Photo-polymerisation variables influence the structure and subsequent thermal response of dental resin matrices.
Photo-polymerisation variables influence the structure and subsequent thermal response of dental resin matrices.
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光聚合变量影响牙科树脂基质的结构和随后的热响应。
DOI：
10.1016/j.dental.2019.12.004
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Sirovica S
中科院分区：
文献类型：
--
作者：
Sirovica S
牙科树脂基复合材料的聚合物相结构对光聚合变量高度敏感。本研究的目的是了解如何不同的聚合物结构，产生不同的光聚合协议，响应于thermal perturbation.MethodsExperimental树脂制备了一系列的双-GMA/TEGDMA共混物（40/60，50/50和60/40重量%），用樟脑醌/DMAEMA或Lucirin TPO作为光引发剂体系。在相对“高”（3000 mW cm-2，6 s）或“低”（300 mW cm-2，60 s）的辐照度下，以圆盘几何形状对树脂进行光聚合，确保匹配的辐射曝光（18 J cm-2）。样品以5 °C min-1的速率从20 - 160 °C加热，同时以5 °C增量进行同步加速器X射线散射测量，以确定聚合物链段延伸和中程有序随温度的变化。对于每种独特的树脂组合物（n = 3），使用相同的加热方案，使用差示扫描量热法测量玻璃化转变温度。A配对t-检验被用来确定显着差异的玻璃化转变温度之间的辐照协议和光引发剂的化学在λ = 0.05。ResultsResins预聚合通过使用TPO和/或高辐照度表现出降低的链延伸率指示较低的热膨胀和较大的减少，在相对顺序加热时，低于玻璃化转变温度。以上的转变温度，在扩链速率的差异是可以忽略不计的，但较慢的转化系统表现出更大的相对秩序。不同的光引发剂系统或辐照protocols.SignificanceThe在加热过程中的扩链和中程秩序的演变的玻璃化转变温度之间没有显着差异取决于初始聚合物结构，这是由光聚合变量的影响。较不有序的系统，在更快的反应性基团转化率下产生的显示降低的链延伸低于玻璃化转变温度，并在整个加热过程中保持较低的秩序。
ObjectiveThe structure of the polymer phase of dental resin-based-composites is highly sensitive to photo-polymerisation variables. The objective of this study was to understand how different polymer structures, generated with different photo-polymerisation protocols, respond to thermal perturbation.MethodsExperimental resins were prepared from a series of Bis-GMA/TEGDMA blends (40/60, 50/50 and 60/40 wt.%), with either Camphorquinone/DMAEMA or Lucirin TPO as the photo-initiator system. Resins were photo-polymerised, in a disc geometry, at either relatively ‘high’ (3000 mW cm−2for 6 s) or ‘low’ (300 mW cm−2for 60 s) irradiances ensuring matched radiant exposures (18 J cm−2). Specimens were heated, from 20−160 °C at a rate of 5 °C min−1, whilst simultaneous synchrotron X-ray scattering measurements were taken at 5 °C increments to determine changes in polymer chain segment extension and medium-range order as a function of temperature. For each unique resin composition (n = 3), differential scanning calorimetry was used to measure glass transition temperatures using the same heating protocol. A paired t-test was used to determine significant differences in the glass transition temperature between irradiance protocols and photo-initiator chemistry atɑ= 0.05.ResultsResins pre-polymerised through the use of TPO and or high irradiances demonstrated a reduced rate of chain extension indicative of lower thermal expansion and a larger decrease in relative order when heated below the glass transition temperature. Above the transition temperature, differences in the rate of chain extension were negligible, but slower converted systems showed greater relative order. There was no significant difference in the glass transition temperature between different photo-initiator systems or irradiance protocols.SignificanceThe evolution of chain extension and medium-range order during heating is dependent on the initial polymer structure which is influenced by photo-polymerisation variables. Less ordered systems, generated at faster rates of reactive group conversion displayed reduced chain extension below the glass transition temperature and maintained lower order throughout heating.
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第 5 章 – 亚克力
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
B. Darvell
通讯作者：
B. Darvell
影响因子：
5
作者：
Feng, Li;Carvalho, Ricardo;Suh, Byoung I.
通讯作者：
Suh, Byoung I.
从硫化橡胶到乙烯基，树脂在牙科修复中的历史。
DOI：
--
发表时间：
2002
期刊：
The Journal of prosthetic dentistry (Print)
影响因子：
--
作者：
F. Rueggeberg
通讯作者：
F. Rueggeberg
影响因子：
5
作者：
Lovell, LG;Lu, H;Bowman, CN
通讯作者：
Bowman, CN
通过热分析、红外光谱和扫描电子显微镜表征牙科复合材料
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
C. Almeida;C. Mothé
通讯作者：
C. Mothé