In order to quantify our fluorogenic molecular probe studies on the radiation-induced polymerization of methyl methacrylate (MMA), measurements have been made of the monomer conversion, C M, and polymer molecular weight distribution as a function of dose for bulk MMA polymerized by steady-state (60Co γ-rays) and nanosecond-pulsed (3 MeV electrons) radiation. In all cases, C M was found to increase close to linearly with dose up to ca. 30%. Above this conversion, autoacceleration of polymerization (the gel or Trommsdorff effect) occurs in the γ-irradiated samples. From the low-conversion steady-state data, using dose-rates of 0.21 and 2.7 Gy/s, the parameter 〈k p〉 2 G(R.)/2〈k t〉 = 0.011 and 0.015 lmol-1 s-1 (100 eV)-1 respectively have been determined (with 〈k p〉 and 〈k t〉 the average rate coefficients for bimolecular propagation and termination respectively, and G(R.) the yield of the chain-initiating free radicals per 100 eV (G = 1 (100 eV)-1 0.1036 μ mol J-1)). From the 5 Hz repetitive pulse data the value of 〈k p〉 G(R.) = 1700 lmol-1 s-1 (100 eV)-1 has been determined. Taking 〈k p〉 = 342 lmol-1 s-1 from the literature results in G(R.) = 5.0 (100 eV)-1 and 〈k t〉 = 2.7 × 107 lmol-1 s-1.
Research on Chemical Intermediates – Springer Journals
Published: Oct 7, 2004
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera