Subject: Dallas/Fort Worth; Biomaterials Researcher Needed; Strong Polymer Chemistry
From: richard_steinman@cmagroup.com
Date: 30 Oct 1996 16:33:42 -0800
Program Manager - Surgical Prod. Research; Dallas/Fort Worth. EDUCATION:
PhD in Chemistry, Chemical Engineering or Material Science and Engineering
emphasis on polymer science/chemistry. TECHNICAL/BACKGROUND: Strong polymer
synthesis background. An understanding of polymer structure-property relationship.
Proven technical creativity and leadership through both patents and publications.
This position is directed towards basic research of biopolymers. TECHNICAL
EXPERIENCE: 6 or more years of R&D; experience in polymers used in medical
devices. Exposure to FDA regulatory process, toxicology, biocompatibility,
material stability is preferred. MANAGEMENT/COMMUNICATION SKILLS: Demonstrated
skills in project management. Interpersonal skills and technical leadership
to participate in or lead multi-disciplinary program teams. Good presentation
and written communication skills. MOTIVATION, INTEREST AND ANALYTICAL
THINKING:Self-motivated. Strong interest in generating new concepts toward
successful products. Analytical thinking and problem solving skills. Bene
Burden at 38% of base $s. Position could be bonus eligible.
Please refer to JO# 527RJS in your response.
Richard Steinman.
Career Marketing Associates.
rjs@cmagroup.com
Richard has 15 Years Experience In Nationwide Engineering,Technical &
Scientific Search and Placement
Subject: Re: What's the best way to mesure the solvent quantity in polymer sample?
From: mrheadmstr@aol.com (MrHeadmstr)
Date: 31 Oct 1996 00:16:09 -0500
In article <5554u0$ei8@dawn.mmm.com>, jaspevacek@mmm.com (John Spevacek)
writes:
>bae@chem.postech.ac.kr (J.Y.Bae) wrote:
>>Hi everyone!
>>I am a graduate student in Korea.
>>
>>I want to mesure the solvent quantity in my polymer sample.
>>Maybe, there is solvent less than 0.5 wt% in sample.
>>How I can quantitivly and simply mesure the solvent quantity in my
sample?
>
>jaspevacek@mmm.com (John Spevacek) wrote:
>
>Dry a sample in the oven until it reaches a constant weight. Compare the
>weight of the sample before you dried it and then after you dried it.
>
>
That will work if the solvent is rather volatile, but won't work well if
the solvent has a b.p. anywhere near the m.p. of the polymer. Three
better methods:
1) TGA. Use thermogravimmetry to determine percentage of solvent, as
well as any mineral fillers, when the solvent is in the several % or
higher range.
2) If the solvent % is very low, use Pyrolysis/GC/MS. Establish an
external standard curve quantitated by absolute mass (a given peak area =
X nanograms, etc.). Accurately weigh the sample, I use ~10-15mg, volatize
the solvent without degrading the polymer and analyze. Utilize the
calibration curve and calculate the exact mass of solvent liberated by the
pyrolysis, and calculate the percentage of solvent in the solid sample.
3) Using a different solvent, dissolve the sample and run it by HPLC.