• 접착 및 계면
• /
• 제17권2호
• /
• pp.67-71
• /
• 2016

본 연구에서는 반응성 희석제 함량에 따라 접착강도 및 물성을 향상시키기 위해 polyether polyol/polyester polyol, 4,4-dicyclohexylmethane diisocyanate ($H_{12}MDI$), 2-butanone oxime (MEKO)를 사용하여 저점도 폴리우레탄 핫멜트를 합성하였다. 합성된 저점도 폴리우레탄 핫멜트의 물성은 FT-IR, viscosity meter 및 UTM 등을 통해 확인하였다. 반응성 희석제의 함량이 증가하고 NCO-blocked prepolymer가 감소함에 따라 저점도 폴리우레탄 핫멜트 접착제의 점도는 증가하였으며, OH-terminated oligomer, NCO-blocked prepolymer, 반응성 희석제 함량의 비가 1 : 0.5 : 0.5일 때 1.1 kgf/cm 접착강도를 나타내었다.

• 공업화학
• /
• 제21권1호
• /
• pp.46-51
• /
• 2010

양말단에 하이드록시프로필 기를 갖는 폴리올가노실옥산을 합성한 다음 이를 isophorone diisocyanate (IPDI), propylene glycol (PPG) 및 2,2-bis(hydroxymethyl) propionic acid (DMPA)와 함께 공중합하여 폴리올가노실옥산변성 폴리우레탄 중합체(PDMS- PU)를 제조하였다. 이중합체의 양말단에 있는 이소시아네이트기를 butanon oxime으로 blocking시킨 다음 트리에틸아민(TEA)으로 중화시켜 PDMS-PU 수분체를 얻었다. 열분해로 deblocking되는 온도를 측정하였으며 수분산체는 우수한 수분산 안정성을 보였다. 중합 시 NCO/OH의 당량비를 1.12~1.53으로 하고 DMPA의 함량을 변화시켜 제조한 PDMS-PU 중합체의 수분산체에 대한 분산입자크기를 측정하였으며 반응물에서 DMPA의 함량을 7.2, 13.5, 18.7 mole%로 증가시킴에 따라 입자의 크기는 136, 100, 65 dnm로 감소하는 경향을 나타내었다. DMPA의 함량을 변화시켜 얻은 PDMS- PU 필름의 접촉각 및 접착강도를 측정하였다.

• Macromolecular Research
• /
• 제13권5호
• /
• pp.427-434
• /
• 2005

To improve the performance and reduce raw material costs, blocked isocyanates were prepared with mixture of blocking agents in many industries. Three blocked isocyanates (adducts) namely $\varepsilon$-caprolactam/benzotriazole-blocked 4,4'-diphenylmethane diisocyanate (MDI), toluene-2,4-diisocyanate (TDI) and 4,4'-dicyclohexyl-methane diisocyanate ($H_{12}$MDI) were synthesized. Six reference adducts were also prepared by blocking MDI, TDI, and $H_{12}$MDI with $\varepsilon$-caprolactam ($\varepsilon$-CL) or benzotriazole. The reactions were carried out in acetone medium and dibutyltin dilaurate (DBTDL) was used as a catalyst. The progress of the blocking reaction was monitored by IR spectroscopy. De-blocking temperatures (dissociation temperatures) of these adducts were studied using DSC and TGA and the results were correlated. As expected, the thermal analysis data showed that de-blocking temperature of blocked aromatic isocyanates was lower than that of the blocked aliphatic isocyanates. The low de-blocking temperature of blocked aromatic isocyanate could be due to electron withdrawing benzene ring present in the blocked isocyanates. It was also found that benzotriazole-blocked adducts de-blocked at higher temperature compared with $\varepsilon$-CL-blocked adducts.

• 폴리머
• /
• 제37권2호
• /
• pp.232-239
• /
• 2013

A series of novel imidazole-blocked diisocyanate bioadhesives (IBAs) were synthesized from reaction of toluene 2, 4-diisocyanate (TDI), isophorone diisocyanate (IPDI), hydroxyl-terminated polylactide (HO-PLA-OH), 1,1,1-trimethylolpropane (TMP), and imidazole. Synthesis of IBAs was confirmed by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) revealed that the TDI-based IBA had lower thermal dissociation temperature and a faster deblocking rate than IBA based on IPDI. Hydroxyl-terminated polyurethane (HPU) was introduced to study the adhesive effect of the synthesized IBAs. Improvement on elastic modulus, tensile strength and water resistance of IBA-modified HPU in comparison with neat HPU suggested the good adhesive effect of IBA due to the strong chemical reaction between released NCO groups from IBA and hydroxyl groups from HPU.