1 A CDRSP proposal to boost the forest productions leading on to developing advanced industrial and biomedical applications 2 Introduction

• The use of biodegradable resources such as the low valued pine resin-based materials can be a worthy precursor for synthesizing and modifying its nature to tailor for high valued industrial and biomedical applications. • The term ‘resin’ is generally referred to the plant sap or the exudate but this definition is somewhat obscure as it contains gums, mucilage, oils, waxes and latex. (1)

3 State of the art

• Rosins are solid form of resins obtained from pines and similar types of plants belonging to the conifer family, produced by heating fresh liquid resin to vaporize the volatile liquid terpene (large group of unsaturated hydrocarbons) components. • It is semi-transparent and varies in colour from yellow to black. The crude pine resin isolated by tapping the tree approximately contains 70% rosin, 15% turpentine and 15% debris and water. (2)

4 State of the art

• The use of pine rosins as a precursor for various applications over the last 30 or so years have declined in Portugal and the use of it per se have somewhat been made redundant by the progress of an alternate crop in eucalyptus due to its rapid growth and enhanced productivity. • Rosin is classified into three main types; gum rosin, wood rosin and tall rosin. Gum rosin is the most common rosin obtained from the pine trees by tapping the living pine tree. (3)

5 State of the art

6 Objectives

• The dry rosin is obtained as a pale yellow to brown coloured brittle solid subsequent to the removal of water and debris, after the separation of more volatile component of turpentine from the crude resins. • Once it is dissolved in organic solvents (hydrophobic) crude rosins retain its sticky features which can be utilized optimally as an adhesive or matrix for composites and possibly for additive manufacturing.

7 Objectives

• A convenient system for the formation of gums and mucilage that can be widely used and their mechanical properties, rheology and industrial application at a larger scale leading to a high end value product – higher returns for the pine industry. • The rosin nano scaled fibres will be employed as a precursor for bio-medical application as a sustainable resource.

8 Objectives

• Although the rosin fibres are considered both biocompatible and biodegradable hitherto they have not been employed significantly as a primary source for fibre scaffolding in biomedical applications such as tissue engineering across the board. • An incorporation of a biodegradable polymer such as PCL may be utilized as a means of strengthening the rosin fibres.

9 Detail work

• The solid material obtained subsequent to isolation of turpentine as a mixture of rosin acids is readily soluble in organic solvents (e.g. ethanol, chloroform, dichloromethane and dimethylformamide) can be utilized for various purposes as mentioned in the objectives. • Adhesive or mucilage production directly from rosins seem less complicated and cost effective due to its sticky nature.

10 Detail work

• The rheology and tensile strength of rosins can be studied by the use of certain organic solvent systems and probe for possible cross-linking for its enhanced properties. • The orientation of rosin/rosin-polymer fibres can be examined by the use of SEM images. The chemical functional groups of Polymer/Rosin fibres can be studied by FTIR results.

11 Detail work

• In addition to the rheology and tensile strength the use of thermal gravimetric analysis can be used to test its stability as a function of temperature which would be required in application that possesses greater strength. • Rosin fibres can be spun using an electric charge to generate electro-spun fibres - either nano or micro scale.

12 Detail work (Methods)

• The polymer induced electro-spun fibres with N,N-dimethyformamide (DMF) as the solvent shown to be of nano scale with a good orientation of formation. • The rosins require a solvent system usually of higher dielectric constant to afford homogeneous status hence the formation of fibres via electro-spining technique. • Usually a solvent such as DMF is widely associated in electro-spun fibres although acetic acid and butanone may be used with good electro-spining

ability. 13 Detail work (Methods)

• A surfactant/solvent may provide finer orientation of fibres with less beading on the collector due to a reduce surface tension it creates. • Nevertheless, the beaded fibres can be altered with a solvent that has a higher conductivity such as sodium chloride or triethylamine as they form ion complexes in the solution.

14 Detail work (Associate problems and overcoming)

• The use of certain organic solvents and their volatile nature especially halogenated materials can be regarded as complex during the work which associates health and safety concerns and care must be taken to work in a fume-hood or safety cabinet. • Some of the organic solvents may prove difficulties in complete dissolution due to various components in crude rosins – e.g, rosins do not completely dissolve in acetone

15 Detail work (Associate problems and overcoming)

• Crude rosins being a sticky material potentially could encounter work related issues during the electro-spinning such as fibre formation surrounding the apparatus hence measures may be taken to limit such problems. • Though electro-spinning provides a greater degree of fine fibre formation the use of a solvent system may not always be suitable to the rosin involvement.

16 Detail work

• An alternative method for electro-spinning is the melt spinning where no solvent is required and the rosin is melted and pumped through a spinneret or die consisting few to thousands of holes. • The molten fibres are cooled, solidified and collected on a take-up wheel. Melt spun technique is widely used for nylon 6,6 as it is one of the polymers that is not conveniently dissolve in organic solvents.

17 Detail work (Applications)

• An alternative to both of these methods is the force-spinning of the polymer material by means of a rotation motor connected to a spinneret with plenty of holes punched on and the fibres are directly collected on to a collector sheet. • The rosins have been known for its biocompatible nature hence the fibres obtained via either electro-spun or melt-spun may be utilized for bio-medical applications or tissue engineering as a means of sustainable product development.

18 Detail work (Applications)

• Drug-nanofibre conjugate system has been probed, and drugs or bioactive molecules have also been covalently bonded with electro- spun fibre surface through various strategies of chemical immobilization, (4) • The formation of drug-nanofibre conjugates allows to control the release by the breakup of the chemical bonds or to sustain the drug effect, especially biomolecules, such as growth factors, for a desirable period of time in tissue engineering.

19 Detail work (Applications)

• Among a variety of chemical immobilization techniques, primary amine and carboxyl groups are the most frequently applied reactions sites in biomolecules for conjugation. Functional groups in rosins can be probed for furtherance as they contain those functional groups as a mixture of rosin acids. • Moreover, nanofibres made from most of the commercially available polymers often lack functional groups to react with the drug molecules, the nano-fibre surface should be functionalized first with specific functional groups which can react with drug molecules. • With the use of rosin-related fibres such drawbacks can be compared and contrast.

20 Results, dissemination and divulgation

• During the project there will be dissemination programmes held to appraise the progress and subsequent training for the advancement of it. • This may be classified in Four steps as outlined below

21 Results, dissemination and divulgation

• Step 1: • The Source of the crude material • The crude pine resins from the community Portugal/(Brazil)Co-Supplier • Collection from the owners/trees • Small business holders

22 Results, dissemination and divulgation

• Step 2: • Industrial involvement • For the extraction of turpentine and other resin-based materials such as crude rosin acids • Variable amounts from smaller scale to larger scale

23 Results, dissemination and divulgation

• Step 3: • CDRSP • Crude rosin acids; for developing mucilages, electro-spun fibres, particulates, composite material, Incorporation with Cellulose, properties, characterization (research criteria) leading to a high end industrial/biomedical application.

24 Results, dissemination and divulgation

• Step 3 continued. • Dissemination – conferences are held in designated countries for awareness of the research in progress on semester/yearly basis • Training – training with related to the use of pine rosins as a sustainable resurce for the community via industrial and government participation

25 Results, dissemination and divulgation

• Step 4: • Industry II • Production – associated companies • The use of the applications as a high end value biomedical/industrial product

26 References

(1) Langenheim J H, Plant Resins chemistry evolution ecology and ethnobotany, Timbers Press, 2003 (2) Zhang J, Rosin-based chemicals and polymers, Smithers Rapra, 2012 (3) Maiti S, Das S, Maiti M, and Ray A, Polymer publications of renewable-Resource materials, Eds, C.E. Carraher and L. H. Sperling, Plenum press, NY, USA, 1983, p.129 (4) H. S. Yoo, T. G. Kim and T. G. Park, Advanced Drug Delivery Reviews, 2009, 61, 1033-1042. Z. Zhang, J. Hu and P. X. Ma, Advanced Drug Delivery Reviews, 2012, 64, 1129-1141

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