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The Preparation of Nano Cellulose Whiskers / Polylactic Acid Composites

Zhen Wenjuan

Department of Sport Medicine,Cheng Du SportUniversity

Cheng Du Sport University

Cheng Du, 610041, P.R. Chinazsy_516@sohu.com

Shan Zhihua

Department of biomass and leather,Sichuan University

Sichuan University,Cheng Du, 610065, P.R. China

Abstract-The purpose of this study was to prepare a kind of

fully biodegradable nanocomposites for the sports industry.

As a completely biological material, This material had notonly special properties of nanomaterials, but also had the

rigidity of cellulose, dimensional stability and fully

biodegradable, at the same time, such material could also

solve the disposal problem of waste sports equipment. With

different mass fraction, cellulose nano whiskers were added

to the polylactic acid matrix, and the composites were

prepared by solution casting method, then nano-cellulose

whiskers / polylactic acid composites were successfully made.

Tests were carried out to study the water absorption,

degradation and membrane mechanical properties of the

composites. Compared with the pure polylactic acid, water

absorption and degradation of the composites increased

significantly with the mass fraction of nano-cellulose

whiskers increasing. Compared with pure PLA film, the

tensile strength and elongation at break of compositemembranes increased significantly. When the CNW mass

fraction was at 5% maximum, the mechanical properties of

nanocomposite got its maximum value. By solution casting,

Nano-cellulose whiskers and polylactic acid matrix

successfully were prepared into nanocomposites, which had

excellent mechanical properties and very good performance

at biological degradation.

Keywords-Cellulose whiskers; biological nano-composite

materials; mechanical properties

INTRODUCTION

Sports field is one of those industries using the mostadvanced plastic composite materials at the earliest. But

the man-made plastic composite not only consume thefossil resources but also cannot degradable. Reinforcement

of polymer composites with plant fiber instead of glassfiber is a way of improving these problems, yet such

composites are often of modest strength when both fiberand matrix are biobased and biodegradable

Natural polymers has the potential to take the place of

synthetic fiber as a reinforcing material in composite

materials for its abundant in resources, easy disposal afterabandoned, renewable and excellent in mechanical

properties. Polylactic acid (PLA) is a biodegradablelinear aliphatic thermoplastic polyester from renewableresources like cotton, corn, etc, which has good

mechanical properties, thermal plasticity , biocompatibility,

and readily fabricated. PLA is thus a promising polymer

for various end-use applications, Even when burned, itproduces no nitrogen oxide gases and only one-third of the

combustible heat generated by polyolefins, and it does notdamage the incinerator and provides significant energy

savings. However, as linear thermoplastic polyester, thestrength of PLA can not meet the requirements.

Nano-cellulose whiskers (CNW) could complex with

organic polymer matrix to reinforce the strength of matrix.Due to perfect crystalline arrangement of whiskers they

have high modulus and will potentially act as efficientreinforcing materials. The advantage of nanocomposite

materials is that the interface being ultra-microscopic, theinterfacial adhesion of matrix eliminated and enhancing

the problems of thermal expansion coefficient. So, CNWcan improve the mechanics and high temperature stability

properties [3-4].

1. EXPERIMENTAL

A. Materials

PLA was supplied by Chengdu Shudu pharmaceuticalCo., Ltd., dissolved with chloroform. CNW made by lab.Different mass fraction Suspensions were made with

DMAc / LiCl solutions.

B. Processing of nanocomposites

The composite materials were compounded using

solution casting. PLA, surfactant and CNW were stirred at80 . Using ultrasound and vacuum deaeration treatment,

the film left to evaporate in the oven for one day. 40 ,

vacuum drying for 2 weeks in order to remove all

remaining chloroform. The prepared films had a thicknessof 0.1 mm.

C. Characterization

1) Degradation and water absorption of films

Degradation tests: composite film (10.0cm10.0cm),precision weighing (M1), adding into flask with pH7.4,

15mL phosphate buffer solution (PBS), sealed, 37 ,

water bath shocking, taking the samples every 2 months,

vacuum drying, the weight measured after constantweight(M2). Weight loss of film was calculated by the

following formula.

2011 International Conference on Future Computer Science and Education

978-0-7695-4533-2/11 $26.00 2011 IEEE

DOI 10.1109/ICFCSE.2011.38

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application in biological medicine[J]Acta Polymerica Sinica,

1999, (3): 24-32.

[2] Petersson L, Oksman K. Preparation and properties of

biopolymer-based nanocomposite films using microcrystalline

cellulose[J]. American Chemical Society Symposium Series, 2006,

938: 132-150.

[3] Huang Z M., Zhang Y Z, Kotaki M. A review on polymer

nanofibers by electrospinning and their applications in

nanocomposite[J]s. Composites Science and Technology,

2003,63(15): 2223-2253.

[4] Gousse C, Chanzy H, Exoffier G,et al. Stable suspensions ofpartially silylated cellulose whiskers dispersed in organic

solvents[J]. Polymer, 2002, 43 (9):2645-2651.

[5] Hakkarainen M, Karlsson S. Weight losses and molecular weight

change correlated with the evolution of hydroxyacids in simulated

in vivo degradation of homo and copolymers of PLA[J]. Polym

Degra Drab, 1996, 52:283-291.

[6] Lee S H, Kira S H, Han Y K; et a1. Synthesis and degradation of

group-functionalized polylaetide[J]. Journal of Polymer Science,

Part A, Polymer Chemistry, 2001, 39: 973-985.

[7] L. Petersson et al. Structure and thermal properties of poly(lactic

acid)/cellulose whiskers nanocomposite materials[J]. CompositesScience and Technology, 2007, 67 :2535-2544.

[8] M.A.S. Azizi Samir et al. Cellulose nanocrystals reinforced

poly(oxyethylene) [J]. Polymer, 2004,45: 4149-4157.

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