.6 0.8 1 1.2 1.4 K r a f t

• C

( S W ) K r a f t

• C

( S W ) K r a f t

• C

( S W ( P S / A Q ) ) K r a f t

• C

( S W ) K r a f t

• C

( S W ) K r a f t

• C

( S W ) K r a f t

• C

( E u c a l y p t u s ) K r a f t

• C

( S W ) K r a f t D K r a f t D K r a f t

• C

( S W p

• s

t

• D

2 ) Cu #

Oxycellulose Content of Kraft ECF Pulps

Proposed IPST@GT Research

• Determine Cu # of a series of ECF bleached kraft

pulps and sulfonate Cu # to 0 to increase the WRVs

• Identify best pulps for enhanced cellulosic based

superabsorber properties

• Investigate potential to enhance Cu # of ECF

bleached kraft pulp via modified peroxide (H2O2/metal) or alternative oxidant followed by sulfonation and the relationship between the absorbent properties and their chemi-physical properties.

Thank You