Poly(4,4'-diphenylene diphenylvinylene) was synthesised from 4,4' dibenzoylbiphenyl with TiCl4 and zinc dust as the catalyst and reducing agent respectively in THF. 4,4' -Dibenzoylbiphenyl was prepared via Friedel-Crafts reaction with benzoylchloride and biphenyl as starting materials. The cataÂlyst used was anhydrous AlCl3 Elemental analysis, GCMS chromatogram, FTIR spectrum and melting point measurement indicated that 4,4'Âdibenzoylbiphenyl was obtained with 100% purity. The polymer was successÂfully obtained with mass recovery of 72%. Glass transition, Tg and degradaÂtion, temperature, Td found were 196°C and 465°C, respectively. Number average molecular weight and weight average molecular weight found were 7,400 g/mol and 15,500 g/mol as measured by using gel permeation chromaÂtography. Conductivity of the pristine polymer was 8.3 x 10-11 Scm-I, whereas maximum conductivity found for LiCLO4 and iodine doped samples were 1.7 x 10-7 Scm-1 (2007 fold increase) and 5.5 x 10-9 Scm-1 (66 fold increase) with 18.75% and 37.50% of optimum doping contents respectively.
Poli(4,4'-difenilena difenilvinilena) telah disintesis daripada 4,4'Â-dibenzoilbifenil menggunakan TiCl4 dan serbuk zink masing-masing sebagai mangkin dan agen penurun di dalam THF. 4,4'-Dibenzoilbijenil telah disediakan melalui tindak balas Friedel-Crafts daripada benzoilklorida dan bijenil sebagai bahan mula dan AlCl3 kontang sebagai mangkin. Analisis unsur, kromatogram GCMS, spektrum FTIR dan penentuan takat lebur menunjukkan sebatian 4,4' -dibenzoilbifenil telah berjaya diperolehi dengan ketulenan 100%. Polimer telah berjaya disintesis dengan pengumpulan semula bahan sebanyak 72%. Suhu peralihan kaca, Tg dan suhu penguraian terma, Td bagi polimer masing-masing adalah 196°C dan 465°C. Kromatografi penelapan gel menunjukkan polimer yang dihasilkan mempunyai jisim molekul purata nombor dan jisim molekul purata berat masing-masing adalah 7,400 g/mol dan 15,500 g/mol. Kekonduksian polimer asal adalah 8.3 x 10-11 Scm-1, manakala kekonduksian maksimum polimer terdop LiClO4 dan iodin masing-masing adalah 1.7 x 10-7 Scm-I (peningkatan sebanyak 2007 kali ganda) dan 5.5 x 10-9 Scm-1 (peningkatan sebanyak 66 kali ganda) dengan kandungan agen pendop optimum sebanyak 18. 75% dan 37.50%.
Adunan polietilena berketumpatan rendah (LDPE)/getah asli cecair (LNR) dalam komposisi 100LDPE/0LNR, 70LDPE/30LNR, 60LDPE/40LNR dan 40LDPE/60LNR telah dihasilkan melalui penyebaran emulsi LDPE dan LNR.. LNR diperolehi melalui tindak balas pemekaan fotokimia ke atas getah asli (NR) dan emulsi LNR disediakan dengan menggunakan natrium dodesil sulfat (SDS) sebagai agen pengemulsi dan 1-heksanol sebagai ko-pengemulsi. Emulsi LDPE dihasilkan dengan cara yang sama menggunakan larutan LDPE dalam karbon tetraklorida, SDS dan 1-heksanol. Adunan LDPE/LNR disediakan melalui pencampuran emulsi LNR dan LDPE. Sifat mekanik adunan LDPE/LNR dianalisis melalui ujian regangan, hentaman dan kekerasan. Sifat mekanik optimum diperhatikan bagi adunan dengan komposisi 60LDPE/40LNR yang memberi nilai tegasan dan terikan yang maksimum. Suhu peralihan kaca, Tg, seperti yang diperolehi daripada analisis kalorimetri imbasan pembezaan (DSC) menunjukkan adunan yang dihasilkan adalah homogen. Kajian morfologi yang dilakukan dengan menggunakan mikroskop imbasan elektron (SEM) juga menunjukkan kehomogenan adunan yang dihasilkan.
Molecularly imprinted polymer (MIP) based on acrylate monomer was prepared at 80°C for 5 hours using p-xylene and ethylene glycol dimethacrylate (EGDMA) as a template and crosslinking agent respectively. The polymer obtained was washed with a mixture of acetic acid and methanol (1:4) and dried in the vacuum oven at 80°C. FTIR spectrum showed that all the templates were leached out from polymer during excessive washing and drying stage. The rebinding test result showed that the MIP was bonded with the analyte in the presence of organic solvents as shown by FTIR spectroscopy. The SEM micrograph showed that non-imprinted polymer (NIP) had no cavity as compared to MIP.
PEG at compositions of 10, 15 and 20 g were added into the initial formulation of hydrogel L, which was composed of
6 g low molecular weight chitosan (LMC) and 14 g poly (vinyl pyrrolidone) in 100 g of 2% lactic acid. The mixtures
were moulded and exposed to γ radiation at 7 kGy. The hydrogels obtained were characterized in term of gel fraction,
swelling property, syneresis effect, FTIR, XRD and cross section morphology. The results indicated PEG reduces almost
27% crosslinking density of the LMC-PVP hydrogel yet increased hydrogel’s water holding capacity from 450% and 480%
to 750% and 650% in phosphate buffer solution (PBS) at pH5.5 and pH7.0, respectively. Also PEG enhanced the ability
of LMC-PVP hydrogel to retain its moisture from dehydration at body temperature. The morphological study showed PEG
developed thick pores wall and reduced the pores size of the hydrogels’ network.
Komposit UPR/LNR/gentian kaca telah disediakan dengan menggunakan resin poliester tak tepu daripada hasil pengitaran semula bahan buangan PET. Kajian dimulai dengan pengitaran semula botol minuman PET melalui proses glikolisis dan hasilnya ditindakbalaskan dengan maleik anhidrida untuk mendapatkan resin poliester tak tepu. Kajian diteruskan dengan penyediaan adunan resin poliester tak tepu (UPR) dengan cecair getah asli (LNR) iaitu komposisi penambahan LNR ke dalam UPR telah diubah dari 0-7.5% (wt). Komposisi UPR/LNR dengan sifat mekanik terbaik dipilih sebagai matrik untuk penyediaan komposit berpenguat gentian kaca. Rawatan silana ke atas gentian kaca turut dilakukan dengan menggunakan (3-Aminopropil)triethoxysilane. Hasil daripada kajian mendapati adunan UPR/LNR dengan penambahan 2.5% LNR mempunyai sifat mekanik dan morfologi terbaik dengan partikel-partikel getah yang bersaiz kecil dapat tersebar dengan sekata dalam UPR. Kajian juga menunjukkan berlakunya peningkatkan dalam nilai tegasan, modulus regangan dan kekuatan hentaman bagi komposit UPR/LNR/gentian kaca terawat berbanding dengan penggunaan gentian tanpa rawatan.
In this study, poly(ethylene terephthalate) (PET) wastes bottle was recycled by glycolysis process using ethylene glycol. The unsaturated polyester resin (UPR) was then prepared by reacting the glycolysed product with maleic anhydride. The blend of UPR based on recycled PET wastes with liquid natural rubber (LNR) was carried out by varying the amount of LNR from 0 to 7.5 wt%. Mechanical tests such as tensile and impact were conducted to investigate the effects of LNR on the mechanical properties. Scanning Electron Microscopy (SEM) was used to analyze the morphology of the breaking area resulted from the tensile tests on the UPR and blend samples. From the results, the blend of 2.5 wt% LNR in UPR based recycled PET wastes achieved the highest strength in the mechanical properties and showed a well dispersed of elastomer particles in the sample morphology compared to other blends concentrations. This blend sample was then compared to the optimum blend of LNR with commercial resin through the glass transition temperature value Tg, mechanical strength and morphology properties. The comparison study showed that the Tg for UPR based recycled PET was higher than the value represented from commercial resin due to the degree of crystalinity in the molecular structure of the materials. LNR was found to be an effective impact modifier which gave a greater improvement in UPR from recycled PET wastes structure but not to the commercial one which needs 5% LNR to achieve the optimum properties. Thus, the compatibility between the UP resin based recycled PET and LNR was much better than with the commercial resin.