Günümüzde mevcut doğal ve sentetik polimerik biyomalzemelerin modifikasyonu ve yeni
sentetik polimerik malzemelerin tasarımı çok ilgi çeken konulardır. Spesifik uygulamalar için
istenilen mekanik özellikler ve biyolojik aktiviteye sahip polimerlerin gerekliliği ortaya
çıkmıştır. Doğal polimerik biyomalzemelerin çeşitliliğindeki sınırlama ve kimyasal
modifikasyonunun zorluğu araştırmacıları yeni sentetik polimerik malzemelerin tasarımına
zorlamaktadır. Yeni alifatik poliesterler, polifosfoesterler, poliesteramitler, poliesterüretanlar,
polianhidritler üzerinde en çok durulan sentetik polimer grupları olarak öne çıkmaktadır.
Baz katalizli hidrojen transfer polimerizasyonu (HTP) ilk kez akrilamit monomerinden bir
alifatik poliamit olan naylon-3 (poli-β-alanin) elde edilmesinde ortaya çıkarılmış özel bir
anyonik katılma polimerizasyonu türüdür. HTP; akrilamit ve akrilik asit türevleri gibi vinil
grubu ve asidik oynak proton içeren bir monomer ve nükleofilik bir başlatıcı varlığında
gerçekleşmektedir. HTP ile bazı akrilamit, metakrilamit, akrilik asit ve metakrilik asit türevleri
monomer olarak kullanılarak poliamitler, poliesterler ve poli(ester eter)’ler elde edilmiştir.
Laktonların anyonik halka açılması polimerizasyonu ile karşılık gelen poliesterlerin sentezi ve
biyomedikal uygulamaları literatürde yaygın olarak bilinen çalışmalardır. Biyomedikal
uygulamalarda en yaygın kullanılan poliesterler ise poli(ε-kaprolakton) (PCL), poli(laktik asit)
(PLA), poli(glikolik asit ) (PGA) ve poli(3-hidroksi bütirat) (P3HB)’tır.
Tez çalışmasında, HTP ile polimerleşebilirliği en yüksek monomer olarak bilinen akrilamit ve
komonomer olarak β-bütirolakton (P3HB’nin monomeri) farklı oranlarda (% mol; 10, 25, 50,
75 ve 90) kullanılarak farklı bileşimlerde yeni poli(ester amit)’ler sentezlenmiştir. İzole edilen
kopolimerlerin bileşimi, ortalama mol kütleleri ve termal özellikleri sırasıyla elementel ve
spektroskopik analizler (FTIR ve NMR), MALDI ve termal analiz (DSC ve TGA) ile
aydınlatılmıştır. Spektroskopik yöntemlerden elde edilen sonuçlar değerlendirildiğinde
besleme oranlarından farklı ama yakın bileşimlerde ürünlerin elde edildiği belirlenmiştir.
Kopolimer bileşimini belirlemek için kullanılan NMR ve elementel analiz sonuçları birbiriyle
tutarlıdır. Elde edilen kopolimerler içerisinde en yüksek 5000-6000 g/mol ortalama mol
kütlesi değerine ulaşılmıştır. Kopolimerlerin DSC termogramlarında 0-10 oC arasında
gözlenen camsı geçiş sıcaklığı kaymaları ana zincirlerde ester bloklarının varlığını
kanıtlamaktadır. TGA termogramları ise yaklaşık 230 oC ve 330 oC merkezli iki basamaklı
termal bozunma göstermektedir.,Nowadays, biologically and synthetically derived biodegradable biopolymers have attracted
considerable attention. Diversity and complexity of in vivo environments cause the necessity
of more specific biopolymers for these application. Similarly, for a specific application,
necessity of polymers with desired biological activity and mechanical property have emerged.
Limitation of diversity in the natural polymeric materials and difficulties in their chemical
modification have forced investigators to begin designing of new synthetic polymeric
materials. New aliphatic polyesters, polyphospoesters, polyesteramides, polyesterurethanes
and polyanhidrides have come into prominence as the most elaborated synthetic polymer
groups.
Base-catalyzed hydrogen transfer polymerization (HTP) is a specific type of anionic addition
polymerization developed to obtain naylon-3, which is an aliphatic polyamide, from
acrylamide. HTP undergoes when one uses a monomer containing vinyl group and acidic
(loose) proton (such as acrylamide and acrylic acid derivatives) and a nucleophilic initiator
(also catalyst). HTP has been applied to some derivatives of acrylamide, methacrylamide,
acrylic acid and methacrylic acid and yielded novel polyamides, polyesters and poly(ether
ester)s. Synthesis of regarding polyester through anionic ring-opening polymerization of
lactones and their biomedical applications are well-known studies in literature. Most common
polyester used in biomedical applications are poly(ε-caprolactone) (PCL), poly(lactic acid)
(PLA), poly(glycolic acid) (PGA) and poly(3-hydroxy butyrate) (P3HB).
In the content of the thesis study, the highest polymerizability through HTP and the most
frequently used monomer, acrylamide, and β-butyrolactone (monomer of P3HB) as a
comonomer (% mole; 10, 25, 50, 75 ve 90) were used to synthesize a new poly(esteramide).
Compositions, average molar masses and thermal properties of the isolated copolymers were
elicited using by elemental and spectroscopic analyses (FTIR and NMR), mass spectrometry
(MALDI)-MS and thermal analysis (DSC and TGA), respectively. The products (copolymers)
were found to have compositions different from feed ratio but close when the results obtained
from spectroscopic methods were evaluated of spectroscopic methods. The methods used to
determime the copolymer composition were found to be consistent with each other. The
highest average mass of 5000-6000 g/mol were reached for the copolymers prepared. Glass
transition temperature shifts between 0 and 10 oC in the DSC thermograms of the copolymers
proves the existence of ester blocks in the main chains. TGA thermograms exhibit two-step
thermal decomposition shifts with centered at about 230 oC and 330oC.
Nowadays, biologically and synthetically derived biodegradable biopolymers have attracted
considerable attention. Diversity and complexity of in vivo environments cause the necessity
of more specific biopolymers for these application. Similarly, for a specific application,
necessity of polymers with desired biological activity and mechanical property have emerged.
Limitation of diversity in the natural polymeric materials and difficulties in their chemical
modification have forced investigators to begin designing of new synthetic polymeric
materials. New aliphatic polyesters, polyphospoesters, polyesteramides, polyesterurethanes
and polyanhidrides have come into prominence as the most elaborated synthetic polymer
groups.
Base-catalyzed hydrogen transfer polymerization (HTP) is a specific type of anionic addition
polymerization developed to obtain naylon-3, which is an aliphatic polyamide, from
acrylamide. HTP undergoes when one uses a monomer containing vinyl group and acidic
(loose) proton (such as acrylamide and acrylic acid derivatives) and a nucleophilic initiator
(also catalyst). HTP has been applied to some derivatives of acrylamide, methacrylamide,
acrylic acid and methacrylic acid and yielded novel polyamides, polyesters and poly(ether
ester)s. Synthesis of regarding polyester through anionic ring-opening polymerization of
lactones and their biomedical applications are well-known studies in literature. Most common
polyester used in biomedical applications are poly(ε-caprolactone) (PCL), poly(lactic acid)
(PLA), poly(glycolic acid) (PGA) and poly(3-hydroxy butyrate) (P3HB).
In the content of the thesis study, the highest polymerizability through HTP and the most
frequently used monomer, acrylamide, and β-butyrolactone (monomer of P3HB) as a
comonomer (% mole; 10, 25, 50, 75 ve 90) were used to synthesize a new poly(esteramide).
Compositions, average molar masses and thermal properties of the isolated copolymers were
elicited using by elemental and spectroscopic analyses (FTIR and NMR), mass spectrometry
(MALDI)-MS and thermal analysis (DSC and TGA), respectively. The products (copolymers)
were found to have compositions different from feed ratio but close when the results obtained
from spectroscopic methods were evaluated of spectroscopic methods. The methods used to
determime the copolymer composition were found to be consistent with each other. The
highest average mass of 5000-6000 g/mol were reached for the copolymers prepared. Glass
transition temperature shifts between 0 and 10 oC in the DSC thermograms of the copolymers
proves the existence of ester blocks in the main chains. TGA thermograms exhibit two-step
thermal decomposition shifts with centered at about 230 oC and 330oC.
