Efficient Routes to Degradable and non-Degradable Renewable Polymers from Fatty Acids

For a sustainable pathway to plastics, exploitation of the renewable resources through green production procedures are discussed. The globally available renewable resources and their exploitation was overlooked; plant oils are highlighted. Thiol-ene addition and metathesis reactions for polymers are discussed. Polyesters, polyanhydrides, (&their copolymers) polyethylenes, poly(thio/oxo)ethers, and polyamides are prepared; material properties are studied and discussed

Nonisocyanate based polyurethane/silica nanocomposites and their coating performance

A series of silica nano-particles with different size were prepared by sol–gel technique, then surface modification by using cyclic carbonate functional organoalkoxysilane (CPS) was performed. Various amounts of carbonated silica particles directly added into carbonated soybean oil (CSBO) and carbonated polypropylene glycol (CPPG) resin mixture to prepare polyurethane–silica nanocomposite coating compositions by nonisocyanate route using an aliphatic diamine as a curing agent. Cupping, gloss, impact, and taber abrasion tests were performed on aluminum panels coated with those nano-composite formulations and tensile tests, thermogravimetric and SEM analyses were conducted on the free films prepared from the same coating formulations. An increase in abrasion resistance of CSBO-CPPG resin combination with the addition of silica was observed. In addition, the maximum weight loss of CSBO-CPPG resin combination was shifted to higher temperatures with incorporation of silica nano-particles The positive effect of modified silica particles on thermal stability of CSBO-CPPG system could be explained in such a way that PPG chains are able to disperse particles in the medium throughout the interactions between ether linkages and silanol groups

Poliüretan/silika nanokompozitler ve kaplama performanslarının incelenmesi

POLİÜRETAN/SİLİKA NANOKOMPOZİTLER VE KAPLAMA PERFORMANSININ İNCELENMESİ Bu çalışma izosiyanat içermeyen bir sentez yöntemi kullanarak silika nanopartiküllerle desteklenmiş bir poliüretan kaplama malzemesi geliştirmeyi amaçlamıştır. Böylece daha güvenli ve çevreye dost hem de daha sağlam bir malzeme elde edilmiştir. Bu amaçla ilk olarak silika nanopartikül sentezlenmiştir. Sentez yöntemi olarak Stöber Prosesi, olarak bilinen bir yöntem kullanılmıştır. Stöber Prosesi; çeşitli alkoksi silanların amonyak katalizörlüğünde birbirini takiben hidroliz ve kondensasyonu sonucu düşük sıcaklıklarda bile istenen büyüklükte hidrofilik silika kürecikler sentezlememizi mümkün kılmaktadır. Bu partiküllerin karakterizasyonu yapıldıktan sonra, gerçek bir hibrit malzeme oluşturmak yani organik faz ile inorganik faz arasında bir kovalent bağ oluşturmak amacıyla bu silika partiküllerin yüzeyi, yüzeyde bulunan silanol gruplarından faydalanılarak, uygun şekilde modifiye edilmiştir. Diğer taraftan temel kaplama malzemesi olarak kullanılmak üzere bir işlenmiş bitkisel kaynaklı yağ olan epokside soya yağı ve bir sentetik epoksi reçinesi olan polipropilenglikol diglisidileter reçineleri karbonatlanmış ve infrared ve nükleer magnetik rezonans spektroskopileri ile karakterize edilmişlerdir. Sonraki aşamada; uygun şekilde modifiye edilen silika ve karbonat reçineleri çeşitli kompozisyonlarda bir alifatik diamin bileşiği ile sertleştirilerek alüminyum yüzeylere kaplanmıştır. Yalnız soya yağı ve soya yağı ile polipropilenglikol diglisidileterin 1:1 karışımını ve de %0, 0.5, 1, 2 ve 4 oranında modifiye silikat içeren 10 ayrı formülasyon hazırlanmıştır. Son olarak yukarıda bahsedilen formülasyonlara sahip kaplanmış levhalar ve aynı formülasyonlardan elde edilen serbest filmler, ASTM ve DIN normlarına uygun olarak termal ve mekanik olarak test edilmişlerdir. ABSTRACT POLYURETHANE/SILICA NANOCOMPOSITES AND THE INVESTIGATION OF THEIR COATING MATERIALS This study was aimed to develop a silica nano-particle supported polyurethane coating material using a non-isocyanate synthesis method. Therefore, not only more reliable and environmental friendly, but also a stronger material has been achieved. For this reason, firstly, silica nanoparticle was synthesized. For synthesis method a process known as Stöber Process was used. Stöber process makes us prepare hydrophilic silica spheres within desired size range even at low temperatures by subsequent hydrolysis and condensation of various alcoxy silanes, which is catalyzed by ammonia. After the characterization of the particles synthesized, to make a covalent bond between organic and inorganic phases namely a real hybrid material the surface of the particles was modified properly through the silanol groups present at the surface. On the other side, an epoxy modified vegetable-originated oil, epoxidized soybean oil, and a synthetic epoxy resin, polypropylene glycol diglycidylether, were carbonated to be used as a base coating material and then characterized with infrared and nuclear magnetic resonance spectroscopy. In the next step, properly modified silicate particles and carbonate resins were mixed in different compositions. After addition an aliphatic diamine compound and applied on pre-treated aluminum plates and film moulds, the formulations were left to cure. The formulations consists of soy bean oil alone or its 1:1 mixture with polypropylene glycol and 0, 0.5, 1, 2, and 4% of modified silicate in each, giving totally 10 different composition. Finally, the coated plates with above mentioned formulations and the free films, which were made from the same formulations, are tested both thermally and mechanically according to the relevant ASTM and DIN norms

ADMET and TAD chemistry : a sustainable alliance

A versatile, additive-free post-polymerisation functionalisation method for acyclic diene metathesis (ADMET) derived polymers, utilising 1,2,4-triazoline-3,5-dione (TAD) chemistry, is reported. Several diene monomers have been synthesised starting from 10-undecenoic acid derivatives and subsequently polymerised via ADMET polymerisation reaction. Post-polymerisation functionalisation of the polyunsaturated macromolecules with several substituted TAD compounds was shown to achieve full conversions within 6 hours. Also, the functionalised polymers could be chemically crosslinked with a bivalent triazolinedione crosslinker. The glass transition temperature of the resulting materials could be tuned by varying the degree of functionalisation, the polymer backbone, the TAD substituent and the crosslinking density

One-pot modular synthesis of functionalized RAFT agents derived from a single thiolactone precursor

In this paper, the straightforward preparation of a range of functionalized trithiocarbonates as RAFT chain transfer agents (CTAs) is presented. The crucial step in the one-pot, three-step reaction sequence is the aminolysis of a thiolactone precursor as it introduces the desired functional handle (double bond, hydroxyl, furan, protected amine, ... ) and generates the corresponding thiol in situ, facilitating further elaboration of the CTA. Furthermore, the newly synthesized trithiocarbonates were positively evaluated as mediators in the RAFT polymerization of styrene, isobornyl acrylate, and N-isopropylacrylamide, while the presence of the end groups in the heterotelechic polymers was confirmed by NMR and UV-vis analysis